diff --git a/examples/config.manyhosts.inc.php b/examples/config.manyhosts.inc.php
index b9ea89306d..ed2e8a0a6a 100644
--- a/examples/config.manyhosts.inc.php
+++ b/examples/config.manyhosts.inc.php
@@ -12,10 +12,10 @@ declare(strict_types=1);
 
 $i = 0;
 $hosts =  [
-    "foo.example.com",
-    "bar.example.com",
-    "baz.example.com",
-    "quux.example.com",
+    'foo.example.com',
+    'bar.example.com',
+    'baz.example.com',
+    'quux.example.com',
 ];
 
 foreach ($hosts as $host) {
diff --git a/examples/openid.php b/examples/openid.php
index 7cb456e78b..f3e9e5ef73 100644
--- a/examples/openid.php
+++ b/examples/openid.php
@@ -76,7 +76,7 @@ function Show_page($contents)
 function Die_error($e)
 {
     $contents = "<div class='relyingparty_results'>\n";
-    $contents .= "<pre>" . htmlspecialchars($e->getMessage()) . "</pre>\n";
+    $contents .= '<pre>' . htmlspecialchars($e->getMessage()) . "</pre>\n";
     $contents .= "</div class='relyingparty_results'>";
     Show_page($contents);
     exit;
@@ -143,7 +143,7 @@ if (isset($_POST['start'])) {
 
     $url = $authRequest->getAuthorizeURL();
 
-    header("Location: $url");
+    header('Location: ' . $url);
     exit;
 } else {
     /* Grab query string */
diff --git a/import_status.php b/import_status.php
index 9ca0e6fd84..1f7d488f8e 100644
--- a/import_status.php
+++ b/import_status.php
@@ -25,7 +25,7 @@ list(
 global $containerBuilder;
 
 // $_GET["message"] is used for asking for an import message
-if (isset($_GET["message"]) && $_GET["message"]) {
+if (isset($_GET['message']) && $_GET['message']) {
     // AJAX requests can't be cached!
     Core::noCacheHeader();
 
@@ -62,5 +62,5 @@ if (isset($_GET["message"]) && $_GET["message"]) {
         'go_back_url' => $_SESSION['Import_message']['go_back_url'],
     ]);
 } else {
-    ImportAjax::status($_GET["id"]);
+    ImportAjax::status($_GET['id']);
 }
diff --git a/js/messages.php b/js/messages.php
index 621e2696fb..b85102c1e3 100644
--- a/js/messages.php
+++ b/js/messages.php
@@ -456,7 +456,7 @@ $js_messages['strPrimaryKeyAdded'] = __('Primary key added.');
 $js_messages['strToNextStep'] = __('Taking you to next step…');
 $js_messages['strFinishMsg']
     = __("The first step of normalization is complete for table '%s'.");
-$js_messages['strEndStep'] = __("End of step");
+$js_messages['strEndStep'] = __('End of step');
 $js_messages['str2NFNormalization'] = __('Second step of normalization (2NF)');
 $js_messages['strDone'] = __('Done');
 $js_messages['strConfirmPd'] = __('Confirm partial dependencies');
@@ -685,22 +685,22 @@ $js_messages['strUpToDate'] = __('up to date');
 $js_messages['strCreateView'] = __('Create view');
 
 /* Error Reporting */
-$js_messages['strSendErrorReport'] = __("Send error report");
-$js_messages['strSubmitErrorReport'] = __("Submit error report");
+$js_messages['strSendErrorReport'] = __('Send error report');
+$js_messages['strSubmitErrorReport'] = __('Submit error report');
 $js_messages['strErrorOccurred'] = __(
-    "A fatal JavaScript error has occurred. Would you like to send an error report?"
+    'A fatal JavaScript error has occurred. Would you like to send an error report?'
 );
-$js_messages['strChangeReportSettings'] = __("Change report settings");
-$js_messages['strShowReportDetails'] = __("Show report details");
-$js_messages['strIgnore'] = __("Ignore");
+$js_messages['strChangeReportSettings'] = __('Change report settings');
+$js_messages['strShowReportDetails'] = __('Show report details');
+$js_messages['strIgnore'] = __('Ignore');
 $js_messages['strTimeOutError'] = __(
-    "Your export is incomplete, due to a low execution time limit at the PHP level!"
+    'Your export is incomplete, due to a low execution time limit at the PHP level!'
 );
 
 $js_messages['strTooManyInputs'] = __(
-    "Warning: a form on this page has more than %d fields. On submission, "
+    'Warning: a form on this page has more than %d fields. On submission, '
     . "some of the fields might be ignored, due to PHP's "
-    . "max_input_vars configuration."
+    . 'max_input_vars configuration.'
 );
 
 $js_messages['phpErrorsFound'] = '<div class="alert alert-danger" role="alert">'
@@ -768,7 +768,7 @@ $js_messages['strStructure'] = __('Structure');
 
 echo "var Messages = [];\n";
 foreach ($js_messages as $name => $js_message) {
-    Sanitize::printJsValue("Messages." . $name . "", $js_message);
+    Sanitize::printJsValue('Messages.' . $name . '', $js_message);
 }
 
 /* Calendar */
diff --git a/libraries/classes/Advisor.php b/libraries/classes/Advisor.php
index 5079020575..a22921bb83 100644
--- a/libraries/classes/Advisor.php
+++ b/libraries/classes/Advisor.php
@@ -565,7 +565,7 @@ class Advisor
 
         for ($i = 0; $i < $numLines; $i++) {
             $line = $file[$i];
-            if ($line == "" || $line[0] == '#') {
+            if ($line == '' || $line[0] == '#') {
                 continue;
             }
 
@@ -671,7 +671,7 @@ class Advisor
             $num = '<' . pow(10, -$precision);
         }
 
-        return "$num $per";
+        return $num . ' ' . $per;
     }
 
     /**
diff --git a/libraries/classes/Bookmark.php b/libraries/classes/Bookmark.php
index 58e8143849..0e7eae0a7c 100644
--- a/libraries/classes/Bookmark.php
+++ b/libraries/classes/Bookmark.php
@@ -134,9 +134,9 @@ class Bookmark
             return false;
         }
 
-        $query = "INSERT INTO " . Util::backquote($cfgBookmark['db'])
-            . "." . Util::backquote($cfgBookmark['table'])
-            . " (id, dbase, user, query, label) VALUES (NULL, "
+        $query = 'INSERT INTO ' . Util::backquote($cfgBookmark['db'])
+            . '.' . Util::backquote($cfgBookmark['table'])
+            . ' (id, dbase, user, query, label) VALUES (NULL, '
             . "'" . $this->dbi->escapeString($this->_database) . "', "
             . "'" . $this->dbi->escapeString($this->_user) . "', "
             . "'" . $this->dbi->escapeString($this->_query) . "', "
@@ -158,9 +158,9 @@ class Bookmark
             return false;
         }
 
-        $query  = "DELETE FROM " . Util::backquote($cfgBookmark['db'])
-            . "." . Util::backquote($cfgBookmark['table'])
-            . " WHERE id = " . $this->_id;
+        $query  = 'DELETE FROM ' . Util::backquote($cfgBookmark['db'])
+            . '.' . Util::backquote($cfgBookmark['table'])
+            . ' WHERE id = ' . $this->_id;
         return $this->dbi->tryQuery($query, DatabaseInterface::CONNECT_CONTROL);
     }
 
@@ -172,7 +172,7 @@ class Bookmark
     public function getVariableCount(): int
     {
         $matches = [];
-        preg_match_all("/\[VARIABLE[0-9]*\]/", $this->_query, $matches, PREG_SET_ORDER);
+        preg_match_all('/\[VARIABLE[0-9]*\]/', $this->_query, $matches, PREG_SET_ORDER);
         return count($matches);
     }
 
@@ -314,14 +314,14 @@ class Bookmark
             return [];
         }
 
-        $query = "SELECT * FROM " . Util::backquote($cfgBookmark['db'])
-            . "." . Util::backquote($cfgBookmark['table'])
+        $query = 'SELECT * FROM ' . Util::backquote($cfgBookmark['db'])
+            . '.' . Util::backquote($cfgBookmark['table'])
             . " WHERE ( `user` = ''"
             . " OR `user` = '" . $dbi->escapeString($cfgBookmark['user']) . "' )";
         if ($db !== false) {
             $query .= " AND dbase = '" . $dbi->escapeString($db) . "'";
         }
-        $query .= " ORDER BY label ASC";
+        $query .= ' ORDER BY label ASC';
 
         $result = $dbi->fetchResult(
             $query,
@@ -374,8 +374,8 @@ class Bookmark
             return null;
         }
 
-        $query = "SELECT * FROM " . Util::backquote($cfgBookmark['db'])
-            . "." . Util::backquote($cfgBookmark['table'])
+        $query = 'SELECT * FROM ' . Util::backquote($cfgBookmark['db'])
+            . '.' . Util::backquote($cfgBookmark['table'])
             . " WHERE dbase = '" . $dbi->escapeString($db) . "'";
         if (! $action_bookmark_all) {
             $query .= " AND (user = '"
@@ -383,9 +383,9 @@ class Bookmark
             if (! $exact_user_match) {
                 $query .= " OR user = ''";
             }
-            $query .= ")";
+            $query .= ')';
         }
-        $query .= " AND " . Util::backquote($id_field)
+        $query .= ' AND ' . Util::backquote($id_field)
             . " = '" . $dbi->escapeString((string) $id) . "' LIMIT 1";
 
         $result = $dbi->fetchSingleRow($query, 'ASSOC', DatabaseInterface::CONNECT_CONTROL);
diff --git a/libraries/classes/CentralColumns.php b/libraries/classes/CentralColumns.php
index 6a8e80fb03..752451ca14 100644
--- a/libraries/classes/CentralColumns.php
+++ b/libraries/classes/CentralColumns.php
@@ -264,9 +264,9 @@ class CentralColumns
         string $db,
         string $central_list_table
     ): string {
-        $type = "";
+        $type = '';
         $length = 0;
-        $attribute = "";
+        $attribute = '';
         if (isset($def['Type'])) {
             $extracted_columnspec = Util::extractColumnSpec($def['Type']);
             $attribute = trim($extracted_columnspec['attribute']);
@@ -276,10 +276,10 @@ class CentralColumns
         if (isset($def['Attribute'])) {
             $attribute = $def['Attribute'];
         }
-        $collation = isset($def['Collation']) ? $def['Collation'] : "";
-        $isNull = $def['Null'] == "NO" ? '0' : '1';
-        $extra = isset($def['Extra']) ? $def['Extra'] : "";
-        $default = isset($def['Default']) ? $def['Default'] : "";
+        $collation = isset($def['Collation']) ? $def['Collation'] : '';
+        $isNull = $def['Null'] == 'NO' ? '0' : '1';
+        $extra = isset($def['Extra']) ? $def['Extra'] : '';
+        $default = isset($def['Default']) ? $def['Default'] : '';
         return 'INSERT INTO '
             . Util::backquote($central_list_table) . ' '
             . 'VALUES ( \'' . $this->dbi->escapeString($db) . '\' ,'
@@ -319,7 +319,7 @@ class CentralColumns
         $central_list_table = $cfgCentralColumns['table'];
         $this->dbi->selectDb($db);
         $existingCols = [];
-        $cols = "";
+        $cols = '';
         $insQuery = [];
         $fields = [];
         $message = true;
@@ -381,7 +381,7 @@ class CentralColumns
             }
         }
         if (! empty($existingCols)) {
-            $existingCols = implode(",", array_unique($existingCols));
+            $existingCols = implode(',', array_unique($existingCols));
             $message = Message::notice(
                 sprintf(
                     __(
@@ -392,8 +392,8 @@ class CentralColumns
             );
             $message->addMessage(
                 Message::notice(
-                    "Please remove them first "
-                    . "from central list if you want to update above columns"
+                    'Please remove them first '
+                    . 'from central list if you want to update above columns'
                 )
             );
         }
@@ -475,7 +475,7 @@ class CentralColumns
             }
         }
         if (! empty($colNotExist)) {
-            $colNotExist = implode(",", array_unique($colNotExist));
+            $colNotExist = implode(',', array_unique($colNotExist));
             $message = Message::notice(
                 sprintf(
                     __(
@@ -559,7 +559,7 @@ class CentralColumns
                     $query .= ',';
                 }
             }
-            $query = trim($query, " ,") . ";";
+            $query = trim($query, ' ,') . ';';
             if (! $this->dbi->tryQuery($query)) {
                 if ($message === true) {
                     $message = Message::error(
@@ -648,7 +648,7 @@ class CentralColumns
         }
         $centralTable = $cfgCentralColumns['table'];
         $this->dbi->selectDb($cfgCentralColumns['db'], DatabaseInterface::CONNECT_CONTROL);
-        if ($orig_col_name == "") {
+        if ($orig_col_name == '') {
             $def = [];
             $def['Type'] = $col_type;
             if ($col_length) {
@@ -1098,7 +1098,7 @@ class CentralColumns
             $db,
             $selected_tbl
         );
-        $selectColHtml = "";
+        $selectColHtml = '';
         foreach ($columns as $column) {
             if (! in_array($column, $existing_cols)) {
                 $selectColHtml .= '<option value="' . htmlspecialchars($column) . '">'
@@ -1187,20 +1187,20 @@ class CentralColumns
         }
 
         return $this->template->render('database/central_columns/main', [
-            "db" => $db,
-            "total_rows" => $total_rows,
-            "max_rows" => $max_rows,
-            "pos" => $pos,
-            "char_editing" => $this->charEditing,
-            "attribute_types" => $attribute_types,
-            "tn_nbTotalPage" => $tn_nbTotalPage,
-            "tn_page_selector" => $tn_page_selector,
-            "tables" => $tables,
-            "rows_list" => $rows_list,
-            "rows_meta" => $rows_meta,
-            "types_upper" => $types_upper,
-            "pmaThemeImage" => $pmaThemeImage,
-            "text_dir" => $text_dir,
+            'db' => $db,
+            'total_rows' => $total_rows,
+            'max_rows' => $max_rows,
+            'pos' => $pos,
+            'char_editing' => $this->charEditing,
+            'attribute_types' => $attribute_types,
+            'tn_nbTotalPage' => $tn_nbTotalPage,
+            'tn_page_selector' => $tn_page_selector,
+            'tables' => $tables,
+            'rows_list' => $rows_list,
+            'rows_meta' => $rows_meta,
+            'types_upper' => $types_upper,
+            'pmaThemeImage' => $pmaThemeImage,
+            'text_dir' => $text_dir,
             'charsets' => $charsetsList,
         ]);
     }
diff --git a/libraries/classes/CheckUserPrivileges.php b/libraries/classes/CheckUserPrivileges.php
index 5c2c949054..dc4db1dff7 100644
--- a/libraries/classes/CheckUserPrivileges.php
+++ b/libraries/classes/CheckUserPrivileges.php
@@ -129,19 +129,19 @@ class CheckUserPrivileges
             // Ex. '... ALL PRIVILEGES on `mysql`.`columns_priv` .. '
             if ($show_grants_dbname == 'mysql') {
                 switch ($show_grants_tblname) {
-                    case "columns_priv":
+                    case 'columns_priv':
                         $GLOBALS['col_priv'] = true;
                         break;
-                    case "db":
+                    case 'db':
                         $GLOBALS['db_priv'] = true;
                         break;
-                    case "procs_priv":
+                    case 'procs_priv':
                         $GLOBALS['proc_priv'] = true;
                         break;
-                    case "tables_priv":
+                    case 'tables_priv':
                         $GLOBALS['table_priv'] = true;
                         break;
-                    case "*":
+                    case '*':
                         $GLOBALS['col_priv'] = true;
                         $GLOBALS['db_priv'] = true;
                         $GLOBALS['proc_priv'] = true;
diff --git a/libraries/classes/Config.php b/libraries/classes/Config.php
index 2245f47b19..aaefec9d97 100644
--- a/libraries/classes/Config.php
+++ b/libraries/classes/Config.php
@@ -305,7 +305,7 @@ class Config
 
         if (function_exists('gd_info')) {
             $gd_nfo = gd_info();
-            if (mb_strstr($gd_nfo["GD Version"], '2.')) {
+            if (mb_strstr($gd_nfo['GD Version'], '2.')) {
                 $this->set('PMA_IS_GD2', 1);
             } else {
                 $this->set('PMA_IS_GD2', 0);
@@ -573,7 +573,7 @@ class Config
                     }
                     // parse fanout table
                     $fanout = unpack(
-                        "N*",
+                        'N*',
                         substr($index_data, 8, 256 * 4)
                     );
 
@@ -1283,7 +1283,7 @@ class Config
     public function checkUploadSize(): void
     {
         if (! $filesize = ini_get('upload_max_filesize')) {
-            $filesize = "5M";
+            $filesize = '5M';
         }
 
         if ($postsize = ini_get('post_max_size')) {
diff --git a/libraries/classes/Config/ConfigFile.php b/libraries/classes/Config/ConfigFile.php
index f166cabfaa..dbcd10102e 100644
--- a/libraries/classes/Config/ConfigFile.php
+++ b/libraries/classes/Config/ConfigFile.php
@@ -414,21 +414,21 @@ class ConfigFile
 
         $path = 'Servers/' . $server;
         $dsn = 'mysqli://';
-        if ($this->getValue("$path/auth_type") == 'config') {
-            $dsn .= $this->getValue("$path/user");
-            if (! empty($this->getValue("$path/password"))) {
+        if ($this->getValue($path . '/auth_type') == 'config') {
+            $dsn .= $this->getValue($path . '/user');
+            if (! empty($this->getValue($path . '/password'))) {
                 $dsn .= ':***';
             }
             $dsn .= '@';
         }
-        if ($this->getValue("$path/host") != 'localhost') {
-            $dsn .= $this->getValue("$path/host");
-            $port = $this->getValue("$path/port");
+        if ($this->getValue($path . '/host') != 'localhost') {
+            $dsn .= $this->getValue($path . '/host');
+            $port = $this->getValue($path . '/port');
             if ($port) {
                 $dsn .= ':' . $port;
             }
         } else {
-            $dsn .= $this->getValue("$path/socket");
+            $dsn .= $this->getValue($path . '/socket');
         }
         return $dsn;
     }
@@ -445,11 +445,11 @@ class ConfigFile
         if (! isset($_SESSION[$this->_id]['Servers'][$id])) {
             return '';
         }
-        $verbose = $this->get("Servers/$id/verbose");
+        $verbose = $this->get('Servers/' . $id . '/verbose');
         if (! empty($verbose)) {
             return $verbose;
         }
-        $host = $this->get("Servers/$id/host");
+        $host = $this->get('Servers/' . $id . '/host');
         return empty($host) ? 'localhost' : $host;
     }
 
diff --git a/libraries/classes/Config/Form.php b/libraries/classes/Config/Form.php
index f8d6501d61..e9515a23db 100644
--- a/libraries/classes/Config/Form.php
+++ b/libraries/classes/Config/Form.php
@@ -105,11 +105,11 @@ class Form
     {
         $value = $this->_configFile->getDbEntry($optionPath);
         if ($value === null) {
-            trigger_error("$optionPath - select options not defined", E_USER_ERROR);
+            trigger_error($optionPath . ' - select options not defined', E_USER_ERROR);
             return [];
         }
         if (! is_array($value)) {
-            trigger_error("$optionPath - not a static value list", E_USER_ERROR);
+            trigger_error($optionPath . ' - not a static value list', E_USER_ERROR);
             return [];
         }
         // convert array('#', 'a', 'b') to array('a', 'b')
diff --git a/libraries/classes/Config/FormDisplay.php b/libraries/classes/Config/FormDisplay.php
index 0e69a89cd7..7ae6c7f027 100644
--- a/libraries/classes/Config/FormDisplay.php
+++ b/libraries/classes/Config/FormDisplay.php
@@ -141,7 +141,7 @@ class FormDisplay
         foreach ($this->_forms[$formName]->fields as $path) {
             $workPath = $serverId === null
                 ? $path
-                : str_replace('Servers/1/', "Servers/$serverId/", $path);
+                : str_replace('Servers/1/', 'Servers/' . $serverId . '/', $path);
             $this->_systemPaths[$workPath] = $path;
             $this->_translatedPaths[$workPath] = str_replace('/', '-', $workPath);
         }
@@ -243,8 +243,8 @@ class FormDisplay
             $formErrors = isset($this->_errors[$form->name])
                 ? $this->_errors[$form->name] : null;
             $htmlOutput .= $this->formDisplayTemplate->displayFieldsetTop(
-                Descriptions::get("Form_{$form->name}"),
-                Descriptions::get("Form_{$form->name}", 'desc'),
+                Descriptions::get('Form_' . $form->name),
+                Descriptions::get('Form_' . $form->name, 'desc'),
                 $formErrors,
                 ['id' => $form->name]
             );
@@ -310,7 +310,7 @@ class FormDisplay
         if ($tabbedForm) {
             $tabs = [];
             foreach ($this->_forms as $form) {
-                $tabs[$form->name] = Descriptions::get("Form_$form->name");
+                $tabs[$form->name] = Descriptions::get('Form_' . $form->name);
             }
             $htmlOutput .= $this->formDisplayTemplate->displayTabsTop($tabs);
         }
@@ -349,7 +349,7 @@ class FormDisplay
             $jsLangSent = true;
             $jsLang = [];
             foreach ($this->_jsLangStrings as $strName => $strValue) {
-                $jsLang[] = "'$strName': '" . Sanitize::jsFormat($strValue, false) . '\'';
+                $jsLang[] = "'" . $strName . "': '" . Sanitize::jsFormat($strValue, false) . '\'';
             }
             $js[] = "$.extend(Messages, {\n\t"
                 . implode(",\n\t", $jsLang) . '})';
@@ -452,7 +452,7 @@ class FormDisplay
                 }
                 return $htmlOutput;
             case 'NULL':
-                trigger_error("Field $systemPath has no type", E_USER_WARNING);
+                trigger_error('Field ' . $systemPath . ' has no type', E_USER_WARNING);
                 return null;
         }
 
@@ -707,8 +707,8 @@ class FormDisplay
                 $values[$systemPath] = $_POST[$key];
                 if ($changeIndex !== false) {
                     $workPath = str_replace(
-                        "Servers/$form->index/",
-                        "Servers/$changeIndex/",
+                        'Servers/' . $form->index . '/',
+                        'Servers/' . $changeIndex . '/',
                         $workPath
                     );
                 }
@@ -731,7 +731,7 @@ class FormDisplay
                 foreach ($values[$path] as $value) {
                     $matches = [];
                     $match = preg_match(
-                        "/^(.+):(?:[ ]?)(\\w+)$/",
+                        '/^(.+):(?:[ ]?)(\\w+)$/',
                         $value,
                         $matches
                     );
@@ -741,7 +741,7 @@ class FormDisplay
                         $proxies[$ip] = trim($matches[2]);
                     } else {
                         // save also incorrect values
-                        $proxies["-$i"] = $value;
+                        $proxies['-' . $i] = $value;
                         $i++;
                     }
                 }
@@ -846,7 +846,7 @@ class FormDisplay
             }
             if (! function_exists('recode_string')) {
                 $opts['values']['recode'] .= ' (' . __('unavailable') . ')';
-                $comment .= ($comment ? ", " : '') . sprintf(
+                $comment .= ($comment ? ', ' : '') . sprintf(
                     __('"%s" requires %s extension'),
                     'recode',
                     'recode'
diff --git a/libraries/classes/Config/FormDisplayTemplate.php b/libraries/classes/Config/FormDisplayTemplate.php
index c31d7c91a0..cfb48a2ab4 100644
--- a/libraries/classes/Config/FormDisplayTemplate.php
+++ b/libraries/classes/Config/FormDisplayTemplate.php
@@ -223,7 +223,7 @@ class FormDisplayTemplate
                     $icons[$k] = sprintf(
                         '<img alt="%s" src="%s"%s>',
                         $v[1],
-                        "../themes/pmahomme/img/{$v[0]}.png",
+                        '../themes/pmahomme/img/' . $v[0] . '.png',
                         $title
                     );
                 }
@@ -279,7 +279,7 @@ class FormDisplayTemplate
             $htmlOutput .= __(
                 'This setting is disabled, it will not be applied to your configuration.'
             );
-            $htmlOutput .= '">' . __('Disabled') . "</span>";
+            $htmlOutput .= '">' . __('Disabled') . '</span>';
         }
 
         if (! empty($description)) {
@@ -371,7 +371,7 @@ class FormDisplayTemplate
         }
         if (isset($opts['setvalue']) && $opts['setvalue']) {
             $htmlOutput .= '<a class="set-value hide" href="#'
-                . htmlspecialchars("$path={$opts['setvalue']}") . '" title="'
+                . htmlspecialchars($path . '=' . $opts['setvalue']) . '" title="'
                 . sprintf(__('Set value: %s'), htmlspecialchars($opts['setvalue']))
                 . '">' . $icons['edit'] . '</a>';
         }
@@ -491,7 +491,7 @@ class FormDisplayTemplate
                 $vArgs[] = Sanitize::escapeJsString($arg);
             }
             $vArgs = $vArgs ? ", ['" . implode("', '", $vArgs) . "']" : '';
-            $jsArray[] = "registerFieldValidator('$fieldId', '$vName', true$vArgs)";
+            $jsArray[] = "registerFieldValidator('" . $fieldId . "', '" . $vName . "', true" . $vArgs . ')';
         }
     }
 
diff --git a/libraries/classes/Config/ServerConfigChecks.php b/libraries/classes/Config/ServerConfigChecks.php
index 8f9d2cff73..741533c83c 100644
--- a/libraries/classes/Config/ServerConfigChecks.php
+++ b/libraries/classes/Config/ServerConfigChecks.php
@@ -148,7 +148,7 @@ class ServerConfigChecks
         $serverCnt = $this->cfg->getServerCount();
         for ($i = 1; $i <= $serverCnt; $i++) {
             $cookieAuthServer
-                = ($this->cfg->getValue("Servers/$i/auth_type") == 'cookie');
+                = ($this->cfg->getValue('Servers/' . $i . '/auth_type') == 'cookie');
             $cookieAuthUsed |= $cookieAuthServer;
             $serverName = $this->performConfigChecksServersGetServerName(
                 $this->cfg->getServerName($i),
@@ -167,11 +167,11 @@ class ServerConfigChecks
             // $cfg['Servers'][$i]['ssl']
             // should be enabled if possible
             //
-            if (! $this->cfg->getValue("Servers/$i/ssl")) {
-                $title = Descriptions::get('Servers/1/ssl') . " ($serverName)";
+            if (! $this->cfg->getValue('Servers/' . $i . '/ssl')) {
+                $title = Descriptions::get('Servers/1/ssl') . ' (' . $serverName . ')';
                 SetupIndex::messagesSet(
                     'notice',
-                    "Servers/$i/ssl",
+                    'Servers/' . $i . '/ssl',
                     $title,
                     __(
                         'You should use SSL connections if your database server '
@@ -196,15 +196,15 @@ class ServerConfigChecks
             // $cfg['Servers'][$i]['auth_type']
             // warn about full user credentials if 'auth_type' is 'config'
             //
-            if ($this->cfg->getValue("Servers/$i/auth_type") == 'config'
-                && $this->cfg->getValue("Servers/$i/user") != ''
-                && $this->cfg->getValue("Servers/$i/password") != ''
+            if ($this->cfg->getValue('Servers/' . $i . '/auth_type') == 'config'
+                && $this->cfg->getValue('Servers/' . $i . '/user') != ''
+                && $this->cfg->getValue('Servers/' . $i . '/password') != ''
             ) {
                 $title = Descriptions::get('Servers/1/auth_type')
-                    . " ($serverName)";
+                    . ' (' . $serverName . ')';
                 SetupIndex::messagesSet(
                     'notice',
-                    "Servers/$i/auth_type",
+                    'Servers/' . $i . '/auth_type',
                     $title,
                     Sanitize::sanitizeMessage(sprintf(
                         __(
@@ -226,14 +226,14 @@ class ServerConfigChecks
             // $cfg['Servers'][$i]['AllowNoPassword']
             // serious security flaw
             //
-            if ($this->cfg->getValue("Servers/$i/AllowRoot")
-                && $this->cfg->getValue("Servers/$i/AllowNoPassword")
+            if ($this->cfg->getValue('Servers/' . $i . '/AllowRoot')
+                && $this->cfg->getValue('Servers/' . $i . '/AllowNoPassword')
             ) {
                 $title = Descriptions::get('Servers/1/AllowNoPassword')
-                    . " ($serverName)";
+                    . ' (' . $serverName . ')';
                 SetupIndex::messagesSet(
                     'notice',
-                    "Servers/$i/AllowNoPassword",
+                    'Servers/' . $i . '/AllowNoPassword',
                     $title,
                     __('You allow for connecting to the server without a password.')
                     . ' ' . $sSecurityInfoMsg
@@ -284,7 +284,7 @@ class ServerConfigChecks
         $serverId
     ) {
         if ($serverName == 'localhost') {
-            $serverName .= " [$serverId]";
+            $serverName .= ' [' . $serverId . ']';
             return $serverName;
         }
         return $serverName;
diff --git a/libraries/classes/Config/Validator.php b/libraries/classes/Config/Validator.php
index 11503a426a..dcd59e7e07 100644
--- a/libraries/classes/Config/Validator.php
+++ b/libraries/classes/Config/Validator.php
@@ -431,7 +431,7 @@ class Validator
             $line = trim($line);
             $matches = [];
             // we catch anything that may (or may not) be an IP
-            if (! preg_match("/^(.+):(?:[ ]?)\\w+$/", $line, $matches)) {
+            if (! preg_match('/^(.+):(?:[ ]?)\\w+$/', $line, $matches)) {
                 $result[$path][] = __('Incorrect value:') . ' '
                     . htmlspecialchars($line);
                 continue;
diff --git a/libraries/classes/Controllers/Database/QueryByExampleController.php b/libraries/classes/Controllers/Database/QueryByExampleController.php
index 5c728c22fd..2cd2ce263f 100644
--- a/libraries/classes/Controllers/Database/QueryByExampleController.php
+++ b/libraries/classes/Controllers/Database/QueryByExampleController.php
@@ -109,7 +109,7 @@ class QueryByExampleController extends AbstractController
          */
         $message_to_display = false;
         if (isset($_POST['submit_sql']) && ! empty($sql_query)) {
-            if (0 !== stripos($sql_query, "SELECT")) {
+            if (0 !== stripos($sql_query, 'SELECT')) {
                 $message_to_display = true;
             } else {
                 $goto = Url::getFromRoute('/database/sql');
diff --git a/libraries/classes/Controllers/Database/StructureController.php b/libraries/classes/Controllers/Database/StructureController.php
index f9c01434c5..741160c9c5 100644
--- a/libraries/classes/Controllers/Database/StructureController.php
+++ b/libraries/classes/Controllers/Database/StructureController.php
@@ -253,7 +253,7 @@ class StructureController extends AbstractController
         $json['changes'] = $changes;
         if (! $changes) {
             $json['message'] = $this->template->render('components/error_message', [
-                'msg' => __("Favorite List is full!"),
+                'msg' => __('Favorite List is full!'),
             ]);
             return $json;
         }
@@ -270,7 +270,7 @@ class StructureController extends AbstractController
         $json['list'] = $favoriteInstance->getHtmlList();
         $json['anchor'] = $this->template->render('database/structure/favorite_anchor', [
             'table_name_hash' => md5($favoriteTable),
-            'db_table_name_hash' => md5($this->db . "." . $favoriteTable),
+            'db_table_name_hash' => md5($this->db . '.' . $favoriteTable),
             'fav_params' => $favoriteParams,
             'already_favorite' => $alreadyFavorite,
             'titles' => $titles,
diff --git a/libraries/classes/Controllers/ErrorReportController.php b/libraries/classes/Controllers/ErrorReportController.php
index 09f46f2f8b..892194c803 100644
--- a/libraries/classes/Controllers/ErrorReportController.php
+++ b/libraries/classes/Controllers/ErrorReportController.php
@@ -95,13 +95,13 @@ class ErrorReportController extends AbstractController
                 } else {
                     $decoded_response = json_decode($server_response, true);
                     $success = ! empty($decoded_response) ?
-                        $decoded_response["success"] : false;
+                        $decoded_response['success'] : false;
                 }
 
                 /* Message to show to the user */
                 if ($success) {
                     if ((isset($_POST['automatic'])
-                            && $_POST['automatic'] === "true")
+                            && $_POST['automatic'] === 'true')
                         || $cfg['SendErrorReports'] == 'always'
                     ) {
                         $msg = __(
@@ -152,10 +152,10 @@ class ErrorReportController extends AbstractController
 
                 /* Persist always send settings */
                 if (isset($_POST['always_send'])
-                    && $_POST['always_send'] === "true"
+                    && $_POST['always_send'] === 'true'
                 ) {
                     $userPreferences = new UserPreferences();
-                    $userPreferences->persistOption("SendErrorReports", "always", "ask");
+                    $userPreferences->persistOption('SendErrorReports', 'always', 'ask');
                 }
             }
         } elseif (! empty($_POST['get_settings'])) {
diff --git a/libraries/classes/Controllers/GisDataEditorController.php b/libraries/classes/Controllers/GisDataEditorController.php
index 2bcd71fd57..d96d695f9a 100644
--- a/libraries/classes/Controllers/GisDataEditorController.php
+++ b/libraries/classes/Controllers/GisDataEditorController.php
@@ -56,7 +56,7 @@ class GisDataEditorController extends AbstractController
                 $gis_data['gis_type'] = mb_substr(
                     $_POST['value'],
                     $start,
-                    mb_strpos($_POST['value'], "(") - $start
+                    mb_strpos($_POST['value'], '(') - $start
                 );
             }
             if (! isset($gis_data['gis_type'])
diff --git a/libraries/classes/Controllers/Server/DatabasesController.php b/libraries/classes/Controllers/Server/DatabasesController.php
index c35d303bd1..cf20571ff2 100644
--- a/libraries/classes/Controllers/Server/DatabasesController.php
+++ b/libraries/classes/Controllers/Server/DatabasesController.php
@@ -357,14 +357,14 @@ class DatabasesController extends AbstractController
             foreach ($replicationTypes as $type) {
                 if ($replication_info[$type]['status']) {
                     $key = array_search(
-                        $database["SCHEMA_NAME"],
+                        $database['SCHEMA_NAME'],
                         $replication_info[$type]['Ignore_DB']
                     );
                     if (strlen((string) $key) > 0) {
                         $replication[$type]['is_replicated'] = false;
                     } else {
                         $key = array_search(
-                            $database["SCHEMA_NAME"],
+                            $database['SCHEMA_NAME'],
                             $replication_info[$type]['Do_DB']
                         );
 
diff --git a/libraries/classes/Controllers/Server/VariablesController.php b/libraries/classes/Controllers/Server/VariablesController.php
index 038bcfba62..115c498747 100644
--- a/libraries/classes/Controllers/Server/VariablesController.php
+++ b/libraries/classes/Controllers/Server/VariablesController.php
@@ -123,7 +123,7 @@ class VariablesController extends AbstractController
                     Util::formatByteDown($varValue[1], 3, 3)
                 );
             } else {
-                throw new KBException("Not a type=byte");
+                throw new KBException('Not a type=byte');
             }
         } catch (KBException $e) {
             $json['message'] = $varValue[1];
@@ -167,7 +167,7 @@ class VariablesController extends AbstractController
                     $exp[mb_strtolower($matches[3])]
                 );
             } else {
-                throw new KBException("Not a type=byte or regex not matching");
+                throw new KBException('Not a type=byte or regex not matching');
             }
         } catch (KBException $e) {
             $value = $this->dbi->escapeString($value);
@@ -178,7 +178,7 @@ class VariablesController extends AbstractController
         }
 
         $json = [];
-        if (! preg_match("/[^a-zA-Z0-9_]+/", $params['varName'])
+        if (! preg_match('/[^a-zA-Z0-9_]+/', $params['varName'])
             && $this->dbi->query(
                 'SET GLOBAL ' . $params['varName'] . ' = ' . $value
             )
@@ -236,7 +236,7 @@ class VariablesController extends AbstractController
                         )
                     );
                 } else {
-                    throw new KBException("Not a type=byte or regex not matching");
+                    throw new KBException('Not a type=byte or regex not matching');
                 }
             } catch (KBException $e) {
                 $formattedValue = Util::formatNumber($value, 0);
diff --git a/libraries/classes/Controllers/Setup/HomeController.php b/libraries/classes/Controllers/Setup/HomeController.php
index c5806023c9..17e7a053f6 100644
--- a/libraries/classes/Controllers/Setup/HomeController.php
+++ b/libraries/classes/Controllers/Setup/HomeController.php
@@ -137,7 +137,7 @@ class HomeController extends AbstractController
                 $servers[$id] = [
                     'id' => $id,
                     'name' => $this->config->getServerName($id),
-                    'auth_type' => $this->config->getValue("Servers/$id/auth_type"),
+                    'auth_type' => $this->config->getValue('Servers/' . $id . '/auth_type'),
                     'dsn' => $this->config->getServerDSN($id),
                     'params' => [
                         'token' => $_SESSION[' PMA_token '],
@@ -153,7 +153,7 @@ class HomeController extends AbstractController
                         ],
                     ],
                 ];
-                $serverDefaultOptions['values'][(string) $id] = $this->config->getServerName($id) . " [$id]";
+                $serverDefaultOptions['values'][(string) $id] = $this->config->getServerName($id) . ' [' . $id . ']';
             }
         } else {
             $serverDefaultOptions['values']['1'] = __('- none -');
diff --git a/libraries/classes/Controllers/Setup/ServersController.php b/libraries/classes/Controllers/Setup/ServersController.php
index 5d264765e6..8c659e1c24 100644
--- a/libraries/classes/Controllers/Setup/ServersController.php
+++ b/libraries/classes/Controllers/Setup/ServersController.php
@@ -27,7 +27,7 @@ class ServersController extends AbstractController
         $pages = $this->getPages();
 
         $id = Core::isValid($params['id'], 'numeric') ? (int) $params['id'] : null;
-        $hasServer = ! empty($id) && $this->config->get("Servers/$id") !== null;
+        $hasServer = ! empty($id) && $this->config->get('Servers/' . $id) !== null;
 
         if (! $hasServer && ($params['mode'] !== 'revert' && $params['mode'] !== 'edit')) {
             $id = 0;
@@ -56,7 +56,7 @@ class ServersController extends AbstractController
     {
         $id = Core::isValid($params['id'], 'numeric') ? (int) $params['id'] : null;
 
-        $hasServer = ! empty($id) && $this->config->get("Servers/$id") !== null;
+        $hasServer = ! empty($id) && $this->config->get('Servers/' . $id) !== null;
 
         if ($hasServer) {
             $this->config->removeServer($id);
diff --git a/libraries/classes/Controllers/Table/SearchController.php b/libraries/classes/Controllers/Table/SearchController.php
index d6e9f6fda7..3422a7e666 100644
--- a/libraries/classes/Controllers/Table/SearchController.php
+++ b/libraries/classes/Controllers/Table/SearchController.php
@@ -124,7 +124,7 @@ class SearchController extends AbstractController
         // Loads table's information
         $this->_loadTableInfo();
         $this->_connectionCharSet = $this->dbi->fetchValue(
-            "SELECT @@character_set_connection"
+            'SELECT @@character_set_connection'
         );
     }
 
@@ -164,10 +164,10 @@ class SearchController extends AbstractController
                 // strip the "BINARY" attribute, except if we find "BINARY(" because
                 // this would be a BINARY or VARBINARY column type
                 if (! preg_match('@BINARY[\(]@i', $type)) {
-                    $type = str_ireplace("BINARY", '', $type);
+                    $type = str_ireplace('BINARY', '', $type);
                 }
-                $type = str_ireplace("ZEROFILL", '', $type);
-                $type = str_ireplace("UNSIGNED", '', $type);
+                $type = str_ireplace('ZEROFILL', '', $type);
+                $type = str_ireplace('UNSIGNED', '', $type);
                 $type = mb_strtolower($type);
             }
             if (empty($type)) {
@@ -336,7 +336,7 @@ class SearchController extends AbstractController
 
         //Query execution part
         $result = $this->dbi->query(
-            $sql_query . ";",
+            $sql_query . ';',
             DatabaseInterface::CONNECT_USER,
             DatabaseInterface::QUERY_STORE
         );
@@ -447,7 +447,7 @@ class SearchController extends AbstractController
         $row_info_query = 'SELECT * FROM `' . $_POST['db'] . '`.`'
             . $_POST['table'] . '` WHERE ' . $_POST['where_clause'];
         $result = $this->dbi->query(
-            $row_info_query . ";",
+            $row_info_query . ';',
             DatabaseInterface::CONNECT_USER,
             DatabaseInterface::QUERY_STORE
         );
@@ -665,22 +665,22 @@ class SearchController extends AbstractController
                 $charSet
             );
         } else {
-            $sql_query = "SELECT "
-                . Util::backquote($column) . ","
-                . " REPLACE("
+            $sql_query = 'SELECT '
+                . Util::backquote($column) . ','
+                . ' REPLACE('
                 . Util::backquote($column) . ", '" . $find . "', '"
                 . $replaceWith
                 . "'),"
-                . " COUNT(*)"
-                . " FROM " . Util::backquote($this->db)
-                . "." . Util::backquote($this->table)
-                . " WHERE " . Util::backquote($column)
-                . " LIKE '%" . $find . "%' COLLATE " . $charSet . "_bin"; // here we
+                . ' COUNT(*)'
+                . ' FROM ' . Util::backquote($this->db)
+                . '.' . Util::backquote($this->table)
+                . ' WHERE ' . Util::backquote($column)
+                . " LIKE '%" . $find . "%' COLLATE " . $charSet . '_bin'; // here we
             // change the collation of the 2nd operand to a case sensitive
             // binary collation to make sure that the comparison
             // is case sensitive
-            $sql_query .= " GROUP BY " . Util::backquote($column)
-                . " ORDER BY " . Util::backquote($column) . " ASC";
+            $sql_query .= ' GROUP BY ' . Util::backquote($column)
+                . ' ORDER BY ' . Util::backquote($column) . ' ASC';
 
             $result = $this->dbi->fetchResult($sql_query, 0);
         }
@@ -713,19 +713,19 @@ class SearchController extends AbstractController
         $charSet
     ) {
         $column = $this->_columnNames[$columnIndex];
-        $sql_query = "SELECT "
-            . Util::backquote($column) . ","
-            . " 1," // to add an extra column that will have replaced value
-            . " COUNT(*)"
-            . " FROM " . Util::backquote($this->db)
-            . "." . Util::backquote($this->table)
-            . " WHERE " . Util::backquote($column)
+        $sql_query = 'SELECT '
+            . Util::backquote($column) . ','
+            . ' 1,' // to add an extra column that will have replaced value
+            . ' COUNT(*)'
+            . ' FROM ' . Util::backquote($this->db)
+            . '.' . Util::backquote($this->table)
+            . ' WHERE ' . Util::backquote($column)
             . " RLIKE '" . $this->dbi->escapeString($find) . "' COLLATE "
-            . $charSet . "_bin"; // here we
+            . $charSet . '_bin'; // here we
         // change the collation of the 2nd operand to a case sensitive
         // binary collation to make sure that the comparison is case sensitive
-        $sql_query .= " GROUP BY " . Util::backquote($column)
-            . " ORDER BY " . Util::backquote($column) . " ASC";
+        $sql_query .= ' GROUP BY ' . Util::backquote($column)
+            . ' ORDER BY ' . Util::backquote($column) . ' ASC';
 
         $result = $this->dbi->fetchResult($sql_query, 0);
 
@@ -791,8 +791,8 @@ class SearchController extends AbstractController
                 $replaceWith,
                 $charSet
             );
-            $sql_query = "UPDATE " . Util::backquote($this->table)
-                . " SET " . Util::backquote($column) . " = CASE";
+            $sql_query = 'UPDATE ' . Util::backquote($this->table)
+                . ' SET ' . Util::backquote($column) . ' = CASE';
             if (is_array($toReplace)) {
                 foreach ($toReplace as $row) {
                     $sql_query .= "\n WHEN " . Util::backquote($column)
@@ -800,22 +800,22 @@ class SearchController extends AbstractController
                         . "' THEN '" . $this->dbi->escapeString($row[1]) . "'";
                 }
             }
-            $sql_query .= " END"
-                . " WHERE " . Util::backquote($column)
+            $sql_query .= ' END'
+                . ' WHERE ' . Util::backquote($column)
                 . " RLIKE '" . $this->dbi->escapeString($find) . "' COLLATE "
-                . $charSet . "_bin"; // here we
+                . $charSet . '_bin'; // here we
             // change the collation of the 2nd operand to a case sensitive
             // binary collation to make sure that the comparison
             // is case sensitive
         } else {
-            $sql_query = "UPDATE " . Util::backquote($this->table)
-                . " SET " . Util::backquote($column) . " ="
-                . " REPLACE("
+            $sql_query = 'UPDATE ' . Util::backquote($this->table)
+                . ' SET ' . Util::backquote($column) . ' ='
+                . ' REPLACE('
                 . Util::backquote($column) . ", '" . $find . "', '"
                 . $replaceWith
                 . "')"
-                . " WHERE " . Util::backquote($column)
-                . " LIKE '%" . $find . "%' COLLATE " . $charSet . "_bin"; // here we
+                . ' WHERE ' . Util::backquote($column)
+                . " LIKE '%" . $find . "%' COLLATE " . $charSet . '_bin'; // here we
             // change the collation of the 2nd operand to a case sensitive
             // binary collation to make sure that the comparison
             // is case sensitive
@@ -1101,8 +1101,8 @@ class SearchController extends AbstractController
         $geom_funcs = Util::getGISFunctions($types, true, false);
 
         // If the function takes multiple parameters
-        if (strpos($func_type, "IS NULL") !== false || strpos($func_type, "IS NOT NULL") !== false) {
-            return Util::backquote($names) . " " . $func_type;
+        if (strpos($func_type, 'IS NULL') !== false || strpos($func_type, 'IS NOT NULL') !== false) {
+            return Util::backquote($names) . ' ' . $func_type;
         } elseif ($geom_funcs[$geom_func]['params'] > 1) {
             // create gis data from the criteria input
             $gis_data = Util::createGISData($criteriaValues, $this->dbi->getVersion());
@@ -1125,9 +1125,9 @@ class SearchController extends AbstractController
         ) {
             // create gis data from the criteria input
             $gis_data = Util::createGISData($criteriaValues, $this->dbi->getVersion());
-            $where = $geom_function_applied . " " . $func_type . " " . $gis_data;
+            $where = $geom_function_applied . ' ' . $func_type . ' ' . $gis_data;
         } elseif (strlen($criteriaValues) > 0) {
-            $where = $geom_function_applied . " "
+            $where = $geom_function_applied . ' '
                 . $func_type . " '" . $criteriaValues . "'";
         }
         return $where;
diff --git a/libraries/classes/Controllers/Table/StructureController.php b/libraries/classes/Controllers/Table/StructureController.php
index 922a3dba4b..3df3a98c64 100644
--- a/libraries/classes/Controllers/Table/StructureController.php
+++ b/libraries/classes/Controllers/Table/StructureController.php
@@ -626,8 +626,8 @@ class StructureController extends AbstractController
         $partitionDetails['partition_count'] = '';
 
         if (! empty($stmt->partitionBy)) {
-            $openPos = strpos($stmt->partitionBy, "(");
-            $closePos = strrpos($stmt->partitionBy, ")");
+            $openPos = strpos($stmt->partitionBy, '(');
+            $closePos = strrpos($stmt->partitionBy, ')');
 
             $partitionDetails['partition_by']
                 = trim(substr($stmt->partitionBy, 0, $openPos));
@@ -646,8 +646,8 @@ class StructureController extends AbstractController
         $partitionDetails['subpartition_count'] = '';
 
         if (! empty($stmt->subpartitionBy)) {
-            $openPos = strpos($stmt->subpartitionBy, "(");
-            $closePos = strrpos($stmt->subpartitionBy, ")");
+            $openPos = strpos($stmt->subpartitionBy, '(');
+            $closePos = strrpos($stmt->subpartitionBy, ')');
 
             $partitionDetails['subpartition_by']
                 = trim(substr($stmt->subpartitionBy, 0, $openPos));
@@ -768,7 +768,7 @@ class StructureController extends AbstractController
      */
     protected function updatePartitioning()
     {
-        $sql_query = "ALTER TABLE " . Util::backquote($this->table) . " "
+        $sql_query = 'ALTER TABLE ' . Util::backquote($this->table) . ' '
             . $this->createAddField->getPartitionsDefinition();
 
         // Execute alter query
@@ -1176,7 +1176,7 @@ class StructureController extends AbstractController
 
             if ($changed) {
                 // Finally FLUSH the new privileges
-                $this->dbi->query("FLUSH PRIVILEGES;");
+                $this->dbi->query('FLUSH PRIVILEGES;');
             }
         }
 
@@ -1322,7 +1322,7 @@ class StructureController extends AbstractController
 
             $displayed_fields[$rownum] = new stdClass();
             $displayed_fields[$rownum]->text = $field['Field'];
-            $displayed_fields[$rownum]->icon = "";
+            $displayed_fields[$rownum]->icon = '';
             $row_comments[$rownum] = '';
 
             if (isset($comments_map[$field['Field']])) {
diff --git a/libraries/classes/Core.php b/libraries/classes/Core.php
index e169345bb1..56547e99c7 100644
--- a/libraries/classes/Core.php
+++ b/libraries/classes/Core.php
@@ -715,8 +715,8 @@ class Core
         $url = Url::getCommon($params);
         //strip off token and such sensitive information. Just keep url.
         $arr = parse_url($url);
-        parse_str($arr["query"], $vars);
-        $query = http_build_query(["url" => $vars["url"]]);
+        parse_str($arr['query'], $vars);
+        $query = http_build_query(['url' => $vars['url']]);
 
         if ($GLOBALS['PMA_Config'] !== null && $GLOBALS['PMA_Config']->get('is_setup')) {
             $url = '../url.php?' . $query;
@@ -754,7 +754,7 @@ class Core
                 return false;
             }
         }
-        $domain = $arr["host"];
+        $domain = $arr['host'];
         $domainWhiteList = [
             /* Include current domain */
             $_SERVER['SERVER_NAME'],
@@ -1214,7 +1214,7 @@ class Core
     public static function checkRequest(): void
     {
         if (isset($_REQUEST['GLOBALS']) || isset($_FILES['GLOBALS'])) {
-            self::fatalError(__("GLOBALS overwrite attempt"));
+            self::fatalError(__('GLOBALS overwrite attempt'));
         }
 
         /**
diff --git a/libraries/classes/CreateAddField.php b/libraries/classes/CreateAddField.php
index 0396c787ff..a08012262e 100644
--- a/libraries/classes/CreateAddField.php
+++ b/libraries/classes/CreateAddField.php
@@ -201,7 +201,7 @@ class CreateAddField
 
         $keyBlockSizes = $index['Key_block_size'];
         if (! empty($keyBlockSizes)) {
-            $sqlQuery .= " KEY_BLOCK_SIZE = "
+            $sqlQuery .= ' KEY_BLOCK_SIZE = '
                  . $this->dbi->escapeString($keyBlockSizes);
         }
 
@@ -216,7 +216,7 @@ class CreateAddField
 
         $parser = $index['Parser'];
         if ($index['Index_choice'] == 'FULLTEXT' && ! empty($parser)) {
-            $sqlQuery .= " WITH PARSER " . $this->dbi->escapeString($parser);
+            $sqlQuery .= ' WITH PARSER ' . $this->dbi->escapeString($parser);
         }
 
         $comment = $index['Index_comment'];
@@ -240,7 +240,7 @@ class CreateAddField
      */
     private function getStatementPrefix(bool $isCreateTable = true): string
     {
-        $sqlPrefix = " ";
+        $sqlPrefix = ' ';
         if (! $isCreateTable) {
             $sqlPrefix = ' ADD ';
         }
@@ -267,7 +267,7 @@ class CreateAddField
         foreach ($indexedColumns as $index) {
             $statements = $this->buildIndexStatements(
                 $index,
-                " " . $indexKeyword . " ",
+                ' ' . $indexKeyword . ' ',
                 $isCreateTable
             );
             $definitions = array_merge($definitions, $statements);
@@ -286,7 +286,7 @@ class CreateAddField
      */
     private function getColumnCreationStatements(bool $isCreateTable = true): string
     {
-        $sqlStatement = "";
+        $sqlStatement = '';
         [
             $fieldCount,
             $fieldPrimary,
@@ -303,7 +303,7 @@ class CreateAddField
         // Builds the PRIMARY KEY statements
         $primaryKeyStatements = $this->buildIndexStatements(
             isset($fieldPrimary[0]) ? $fieldPrimary[0] : [],
-            " PRIMARY KEY ",
+            ' PRIMARY KEY ',
             $isCreateTable
         );
         $definitions = array_merge($definitions, $primaryKeyStatements);
@@ -313,7 +313,7 @@ class CreateAddField
             $definitions,
             $isCreateTable,
             $fieldIndex,
-            "INDEX"
+            'INDEX'
         );
 
         // Builds the UNIQUE statements
@@ -321,7 +321,7 @@ class CreateAddField
             $definitions,
             $isCreateTable,
             $fieldUnique,
-            "UNIQUE"
+            'UNIQUE'
         );
 
         // Builds the FULLTEXT statements
@@ -329,7 +329,7 @@ class CreateAddField
             $definitions,
             $isCreateTable,
             $fieldFullText,
-            "FULLTEXT"
+            'FULLTEXT'
         );
 
         // Builds the SPATIAL statements
@@ -337,7 +337,7 @@ class CreateAddField
             $definitions,
             $isCreateTable,
             $fieldSpatial,
-            "SPATIAL"
+            'SPATIAL'
         );
 
         if (count($definitions)) {
@@ -353,15 +353,15 @@ class CreateAddField
      */
     public function getPartitionsDefinition(): string
     {
-        $sqlQuery = "";
+        $sqlQuery = '';
         if (! empty($_POST['partition_by'])
             && ! empty($_POST['partition_expr'])
             && ! empty($_POST['partition_count'])
             && $_POST['partition_count'] > 1
         ) {
-            $sqlQuery .= " PARTITION BY " . $_POST['partition_by']
-                . " (" . $_POST['partition_expr'] . ")"
-                . " PARTITIONS " . $_POST['partition_count'];
+            $sqlQuery .= ' PARTITION BY ' . $_POST['partition_by']
+                . ' (' . $_POST['partition_expr'] . ')'
+                . ' PARTITIONS ' . $_POST['partition_count'];
         }
 
         if (! empty($_POST['subpartition_by'])
@@ -369,9 +369,9 @@ class CreateAddField
             && ! empty($_POST['subpartition_count'])
             && $_POST['subpartition_count'] > 1
         ) {
-            $sqlQuery .= " SUBPARTITION BY " . $_POST['subpartition_by']
-               . " (" . $_POST['subpartition_expr'] . ")"
-               . " SUBPARTITIONS " . $_POST['subpartition_count'];
+            $sqlQuery .= ' SUBPARTITION BY ' . $_POST['subpartition_by']
+               . ' (' . $_POST['subpartition_expr'] . ')'
+               . ' SUBPARTITIONS ' . $_POST['subpartition_count'];
         }
 
         if (! empty($_POST['partitions'])) {
@@ -379,7 +379,7 @@ class CreateAddField
             foreach ($_POST['partitions'] as $partition) {
                 $partitions[] = $this->getPartitionDefinition($partition);
             }
-            $sqlQuery .= " (" . implode(", ", $partitions) . ")";
+            $sqlQuery .= ' (' . implode(', ', $partitions) . ')';
         }
 
         return $sqlQuery;
@@ -397,19 +397,19 @@ class CreateAddField
         array $partition,
         bool $isSubPartition = false
     ): string {
-        $sqlQuery = " " . ($isSubPartition ? "SUB" : "") . "PARTITION ";
+        $sqlQuery = ' ' . ($isSubPartition ? 'SUB' : '') . 'PARTITION ';
         $sqlQuery .= $partition['name'];
 
         if (! empty($partition['value_type'])) {
-            $sqlQuery .= " VALUES " . $partition['value_type'];
+            $sqlQuery .= ' VALUES ' . $partition['value_type'];
 
             if ($partition['value_type'] != 'LESS THAN MAXVALUE') {
-                $sqlQuery .= " (" . $partition['value'] . ")";
+                $sqlQuery .= ' (' . $partition['value'] . ')';
             }
         }
 
         if (! empty($partition['engine'])) {
-            $sqlQuery .= " ENGINE = " . $partition['engine'];
+            $sqlQuery .= ' ENGINE = ' . $partition['engine'];
         }
         if (! empty($partition['comment'])) {
             $sqlQuery .= " COMMENT = '" . $partition['comment'] . "'";
@@ -421,16 +421,16 @@ class CreateAddField
             $sqlQuery .= " INDEX_DIRECTORY = '" . $partition['index_directory'] . "'";
         }
         if (! empty($partition['max_rows'])) {
-            $sqlQuery .= " MAX_ROWS = " . $partition['max_rows'];
+            $sqlQuery .= ' MAX_ROWS = ' . $partition['max_rows'];
         }
         if (! empty($partition['min_rows'])) {
-            $sqlQuery .= " MIN_ROWS = " . $partition['min_rows'];
+            $sqlQuery .= ' MIN_ROWS = ' . $partition['min_rows'];
         }
         if (! empty($partition['tablespace'])) {
-            $sqlQuery .= " TABLESPACE = " . $partition['tablespace'];
+            $sqlQuery .= ' TABLESPACE = ' . $partition['tablespace'];
         }
         if (! empty($partition['node_group'])) {
-            $sqlQuery .= " NODEGROUP = " . $partition['node_group'];
+            $sqlQuery .= ' NODEGROUP = ' . $partition['node_group'];
         }
 
         if (! empty($partition['subpartitions'])) {
@@ -441,7 +441,7 @@ class CreateAddField
                     true
                 );
             }
-            $sqlQuery .= " (" . implode(", ", $subpartitions) . ")";
+            $sqlQuery .= ' (' . implode(', ', $subpartitions) . ')';
         }
 
         return $sqlQuery;
diff --git a/libraries/classes/Database/Designer.php b/libraries/classes/Database/Designer.php
index 4208136cd1..906bda11fb 100644
--- a/libraries/classes/Database/Designer.php
+++ b/libraries/classes/Database/Designer.php
@@ -105,11 +105,11 @@ class Designer
             return $result;
         }
 
-        $page_query = "SELECT `page_nr`, `page_descr` FROM "
-            . Util::backquote($cfgRelation['db']) . "."
+        $page_query = 'SELECT `page_nr`, `page_descr` FROM '
+            . Util::backquote($cfgRelation['db']) . '.'
             . Util::backquote($cfgRelation['pdf_pages'])
             . " WHERE db_name = '" . $this->dbi->escapeString($db) . "'"
-            . " ORDER BY `page_descr`";
+            . ' ORDER BY `page_descr`';
         $page_rs = $this->relation->queryAsControlUser(
             $page_query,
             false,
@@ -135,7 +135,7 @@ class Designer
         /* Scan for schema plugins */
         /** @var SchemaPlugin[] $export_list */
         $export_list = Plugins::getPlugins(
-            "schema",
+            'schema',
             'libraries/classes/Plugins/Schema/',
             null
         );
diff --git a/libraries/classes/Database/Designer/Common.php b/libraries/classes/Database/Designer/Common.php
index ffaf519545..6d101674cd 100644
--- a/libraries/classes/Database/Designer/Common.php
+++ b/libraries/classes/Database/Designer/Common.php
@@ -127,7 +127,7 @@ class Common
     {
         $this->dbi->selectDb($GLOBALS['db']);
         $con = [];
-        $con["C_NAME"] = [];
+        $con['C_NAME'] = [];
         $i = 0;
         $alltab_rs = $this->dbi->query(
             'SHOW TABLES FROM ' . Util::backquote($GLOBALS['db']),
@@ -140,10 +140,10 @@ class Common
             if ($row !== false) {
                 foreach ($row as $field => $value) {
                     $con['C_NAME'][$i] = '';
-                    $con['DTN'][$i]    = rawurlencode($GLOBALS['db'] . "." . $val[0]);
+                    $con['DTN'][$i]    = rawurlencode($GLOBALS['db'] . '.' . $val[0]);
                     $con['DCN'][$i]    = rawurlencode($field);
                     $con['STN'][$i]    = rawurlencode(
-                        $value['foreign_db'] . "." . $value['foreign_table']
+                        $value['foreign_db'] . '.' . $value['foreign_table']
                     );
                     $con['SCN'][$i]    = rawurlencode($value['foreign_field']);
                     $i++;
@@ -156,12 +156,12 @@ class Common
                 foreach ($row['foreign_keys_data'] as $one_key) {
                     foreach ($one_key['index_list'] as $index => $one_field) {
                         $con['C_NAME'][$i] = rawurlencode($one_key['constraint']);
-                        $con['DTN'][$i]    = rawurlencode($GLOBALS['db'] . "." . $val[0]);
+                        $con['DTN'][$i]    = rawurlencode($GLOBALS['db'] . '.' . $val[0]);
                         $con['DCN'][$i]    = rawurlencode($one_field);
                         $con['STN'][$i]    = rawurlencode(
                             (isset($one_key['ref_db_name']) ?
                                 $one_key['ref_db_name'] : $GLOBALS['db'])
-                            . "." . $one_key['ref_table_name']
+                            . '.' . $one_key['ref_table_name']
                         );
                         $con['SCN'][$i] = rawurlencode($one_key['ref_index_list'][$index]);
                         $i++;
@@ -177,7 +177,7 @@ class Common
 
         $ti = 0;
         $retval = [];
-        for ($i = 0, $cnt = count($con["C_NAME"]); $i < $cnt; $i++) {
+        for ($i = 0, $cnt = count($con['C_NAME']); $i < $cnt; $i++) {
             $c_name_i = $con['C_NAME'][$i];
             $dtn_i = $con['DTN'][$i];
             $retval[$ti] = [];
@@ -277,8 +277,8 @@ class Common
                 1 AS `V`,
                 1 AS `H`
             FROM " . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['table_coords']) . "
-            WHERE pdf_page_number = " . intval($pg);
+                . '.' . Util::backquote($cfgRelation['table_coords']) . '
+            WHERE pdf_page_number = ' . intval($pg);
 
         return $this->dbi->fetchResult(
             $query,
@@ -303,10 +303,10 @@ class Common
             return null;
         }
 
-        $query = "SELECT `page_descr`"
-            . " FROM " . Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['pdf_pages'])
-            . " WHERE " . Util::backquote('page_nr') . " = " . intval($pg);
+        $query = 'SELECT `page_descr`'
+            . ' FROM ' . Util::backquote($cfgRelation['db'])
+            . '.' . Util::backquote($cfgRelation['pdf_pages'])
+            . ' WHERE ' . Util::backquote('page_nr') . ' = ' . intval($pg);
         $page_name = $this->dbi->fetchResult(
             $query,
             null,
@@ -331,9 +331,9 @@ class Common
             return false;
         }
 
-        $query = "DELETE FROM " . Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['table_coords'])
-            . " WHERE " . Util::backquote('pdf_page_number') . " = " . intval($pg);
+        $query = 'DELETE FROM ' . Util::backquote($cfgRelation['db'])
+            . '.' . Util::backquote($cfgRelation['table_coords'])
+            . ' WHERE ' . Util::backquote('pdf_page_number') . ' = ' . intval($pg);
         $success = $this->relation->queryAsControlUser(
             $query,
             true,
@@ -341,9 +341,9 @@ class Common
         );
 
         if ($success) {
-            $query = "DELETE FROM " . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['pdf_pages'])
-                . " WHERE " . Util::backquote('page_nr') . " = " . intval($pg);
+            $query = 'DELETE FROM ' . Util::backquote($cfgRelation['db'])
+                . '.' . Util::backquote($cfgRelation['pdf_pages'])
+                . ' WHERE ' . Util::backquote('page_nr') . ' = ' . intval($pg);
             $success = $this->relation->queryAsControlUser(
                 $query,
                 true,
@@ -369,9 +369,9 @@ class Common
             return -1;
         }
 
-        $query = "SELECT `page_nr`"
-            . " FROM " . Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['pdf_pages'])
+        $query = 'SELECT `page_nr`'
+            . ' FROM ' . Util::backquote($cfgRelation['db'])
+            . '.' . Util::backquote($cfgRelation['pdf_pages'])
             . " WHERE `db_name` = '" . $this->dbi->escapeString($db) . "'"
             . " AND `page_descr` = '" . $this->dbi->escapeString($db) . "'";
 
@@ -410,9 +410,9 @@ class Common
         if ($default_page_no != -1) {
             $page_no = $default_page_no;
         } else {
-            $query = "SELECT MIN(`page_nr`)"
-                . " FROM " . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['pdf_pages'])
+            $query = 'SELECT MIN(`page_nr`)'
+                . ' FROM ' . Util::backquote($cfgRelation['db'])
+                . '.' . Util::backquote($cfgRelation['pdf_pages'])
                 . " WHERE `db_name` = '" . $this->dbi->escapeString($db) . "'";
 
             $min_page_no = $this->dbi->fetchResult(
@@ -466,9 +466,9 @@ class Common
             return false;
         }
 
-        $query =  "DELETE FROM "
+        $query =  'DELETE FROM '
             . Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote(
+            . '.' . Util::backquote(
                 $cfgRelation['table_coords']
             )
             . " WHERE `pdf_page_number` = '" . $pageId . "'";
@@ -490,11 +490,11 @@ class Common
                 continue;
             }
 
-            $query = "INSERT INTO "
-                . Util::backquote($cfgRelation['db']) . "."
+            $query = 'INSERT INTO '
+                . Util::backquote($cfgRelation['db']) . '.'
                 . Util::backquote($cfgRelation['table_coords'])
-                . " (`db_name`, `table_name`, `pdf_page_number`, `x`, `y`)"
-                . " VALUES ("
+                . ' (`db_name`, `table_name`, `pdf_page_number`, `x`, `y`)'
+                . ' VALUES ('
                 . "'" . $this->dbi->escapeString($DB) . "', "
                 . "'" . $this->dbi->escapeString($TAB) . "', "
                 . "'" . $pageId . "', "
@@ -634,7 +634,7 @@ class Common
                 return [
                     false,
                     __('Error: FOREIGN KEY relationship could not be added!')
-                    . "<br>" . $error,
+                    . '<br>' . $error,
                 ];
             }
 
@@ -655,13 +655,13 @@ class Common
         // no need to recheck if the keys are primary or unique at this point,
         // this was checked on the interface part
 
-        $q  = "INSERT INTO "
+        $q  = 'INSERT INTO '
             . Util::backquote($GLOBALS['cfgRelation']['db'])
-            . "."
+            . '.'
             . Util::backquote($GLOBALS['cfgRelation']['relation'])
-            . "(master_db, master_table, master_field, "
-            . "foreign_db, foreign_table, foreign_field)"
-            . " values("
+            . '(master_db, master_table, master_field, '
+            . 'foreign_db, foreign_table, foreign_field)'
+            . ' values('
             . "'" . $this->dbi->escapeString($DB2) . "', "
             . "'" . $this->dbi->escapeString($T2) . "', "
             . "'" . $this->dbi->escapeString($F2) . "', "
@@ -681,7 +681,7 @@ class Common
         return [
             false,
             __('Error: Internal relationship could not be added!')
-            . "<br>" . $error,
+            . '<br>' . $error,
         ];
     }
 
@@ -697,8 +697,8 @@ class Common
      */
     public function removeRelation($T1, $F1, $T2, $F2)
     {
-        list($DB1, $T1) = explode(".", $T1);
-        list($DB2, $T2) = explode(".", $T2);
+        list($DB1, $T1) = explode('.', $T1);
+        list($DB2, $T2) = explode('.', $T2);
 
         $tables = $this->dbi->getTablesFull($DB1, $T1);
         $type_T1 = mb_strtoupper($tables[$T1]['ENGINE']);
@@ -728,15 +728,15 @@ class Common
                 return [
                     false,
                     __('Error: FOREIGN KEY relationship could not be removed!')
-                    . "<br>" . $error,
+                    . '<br>' . $error,
                 ];
             }
         }
 
         // internal relations
-        $delete_query = "DELETE FROM "
-            . Util::backquote($GLOBALS['cfgRelation']['db']) . "."
-            . $GLOBALS['cfgRelation']['relation'] . " WHERE "
+        $delete_query = 'DELETE FROM '
+            . Util::backquote($GLOBALS['cfgRelation']['db']) . '.'
+            . $GLOBALS['cfgRelation']['relation'] . ' WHERE '
             . "master_db = '" . $this->dbi->escapeString($DB2) . "'"
             . " AND master_table = '" . $this->dbi->escapeString($T2) . "'"
             . " AND master_field = '" . $this->dbi->escapeString($F2) . "'"
@@ -754,7 +754,7 @@ class Common
             $error = $this->dbi->getError(DatabaseInterface::CONNECT_CONTROL);
             return [
                 false,
-                __('Error: Internal relationship could not be removed!') . "<br>" . $error,
+                __('Error: Internal relationship could not be removed!') . '<br>' . $error,
             ];
         }
 
@@ -783,9 +783,9 @@ class Common
                 'table' => $cfgRelation['designer_settings'],
             ];
 
-            $orig_data_query = "SELECT settings_data"
-                . " FROM " . Util::backquote($cfgDesigner['db'])
-                . "." . Util::backquote($cfgDesigner['table'])
+            $orig_data_query = 'SELECT settings_data'
+                . ' FROM ' . Util::backquote($cfgDesigner['db'])
+                . '.' . Util::backquote($cfgDesigner['table'])
                 . " WHERE username = '"
                 . $this->dbi->escapeString($cfgDesigner['user']) . "';";
 
@@ -800,9 +800,9 @@ class Common
                 $orig_data[$index] = $value;
                 $orig_data = json_encode($orig_data);
 
-                $save_query = "UPDATE "
+                $save_query = 'UPDATE '
                     . Util::backquote($cfgDesigner['db'])
-                    . "." . Util::backquote($cfgDesigner['table'])
+                    . '.' . Util::backquote($cfgDesigner['table'])
                     . " SET settings_data = '" . $orig_data . "'"
                     . " WHERE username = '"
                     . $this->dbi->escapeString($cfgDesigner['user']) . "';";
@@ -811,10 +811,10 @@ class Common
             } else {
                 $save_data = [$index => $value];
 
-                $query = "INSERT INTO "
+                $query = 'INSERT INTO '
                     . Util::backquote($cfgDesigner['db'])
-                    . "." . Util::backquote($cfgDesigner['table'])
-                    . " (username, settings_data)"
+                    . '.' . Util::backquote($cfgDesigner['table'])
+                    . ' (username, settings_data)'
                     . " VALUES('" . $this->dbi->escapeString($cfgDesigner['user'])
                     . "', '" . json_encode($save_data) . "');";
 
diff --git a/libraries/classes/Database/Qbe.php b/libraries/classes/Database/Qbe.php
index 5bcc305d91..2f7e1e0aac 100644
--- a/libraries/classes/Database/Qbe.php
+++ b/libraries/classes/Database/Qbe.php
@@ -791,8 +791,8 @@ class Qbe
     private function _getTableFooters()
     {
         $html_output = '<fieldset class="tblFooters">';
-        $html_output .= $this->_getFootersOptions("row");
-        $html_output .= $this->_getFootersOptions("column");
+        $html_output .= $this->_getFootersOptions('row');
+        $html_output .= $this->_getFootersOptions('column');
         $html_output .= '<div class="floatleft">';
         $html_output .= '<input class="btn btn-secondary" type="submit" name="modify"'
             . ' value="' . __('Update Query') . '">';
@@ -1099,7 +1099,7 @@ class Qbe
             ) {
                 $select = $this->_formColumns[$column_index];
                 if (! empty($this->_formAliases[$column_index])) {
-                    $select .= " AS "
+                    $select .= ' AS '
                         . Util::backquote($this->_formAliases[$column_index]);
                 }
                 $select_clauses[] = $select;
@@ -1107,7 +1107,7 @@ class Qbe
         } // end for
         if (! empty($select_clauses)) {
             $select_clause = 'SELECT '
-                . htmlspecialchars(implode(", ", $select_clauses)) . "\n";
+                . htmlspecialchars(implode(', ', $select_clauses)) . "\n";
         }
         return $select_clause;
     }
@@ -1236,7 +1236,7 @@ class Qbe
         } // end for
         if (! empty($orderby_clauses)) {
             $orderby_clause = 'ORDER BY '
-                . htmlspecialchars(implode(", ", $orderby_clauses)) . "\n";
+                . htmlspecialchars(implode(', ', $orderby_clauses)) . "\n";
         }
         return $orderby_clause;
     }
@@ -1635,14 +1635,14 @@ class Qbe
         foreach ($finalized as $table => $clause) {
             if ($first) {
                 if (! empty($join)) {
-                    $join .= ", ";
+                    $join .= ', ';
                 }
                 $join .= Util::backquote($table);
                 $first = false;
             } else {
                 $join .= "\n    LEFT JOIN " . Util::backquote(
                     $table
-                ) . " ON " . $clause;
+                ) . ' ON ' . $clause;
             }
         }
 
@@ -1670,20 +1670,20 @@ class Qbe
                     // There may be multiple column relations
                     foreach ($oneKey['index_list'] as $index => $oneField) {
                         $clauses[]
-                            = Util::backquote($oneTable) . "."
-                            . Util::backquote($oneField) . " = "
-                            . Util::backquote($oneKey['ref_table_name']) . "."
+                            = Util::backquote($oneTable) . '.'
+                            . Util::backquote($oneField) . ' = '
+                            . Util::backquote($oneKey['ref_table_name']) . '.'
                             . Util::backquote($oneKey['ref_index_list'][$index]);
                     }
                     // Combine multiple column relations with AND
                     $relations[$oneTable][$oneKey['ref_table_name']]
-                        = implode(" AND ", $clauses);
+                        = implode(' AND ', $clauses);
                 }
             } else { // Internal relations
                 $relations[$oneTable][$foreigner['foreign_table']]
-                    = Util::backquote($oneTable) . "."
-                    . Util::backquote($field) . " = "
-                    . Util::backquote($foreigner['foreign_table']) . "."
+                    = Util::backquote($oneTable) . '.'
+                    . Util::backquote($field) . ' = '
+                    . Util::backquote($foreigner['foreign_table']) . '.'
                     . Util::backquote($foreigner['foreign_field']);
             }
         }
diff --git a/libraries/classes/DatabaseInterface.php b/libraries/classes/DatabaseInterface.php
index 4ffca7a6f2..89d2b97a48 100644
--- a/libraries/classes/DatabaseInterface.php
+++ b/libraries/classes/DatabaseInterface.php
@@ -410,16 +410,16 @@ class DatabaseInterface
         $tablesListForQuery = rtrim($tablesListForQuery, ',');
 
         $foreignKeyConstrains = $this->fetchResult(
-            "SELECT"
-                    . " TABLE_NAME,"
-                    . " COLUMN_NAME,"
-                    . " REFERENCED_TABLE_NAME,"
-                    . " REFERENCED_COLUMN_NAME"
-                . " FROM information_schema.key_column_usage"
-                . " WHERE referenced_table_name IS NOT NULL"
+            'SELECT'
+                    . ' TABLE_NAME,'
+                    . ' COLUMN_NAME,'
+                    . ' REFERENCED_TABLE_NAME,'
+                    . ' REFERENCED_COLUMN_NAME'
+                . ' FROM information_schema.key_column_usage'
+                . ' WHERE referenced_table_name IS NOT NULL'
                     . " AND TABLE_SCHEMA = '" . $this->escapeString($database) . "'"
-                    . " AND TABLE_NAME IN (" . $tablesListForQuery . ")"
-                    . " AND REFERENCED_TABLE_NAME IN (" . $tablesListForQuery . ");",
+                    . ' AND TABLE_NAME IN (' . $tablesListForQuery . ')'
+                    . ' AND REFERENCED_TABLE_NAME IN (' . $tablesListForQuery . ');',
             null,
             null,
             $link,
@@ -594,7 +594,7 @@ class DatabaseInterface
             $sql = $this->_getSqlForTablesFull($this_databases, $sql_where_table);
 
             // Sort the tables
-            $sql .= " ORDER BY $sort_by $sort_order";
+            $sql .= ' ORDER BY ' . $sort_by . ' ' . $sort_order;
 
             if ($limit_count) {
                 $sql .= ' LIMIT ' . $limit_count . ' OFFSET ' . $limit_offset;
@@ -675,7 +675,7 @@ class DatabaseInterface
                     }
                     if (! empty($table_type)) {
                         if ($needAnd) {
-                            $sql .= " AND";
+                            $sql .= ' AND';
                         }
                         if ($table_type == 'view') {
                             $sql .= " `Comment` = 'VIEW'";
@@ -1478,7 +1478,7 @@ class DatabaseInterface
             return true;
         }
 
-        return $this->query("SET " . $var . " = " . $value . ';', $link);
+        return $this->query('SET ' . $var . ' = ' . $value . ';', $link);
     }
 
     /**
@@ -1531,7 +1531,7 @@ class DatabaseInterface
         $GLOBALS['collation_connection'] = $default_collation;
         $GLOBALS['charset_connection'] = $default_charset;
         $this->query(
-            "SET NAMES '$default_charset' COLLATE '$default_collation';",
+            sprintf('SET NAMES \'%s\' COLLATE \'%s\';', $default_charset, $default_collation),
             DatabaseInterface::CONNECT_USER,
             self::QUERY_STORE
         );
@@ -2006,27 +2006,27 @@ class DatabaseInterface
     ): array {
         $routines = [];
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
-            $query = "SELECT"
-                . " `ROUTINE_SCHEMA` AS `Db`,"
-                . " `SPECIFIC_NAME` AS `Name`,"
-                . " `ROUTINE_TYPE` AS `Type`,"
-                . " `DEFINER` AS `Definer`,"
-                . " `LAST_ALTERED` AS `Modified`,"
-                . " `CREATED` AS `Created`,"
-                . " `SECURITY_TYPE` AS `Security_type`,"
-                . " `ROUTINE_COMMENT` AS `Comment`,"
-                . " `CHARACTER_SET_CLIENT` AS `character_set_client`,"
-                . " `COLLATION_CONNECTION` AS `collation_connection`,"
-                . " `DATABASE_COLLATION` AS `Database Collation`,"
-                . " `DTD_IDENTIFIER`"
-                . " FROM `information_schema`.`ROUTINES`"
-                . " WHERE `ROUTINE_SCHEMA` " . Util::getCollateForIS()
+            $query = 'SELECT'
+                . ' `ROUTINE_SCHEMA` AS `Db`,'
+                . ' `SPECIFIC_NAME` AS `Name`,'
+                . ' `ROUTINE_TYPE` AS `Type`,'
+                . ' `DEFINER` AS `Definer`,'
+                . ' `LAST_ALTERED` AS `Modified`,'
+                . ' `CREATED` AS `Created`,'
+                . ' `SECURITY_TYPE` AS `Security_type`,'
+                . ' `ROUTINE_COMMENT` AS `Comment`,'
+                . ' `CHARACTER_SET_CLIENT` AS `character_set_client`,'
+                . ' `COLLATION_CONNECTION` AS `collation_connection`,'
+                . ' `DATABASE_COLLATION` AS `Database Collation`,'
+                . ' `DTD_IDENTIFIER`'
+                . ' FROM `information_schema`.`ROUTINES`'
+                . ' WHERE `ROUTINE_SCHEMA` ' . Util::getCollateForIS()
                 . " = '" . $this->escapeString($db) . "'";
             if (Core::isValid($which, ['FUNCTION', 'PROCEDURE'])) {
                 $query .= " AND `ROUTINE_TYPE` = '" . $which . "'";
             }
             if (! empty($name)) {
-                $query .= " AND `SPECIFIC_NAME`"
+                $query .= ' AND `SPECIFIC_NAME`'
                     . " = '" . $this->escapeString($name) . "'";
             }
             $result = $this->fetchResult($query);
@@ -2035,7 +2035,7 @@ class DatabaseInterface
             }
         } else {
             if ($which == 'FUNCTION' || $which == null) {
-                $query = "SHOW FUNCTION STATUS"
+                $query = 'SHOW FUNCTION STATUS'
                     . " WHERE `Db` = '" . $this->escapeString($db) . "'";
                 if (! empty($name)) {
                     $query .= " AND `Name` = '"
@@ -2047,7 +2047,7 @@ class DatabaseInterface
                 }
             }
             if ($which == 'PROCEDURE' || $which == null) {
-                $query = "SHOW PROCEDURE STATUS"
+                $query = 'SHOW PROCEDURE STATUS'
                     . " WHERE `Db` = '" . $this->escapeString($db) . "'";
                 if (! empty($name)) {
                     $query .= " AND `Name` = '"
@@ -2068,7 +2068,7 @@ class DatabaseInterface
             $one_result['type'] = $routine['Type'];
             $one_result['definer'] = $routine['Definer'];
             $one_result['returns'] = isset($routine['DTD_IDENTIFIER'])
-                ? $routine['DTD_IDENTIFIER'] : "";
+                ? $routine['DTD_IDENTIFIER'] : '';
             $ret[] = $one_result;
         }
 
@@ -2093,31 +2093,31 @@ class DatabaseInterface
     public function getEvents(string $db, string $name = ''): array
     {
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
-            $query = "SELECT"
-                . " `EVENT_SCHEMA` AS `Db`,"
-                . " `EVENT_NAME` AS `Name`,"
-                . " `DEFINER` AS `Definer`,"
-                . " `TIME_ZONE` AS `Time zone`,"
-                . " `EVENT_TYPE` AS `Type`,"
-                . " `EXECUTE_AT` AS `Execute at`,"
-                . " `INTERVAL_VALUE` AS `Interval value`,"
-                . " `INTERVAL_FIELD` AS `Interval field`,"
-                . " `STARTS` AS `Starts`,"
-                . " `ENDS` AS `Ends`,"
-                . " `STATUS` AS `Status`,"
-                . " `ORIGINATOR` AS `Originator`,"
-                . " `CHARACTER_SET_CLIENT` AS `character_set_client`,"
-                . " `COLLATION_CONNECTION` AS `collation_connection`, "
-                . "`DATABASE_COLLATION` AS `Database Collation`"
-                . " FROM `information_schema`.`EVENTS`"
-                . " WHERE `EVENT_SCHEMA` " . Util::getCollateForIS()
+            $query = 'SELECT'
+                . ' `EVENT_SCHEMA` AS `Db`,'
+                . ' `EVENT_NAME` AS `Name`,'
+                . ' `DEFINER` AS `Definer`,'
+                . ' `TIME_ZONE` AS `Time zone`,'
+                . ' `EVENT_TYPE` AS `Type`,'
+                . ' `EXECUTE_AT` AS `Execute at`,'
+                . ' `INTERVAL_VALUE` AS `Interval value`,'
+                . ' `INTERVAL_FIELD` AS `Interval field`,'
+                . ' `STARTS` AS `Starts`,'
+                . ' `ENDS` AS `Ends`,'
+                . ' `STATUS` AS `Status`,'
+                . ' `ORIGINATOR` AS `Originator`,'
+                . ' `CHARACTER_SET_CLIENT` AS `character_set_client`,'
+                . ' `COLLATION_CONNECTION` AS `collation_connection`, '
+                . '`DATABASE_COLLATION` AS `Database Collation`'
+                . ' FROM `information_schema`.`EVENTS`'
+                . ' WHERE `EVENT_SCHEMA` ' . Util::getCollateForIS()
                 . " = '" . $this->escapeString($db) . "'";
             if (! empty($name)) {
-                $query .= " AND `EVENT_NAME`"
+                $query .= ' AND `EVENT_NAME`'
                     . " = '" . $this->escapeString($name) . "'";
             }
         } else {
-            $query = "SHOW EVENTS FROM " . Util::backquote($db);
+            $query = 'SHOW EVENTS FROM ' . Util::backquote($db);
             if (! empty($name)) {
                 $query .= " AND `Name` = '"
                     . $this->escapeString($name) . "'";
@@ -2166,11 +2166,11 @@ class DatabaseInterface
                 . ' \'' . $this->escapeString($db) . '\'';
 
             if (! empty($table)) {
-                $query .= " AND EVENT_OBJECT_TABLE " . Util::getCollateForIS()
+                $query .= ' AND EVENT_OBJECT_TABLE ' . Util::getCollateForIS()
                     . " = '" . $this->escapeString($table) . "';";
             }
         } else {
-            $query = "SHOW TRIGGERS FROM " . Util::backquote($db);
+            $query = 'SHOW TRIGGERS FROM ' . Util::backquote($db);
             if (! empty($table)) {
                 $query .= " LIKE '" . $this->escapeString($table) . "';";
             }
@@ -2340,20 +2340,20 @@ class DatabaseInterface
                 $query = 'SELECT 1 FROM mysql.user LIMIT 1';
             } elseif ($type === 'create') {
                 [$user, $host] = $this->getCurrentUserAndHost();
-                $query = "SELECT 1 FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES` "
+                $query = 'SELECT 1 FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES` '
                     . "WHERE `PRIVILEGE_TYPE` = 'CREATE USER' AND "
                     . "'''" . $user . "''@''" . $host . "''' LIKE `GRANTEE` LIMIT 1";
             } elseif ($type === 'grant') {
                 [$user, $host] = $this->getCurrentUserAndHost();
-                $query = "SELECT 1 FROM ("
-                    . "SELECT `GRANTEE`, `IS_GRANTABLE` FROM "
-                    . "`INFORMATION_SCHEMA`.`COLUMN_PRIVILEGES` UNION "
-                    . "SELECT `GRANTEE`, `IS_GRANTABLE` FROM "
-                    . "`INFORMATION_SCHEMA`.`TABLE_PRIVILEGES` UNION "
-                    . "SELECT `GRANTEE`, `IS_GRANTABLE` FROM "
-                    . "`INFORMATION_SCHEMA`.`SCHEMA_PRIVILEGES` UNION "
-                    . "SELECT `GRANTEE`, `IS_GRANTABLE` FROM "
-                    . "`INFORMATION_SCHEMA`.`USER_PRIVILEGES`) t "
+                $query = 'SELECT 1 FROM ('
+                    . 'SELECT `GRANTEE`, `IS_GRANTABLE` FROM '
+                    . '`INFORMATION_SCHEMA`.`COLUMN_PRIVILEGES` UNION '
+                    . 'SELECT `GRANTEE`, `IS_GRANTABLE` FROM '
+                    . '`INFORMATION_SCHEMA`.`TABLE_PRIVILEGES` UNION '
+                    . 'SELECT `GRANTEE`, `IS_GRANTABLE` FROM '
+                    . '`INFORMATION_SCHEMA`.`SCHEMA_PRIVILEGES` UNION '
+                    . 'SELECT `GRANTEE`, `IS_GRANTABLE` FROM '
+                    . '`INFORMATION_SCHEMA`.`USER_PRIVILEGES`) t '
                     . "WHERE `IS_GRANTABLE` = 'YES' AND "
                     . "'''" . $user . "''@''" . $host . "''' LIKE `GRANTEE` LIMIT 1";
             }
@@ -2371,7 +2371,7 @@ class DatabaseInterface
         } else {
             $is = false;
             $grants = $this->fetchResult(
-                "SHOW GRANTS FOR CURRENT_USER();",
+                'SHOW GRANTS FOR CURRENT_USER();',
                 null,
                 null,
                 self::CONNECT_USER,
@@ -2380,14 +2380,14 @@ class DatabaseInterface
             if ($grants) {
                 foreach ($grants as $grant) {
                     if ($type === 'create') {
-                        if (strpos($grant, "ALL PRIVILEGES ON *.*") !== false
-                            || strpos($grant, "CREATE USER") !== false
+                        if (strpos($grant, 'ALL PRIVILEGES ON *.*') !== false
+                            || strpos($grant, 'CREATE USER') !== false
                         ) {
                             $is = true;
                             break;
                         }
                     } elseif ($type === 'grant') {
-                        if (strpos($grant, "WITH GRANT OPTION") !== false) {
+                        if (strpos($grant, 'WITH GRANT OPTION') !== false) {
                             $is = true;
                             break;
                         }
@@ -2415,7 +2415,7 @@ class DatabaseInterface
                     '',
                 ];
             } else {
-                $this->_current_user = explode("@", $user);
+                $this->_current_user = explode('@', $user);
             }
         }
         return $this->_current_user;
@@ -2430,7 +2430,7 @@ class DatabaseInterface
     {
         if ($this->_lower_case_table_names === null) {
             $this->_lower_case_table_names = $this->fetchValue(
-                "SELECT @@lower_case_table_names"
+                'SELECT @@lower_case_table_names'
             );
         }
         return $this->_lower_case_table_names;
diff --git a/libraries/classes/Display/Export.php b/libraries/classes/Display/Export.php
index 3b601ee281..4142eec96a 100644
--- a/libraries/classes/Display/Export.php
+++ b/libraries/classes/Display/Export.php
@@ -78,7 +78,7 @@ class Export
         // (from clicking Back button on /export page)
         if (isset($_POST['db_select'])) {
             $_POST['db_select'] = urldecode($_POST['db_select']);
-            $_POST['db_select'] = explode(",", $_POST['db_select']);
+            $_POST['db_select'] = explode(',', $_POST['db_select']);
         }
 
         $databases = [];
@@ -166,13 +166,13 @@ class Export
         // Get the relation settings
         $cfgRelation = $this->relation->getRelationsParam();
 
-        $query = "SELECT `id`, `template_name` FROM "
+        $query = 'SELECT `id`, `template_name` FROM '
            . Util::backquote($cfgRelation['db']) . '.'
            . Util::backquote($cfgRelation['export_templates'])
-           . " WHERE `username` = "
+           . ' WHERE `username` = '
            . "'" . $GLOBALS['dbi']->escapeString($GLOBALS['cfg']['Server']['user'])
             . "' AND `export_type` = '" . $GLOBALS['dbi']->escapeString($exportType) . "'"
-           . " ORDER BY `template_name`;";
+           . ' ORDER BY `template_name`;';
 
         $result = $this->relation->queryAsControlUser($query);
 
@@ -689,7 +689,7 @@ class Export
         /* Scan for plugins */
         /** @var ExportPlugin[] $exportList */
         $exportList = Plugins::getPlugins(
-            "export",
+            'export',
             'libraries/classes/Plugins/Export/',
             [
                 'export_type' => $exportType,
@@ -767,10 +767,10 @@ class Export
 
         switch ($_POST['templateAction']) {
             case 'create':
-                $query = "INSERT INTO " . $templateTable . "("
-                . " `username`, `export_type`,"
-                . " `template_name`, `template_data`"
-                . ") VALUES ("
+                $query = 'INSERT INTO ' . $templateTable . '('
+                . ' `username`, `export_type`,'
+                . ' `template_name`, `template_data`'
+                . ') VALUES ('
                 . "'" . $user . "', "
                 . "'" . $GLOBALS['dbi']->escapeString($_POST['exportType'])
                 . "', '" . $GLOBALS['dbi']->escapeString($_POST['templateName'])
@@ -778,17 +778,17 @@ class Export
                 . "');";
                 break;
             case 'load':
-                $query = "SELECT `template_data` FROM " . $templateTable
-                 . " WHERE `id` = " . $id . " AND `username` = '" . $user . "'";
+                $query = 'SELECT `template_data` FROM ' . $templateTable
+                 . ' WHERE `id` = ' . $id . " AND `username` = '" . $user . "'";
                 break;
             case 'update':
-                $query = "UPDATE " . $templateTable . " SET `template_data` = "
+                $query = 'UPDATE ' . $templateTable . ' SET `template_data` = '
                   . "'" . $GLOBALS['dbi']->escapeString($_POST['templateData']) . "'"
-                  . " WHERE `id` = " . $id . " AND `username` = '" . $user . "'";
+                  . ' WHERE `id` = ' . $id . " AND `username` = '" . $user . "'";
                 break;
             case 'delete':
-                $query = "DELETE FROM " . $templateTable
-                   . " WHERE `id` = " . $id . " AND `username` = '" . $user . "'";
+                $query = 'DELETE FROM ' . $templateTable
+                   . ' WHERE `id` = ' . $id . " AND `username` = '" . $user . "'";
                 break;
             default:
                 $query = '';
diff --git a/libraries/classes/Display/Import.php b/libraries/classes/Display/Import.php
index af1ad4baa9..c76d22f3b1 100644
--- a/libraries/classes/Display/Import.php
+++ b/libraries/classes/Display/Import.php
@@ -50,7 +50,7 @@ class Import
         /* Scan for plugins */
         /** @var ImportPlugin[] $importList */
         $importList = Plugins::getPlugins(
-            "import",
+            'import',
             'libraries/classes/Plugins/Import/',
             $importType
         );
@@ -101,7 +101,7 @@ class Import
 
         return $template->render('display/import/import', [
             'upload_id' => $uploadId,
-            'handler' => $_SESSION[$SESSION_KEY]["handler"],
+            'handler' => $_SESSION[$SESSION_KEY]['handler'],
             'id_key' => $_SESSION[$SESSION_KEY]['handler']::getIdKey(),
             'pma_theme_image' => $GLOBALS['pmaThemeImage'],
             'import_type' => $importType,
diff --git a/libraries/classes/Display/ImportAjax.php b/libraries/classes/Display/ImportAjax.php
index 396b7009ef..9a66964734 100644
--- a/libraries/classes/Display/ImportAjax.php
+++ b/libraries/classes/Display/ImportAjax.php
@@ -32,12 +32,12 @@ class ImportAjax
         /**
          * sets default plugin for handling the import process
          */
-        $_SESSION[$SESSION_KEY]["handler"] = "";
+        $_SESSION[$SESSION_KEY]['handler'] = '';
 
         /**
          * unique ID for each upload
          */
-        $upload_id = uniqid("");
+        $upload_id = uniqid('');
 
         /**
          * list of available plugins
@@ -45,20 +45,20 @@ class ImportAjax
         $plugins = [
             // PHP 5.4 session-based upload progress is problematic, see bug 3964
             //"session",
-            "progress",
-            "apc",
-            "noplugin",
+            'progress',
+            'apc',
+            'noplugin',
         ];
 
         // select available plugin
         foreach ($plugins as $plugin) {
-            $check = $plugin . "Check";
+            $check = $plugin . 'Check';
 
             if (self::$check()) {
                 $upload_class = 'PhpMyAdmin\Plugins\Import\Upload\Upload' . ucwords(
                     $plugin
                 );
-                $_SESSION[$SESSION_KEY]["handler"] = $upload_class;
+                $_SESSION[$SESSION_KEY]['handler'] = $upload_class;
                 break;
             }
         }
@@ -95,7 +95,7 @@ class ImportAjax
      */
     public static function progressCheck()
     {
-        return function_exists("uploadprogress_get_info")
+        return function_exists('uploadprogress_get_info')
             && function_exists('getallheaders');
     }
 
diff --git a/libraries/classes/Display/Results.php b/libraries/classes/Display/Results.php
index 372368af72..bff2bb8354 100644
--- a/libraries/classes/Display/Results.php
+++ b/libraries/classes/Display/Results.php
@@ -1780,7 +1780,7 @@ class Results
         array $sort_direction,
         $fields_meta
     ) {
-        $sort_order = "";
+        $sort_order = '';
         // Check if the current column is in the order by clause
         $is_in_sort = $this->_isInSorted(
             $sort_expression,
@@ -1829,13 +1829,13 @@ class Results
 
             // If this the first column name in the order by clause add
             // order by clause to the  column name
-            $query_head = $is_first_clause ? "\nORDER BY " : "";
+            $query_head = $is_first_clause ? "\nORDER BY " : '';
             // Again a check to see if the given column is a aggregate column
             if (mb_strpos($name_to_use_in_sort, '(') !== false) {
                 $sort_order .=  $query_head . $name_to_use_in_sort . ' ' ;
             } else {
                 if (strlen($sort_tbl_new) > 0) {
-                    $sort_tbl_new .= ".";
+                    $sort_tbl_new .= '.';
                 }
                 $sort_order .=  $query_head . $sort_tbl_new
                   . Util::backquote(
@@ -1845,7 +1845,7 @@ class Results
 
             // For a special case where the code generates two dots between
             // column name and table name.
-            $sort_order = preg_replace("/\.\./", ".", $sort_order);
+            $sort_order = preg_replace('/\.\./', '.', $sort_order);
             // Incase this is the current column save $single_sort_order
             if ($current_name == $name_to_use_in_sort) {
                 if (mb_strpos($current_name, '(') !== false) {
@@ -1874,12 +1874,12 @@ class Results
                     $sort_order,
                     $index
                 );
-                $order_img .= " <small>" . ($index + 1) . "</small>";
+                $order_img .= ' <small>' . ($index + 1) . '</small>';
             } else {
                 $sort_order .= strtoupper($sort_direction[$index]);
             }
             // Separate columns by a comma
-            $sort_order .= ", ";
+            $sort_order .= ', ';
         }
         // remove the comma from the last column name in the newly
         // constructed clause
@@ -1924,7 +1924,7 @@ class Results
         foreach ($sort_expression_nodirection as $index => $clause) {
             if (mb_strpos($clause, '.') !== false) {
                 $fragments = explode('.', $clause);
-                $clause2 = $fragments[0] . "." . str_replace('`', '', $fragments[1]);
+                $clause2 = $fragments[0] . '.' . str_replace('`', '', $fragments[1]);
             } else {
                 $clause2 = $sort_tbl . str_replace('`', '', $clause);
             }
@@ -1999,7 +1999,7 @@ class Results
                     's_desc',
                     __('Descending'),
                     [
-                        'class' => "soimg",
+                        'class' => 'soimg',
                         'title' => '',
                     ]
                 );
@@ -2007,7 +2007,7 @@ class Results
                     's_asc',
                     __('Ascending'),
                     [
-                        'class' => "soimg hide",
+                        'class' => 'soimg hide',
                         'title' => '',
                     ]
                 );
@@ -2017,7 +2017,7 @@ class Results
                     's_asc',
                     __('Ascending'),
                     [
-                        'class' => "soimg",
+                        'class' => 'soimg',
                         'title' => '',
                     ]
                 );
@@ -2025,7 +2025,7 @@ class Results
                     's_desc',
                     __('Descending'),
                     [
-                        'class' => "soimg hide",
+                        'class' => 'soimg hide',
                         'title' => '',
                     ]
                 );
@@ -3267,7 +3267,7 @@ class Results
         );
 
         // Class definitions required for grid editing jQuery scripts
-        $edit_anchor_class = "edit_row_anchor";
+        $edit_anchor_class = 'edit_row_anchor';
         if ($clause_is_unique == 0) {
             $edit_anchor_class .= ' nonunique';
         }
@@ -4957,7 +4957,7 @@ class Results
              * the script it calls do not fail
              */
             if (empty($_url_params['table']) && ! empty($_url_params['db'])) {
-                $_url_params['table'] = $GLOBALS['dbi']->fetchValue("SHOW TABLES");
+                $_url_params['table'] = $GLOBALS['dbi']->fetchValue('SHOW TABLES');
                 /* No result (probably no database selected) */
                 if ($_url_params['table'] === false) {
                     unset($_url_params['table']);
@@ -5095,7 +5095,7 @@ class Results
             ) {
                 // Applying Transformations on hex string of binary data
                 // seems more appropriate
-                $result = pack("H*", bin2hex($content));
+                $result = pack('H*', bin2hex($content));
             }
         }
 
diff --git a/libraries/classes/ErrorReport.php b/libraries/classes/ErrorReport.php
index 43c7a2b75f..c399ae402a 100644
--- a/libraries/classes/ErrorReport.php
+++ b/libraries/classes/ErrorReport.php
@@ -95,16 +95,16 @@ class ErrorReport
         $relParams = $this->relation->getRelationsParam();
         // common params for both, php & js exceptions
         $report = [
-            "pma_version" => PMA_VERSION,
-            "browser_name" => PMA_USR_BROWSER_AGENT,
-            "browser_version" => PMA_USR_BROWSER_VER,
-            "user_os" => PMA_USR_OS,
-            "server_software" => $_SERVER['SERVER_SOFTWARE'],
-            "user_agent_string" => $_SERVER['HTTP_USER_AGENT'],
-            "locale" => $PMA_Config->getCookie('pma_lang'),
-            "configuration_storage" =>
-                $relParams['db'] === null ? "disabled" : "enabled",
-            "php_version" => PHP_VERSION,
+            'pma_version' => PMA_VERSION,
+            'browser_name' => PMA_USR_BROWSER_AGENT,
+            'browser_version' => PMA_USR_BROWSER_VER,
+            'user_os' => PMA_USR_OS,
+            'server_software' => $_SERVER['SERVER_SOFTWARE'],
+            'user_agent_string' => $_SERVER['HTTP_USER_AGENT'],
+            'locale' => $PMA_Config->getCookie('pma_lang'),
+            'configuration_storage' =>
+                $relParams['db'] === null ? 'disabled' : 'enabled',
+            'php_version' => PHP_VERSION,
         ];
 
         if ($exceptionType == 'js') {
@@ -112,26 +112,26 @@ class ErrorReport
                 return [];
             }
             $exception = $_POST['exception'];
-            $exception["stack"] = $this->translateStacktrace($exception["stack"]);
+            $exception['stack'] = $this->translateStacktrace($exception['stack']);
 
-            if (isset($exception["url"])) {
-                list($uri, $scriptName) = $this->sanitizeUrl($exception["url"]);
-                $exception["uri"] = $uri;
-                $report["script_name"] = $scriptName;
-                unset($exception["url"]);
-            } elseif (isset($_POST["url"])) {
-                list($uri, $scriptName) = $this->sanitizeUrl($_POST["url"]);
-                $exception["uri"] = $uri;
-                $report["script_name"] = $scriptName;
-                unset($_POST["url"]);
+            if (isset($exception['url'])) {
+                list($uri, $scriptName) = $this->sanitizeUrl($exception['url']);
+                $exception['uri'] = $uri;
+                $report['script_name'] = $scriptName;
+                unset($exception['url']);
+            } elseif (isset($_POST['url'])) {
+                list($uri, $scriptName) = $this->sanitizeUrl($_POST['url']);
+                $exception['uri'] = $uri;
+                $report['script_name'] = $scriptName;
+                unset($_POST['url']);
             } else {
-                $report["script_name"] = null;
+                $report['script_name'] = null;
             }
 
-            $report["exception_type"] = 'js';
-            $report["exception"] = $exception;
+            $report['exception_type'] = 'js';
+            $report['exception'] = $exception;
             if (isset($_POST['microhistory'])) {
-                $report["microhistory"] = $_POST['microhistory'];
+                $report['microhistory'] = $_POST['microhistory'];
             }
 
             if (! empty($_POST['description'])) {
@@ -153,12 +153,12 @@ class ErrorReport
                     && $errorObj->getNumber() != E_USER_WARNING
                 ) {
                     $errors[$i++] = [
-                        "lineNum" => $errorObj->getLine(),
-                        "file" => $errorObj->getFile(),
-                        "type" => $errorObj->getType(),
-                        "msg" => $errorObj->getOnlyMessage(),
-                        "stackTrace" => $errorObj->getBacktrace(5),
-                        "stackhash" => $errorObj->getHash(),
+                        'lineNum' => $errorObj->getLine(),
+                        'file' => $errorObj->getFile(),
+                        'type' => $errorObj->getType(),
+                        'msg' => $errorObj->getOnlyMessage(),
+                        'stackTrace' => $errorObj->getBacktrace(5),
+                        'stackhash' => $errorObj->getHash(),
                     ];
                 }
             }
@@ -167,8 +167,8 @@ class ErrorReport
             if ($i == 0) {
                 return []; // then return empty array
             }
-            $report["exception_type"] = 'php';
-            $report["errors"] = $errors;
+            $report['exception_type'] = 'php';
+            $report['errors'] = $errors;
         } else {
             return [];
         }
@@ -191,16 +191,16 @@ class ErrorReport
     private function sanitizeUrl(string $url): array
     {
         $components = parse_url($url);
-        if (isset($components["fragment"])
-            && preg_match("<PMAURL-\d+:>", $components["fragment"], $matches)
+        if (isset($components['fragment'])
+            && preg_match('<PMAURL-\d+:>', $components['fragment'], $matches)
         ) {
-            $uri = str_replace($matches[0], "", $components["fragment"]);
-            $url = "https://example.com/" . $uri;
+            $uri = str_replace($matches[0], '', $components['fragment']);
+            $url = 'https://example.com/' . $uri;
             $components = parse_url($url);
         }
 
         // get script name
-        preg_match("<([a-zA-Z\-_\d\.]*\.php|js\/[a-zA-Z\-_\d\/\.]*\.js)$>", $components["path"], $matches);
+        preg_match('<([a-zA-Z\-_\d\.]*\.php|js\/[a-zA-Z\-_\d\/\.]*\.js)$>', $components['path'], $matches);
         if (count($matches) < 2) {
             $scriptName = 'index.php';
         } else {
@@ -208,15 +208,15 @@ class ErrorReport
         }
 
         // remove deployment specific details to make uri more generic
-        if (isset($components["query"])) {
-            parse_str($components["query"], $queryArray);
-            unset($queryArray["db"], $queryArray["table"], $queryArray["token"], $queryArray["server"]);
+        if (isset($components['query'])) {
+            parse_str($components['query'], $queryArray);
+            unset($queryArray['db'], $queryArray['table'], $queryArray['token'], $queryArray['server']);
             $query = http_build_query($queryArray);
         } else {
             $query = '';
         }
 
-        $uri = $scriptName . "?" . $query;
+        $uri = $scriptName . '?' . $query;
         return [
             $uri,
             $scriptName,
@@ -234,10 +234,10 @@ class ErrorReport
     {
         return $this->httpRequest->create(
             $this->submissionUrl,
-            "POST",
+            'POST',
             false,
             json_encode($report),
-            "Content-Type: application/json"
+            'Content-Type: application/json'
         );
     }
 
@@ -252,15 +252,15 @@ class ErrorReport
     private function translateStacktrace(array $stack): array
     {
         foreach ($stack as &$level) {
-            foreach ($level["context"] as &$line) {
+            foreach ($level['context'] as &$line) {
                 if (mb_strlen($line) > 80) {
-                    $line = mb_substr($line, 0, 75) . "//...";
+                    $line = mb_substr($line, 0, 75) . '//...';
                 }
             }
-            list($uri, $scriptName) = $this->sanitizeUrl($level["url"]);
-            $level["uri"] = $uri;
-            $level["scriptname"] = $scriptName;
-            unset($level["url"]);
+            list($uri, $scriptName) = $this->sanitizeUrl($level['url']);
+            $level['uri'] = $uri;
+            $level['scriptname'] = $scriptName;
+            unset($level['url']);
         }
         unset($level);
         return $stack;
diff --git a/libraries/classes/Export.php b/libraries/classes/Export.php
index 95786cfa01..7a77d7b412 100644
--- a/libraries/classes/Export.php
+++ b/libraries/classes/Export.php
@@ -40,7 +40,7 @@ class Export
     public function shutdown(): void
     {
         $error = error_get_last();
-        if ($error != null && mb_strpos($error['message'], "execution time")) {
+        if ($error != null && mb_strpos($error['message'], 'execution time')) {
             //set session variable to check if there was error while exporting
             $_SESSION['pma_export_error'] = $error['message'];
         }
@@ -314,7 +314,7 @@ class Export
             $extension_start_pos,
             mb_strlen($filename)
         );
-        $required_extension = "." . $export_plugin->getProperties()->getExtension();
+        $required_extension = '.' . $export_plugin->getProperties()->getExtension();
         if (mb_strtolower($user_extension) != $required_extension) {
             $filename  .= $required_extension;
         }
@@ -1125,15 +1125,15 @@ class Export
      *
      * @return mixed result of the query
      */
-    public function lockTables(string $db, array $tables, string $lockType = "WRITE")
+    public function lockTables(string $db, array $tables, string $lockType = 'WRITE')
     {
         $locks = [];
         foreach ($tables as $table) {
-            $locks[] = Util::backquote($db) . "."
-                . Util::backquote($table) . " " . $lockType;
+            $locks[] = Util::backquote($db) . '.'
+                . Util::backquote($table) . ' ' . $lockType;
         }
 
-        $sql = "LOCK TABLES " . implode(", ", $locks);
+        $sql = 'LOCK TABLES ' . implode(', ', $locks);
         return $this->dbi->tryQuery($sql);
     }
 
@@ -1144,7 +1144,7 @@ class Export
      */
     public function unlockTables()
     {
-        return $this->dbi->tryQuery("UNLOCK TABLES");
+        return $this->dbi->tryQuery('UNLOCK TABLES');
     }
 
     /**
@@ -1208,7 +1208,7 @@ class Export
         // get the specific plugin
         /** @var SchemaPlugin $export_plugin */
         $export_plugin = Plugins::getPlugin(
-            "schema",
+            'schema',
             $export_type,
             'libraries/classes/Plugins/Schema/'
         );
diff --git a/libraries/classes/Font.php b/libraries/classes/Font.php
index faea945069..169a265e24 100644
--- a/libraries/classes/Font.php
+++ b/libraries/classes/Font.php
@@ -28,135 +28,135 @@ class Font
 
         //ijl
         $charLists[] = [
-            "chars" => [
-                "i",
-                "j",
-                "l",
-            ], "modifier" => 0.23,
+            'chars' => [
+                'i',
+                'j',
+                'l',
+            ], 'modifier' => 0.23,
         ];
         //f
         $charLists[] = [
-            "chars" => ["f"],
-            "modifier" => 0.27,
+            'chars' => ['f'],
+            'modifier' => 0.27,
         ];
         //tI
         $charLists[] = [
-            "chars" => [
-                "t",
-                "I",
-            ], "modifier" => 0.28,
+            'chars' => [
+                't',
+                'I',
+            ], 'modifier' => 0.28,
         ];
         //r
         $charLists[] = [
-            "chars" => ["r"],
-            "modifier" => 0.34,
+            'chars' => ['r'],
+            'modifier' => 0.34,
         ];
         //1
         $charLists[] = [
-            "chars" => ["1"],
-            "modifier" => 0.49,
+            'chars' => ['1'],
+            'modifier' => 0.49,
         ];
         //cksvxyzJ
         $charLists[] = [
-            "chars" => [
-                "c",
-                "k",
-                "s",
-                "v",
-                "x",
-                "y",
-                "z",
-                "J",
+            'chars' => [
+                'c',
+                'k',
+                's',
+                'v',
+                'x',
+                'y',
+                'z',
+                'J',
             ],
-            "modifier" => 0.5,
+            'modifier' => 0.5,
         ];
         //abdeghnopquL023456789
         $charLists[] = [
-            "chars" => [
-                "a",
-                "b",
-                "d",
-                "e",
-                "g",
-                "h",
-                "n",
-                "o",
-                "p",
-                "q",
-                "u",
-                "L",
-                "0",
-                "2",
-                "3",
-                "4",
-                "5",
-                "6",
-                "7",
-                "8",
-                "9",
+            'chars' => [
+                'a',
+                'b',
+                'd',
+                'e',
+                'g',
+                'h',
+                'n',
+                'o',
+                'p',
+                'q',
+                'u',
+                'L',
+                '0',
+                '2',
+                '3',
+                '4',
+                '5',
+                '6',
+                '7',
+                '8',
+                '9',
             ],
-            "modifier" => 0.56,
+            'modifier' => 0.56,
         ];
         //FTZ
         $charLists[] = [
-            "chars" => [
-                "F",
-                "T",
-                "Z",
-            ], "modifier" => 0.61,
+            'chars' => [
+                'F',
+                'T',
+                'Z',
+            ], 'modifier' => 0.61,
         ];
         //ABEKPSVXY
         $charLists[] = [
-            "chars" => [
-                "A",
-                "B",
-                "E",
-                "K",
-                "P",
-                "S",
-                "V",
-                "X",
-                "Y",
+            'chars' => [
+                'A',
+                'B',
+                'E',
+                'K',
+                'P',
+                'S',
+                'V',
+                'X',
+                'Y',
             ],
-            "modifier" => 0.67,
+            'modifier' => 0.67,
         ];
         //wCDHNRU
         $charLists[] = [
-            "chars" => [
-                "w",
-                "C",
-                "D",
-                "H",
-                "N",
-                "R",
-                "U",
+            'chars' => [
+                'w',
+                'C',
+                'D',
+                'H',
+                'N',
+                'R',
+                'U',
             ],
-            "modifier" => 0.73,
+            'modifier' => 0.73,
         ];
         //GOQ
         $charLists[] = [
-            "chars" => [
-                "G",
-                "O",
-                "Q",
-            ], "modifier" => 0.78,
+            'chars' => [
+                'G',
+                'O',
+                'Q',
+            ], 'modifier' => 0.78,
         ];
         //mM
         $charLists[] = [
-            "chars" => [
-                "m",
-                "M",
-            ], "modifier" => 0.84,
+            'chars' => [
+                'm',
+                'M',
+            ], 'modifier' => 0.84,
         ];
         //W
         $charLists[] = [
-            "chars" => ["W"],
-            "modifier" => 0.95,
+            'chars' => ['W'],
+            'modifier' => 0.95,
         ];
         //" "
         $charLists[] = [
-            "chars" => [" "],
-            "modifier" => 0.28,
+            'chars' => [' '],
+            'modifier' => 0.28,
         ];
 
         return $charLists;
@@ -182,8 +182,8 @@ class Font
         int $fontSize,
         ?array $charLists = null
     ): int {
-        if (! isset($charLists[0]["chars"], $charLists[0]["modifier"]) || empty($charLists)
-            || ! is_array($charLists[0]["chars"])
+        if (! isset($charLists[0]['chars'], $charLists[0]['modifier']) || empty($charLists)
+            || ! is_array($charLists[0]['chars'])
         ) {
             $charLists = $this->getCharLists();
         }
@@ -195,13 +195,13 @@ class Font
 
         foreach ($charLists as $charList) {
             $count += ((mb_strlen($text)
-                - mb_strlen(str_replace($charList["chars"], "", $text))
-                ) * $charList["modifier"]);
+                - mb_strlen(str_replace($charList['chars'], '', $text))
+                ) * $charList['modifier']);
         }
 
-        $text  = str_replace(" ", "", $text);//remove the " "'s
+        $text  = str_replace(' ', '', $text);//remove the " "'s
         //all other chars
-        $count += (mb_strlen(preg_replace("/[a-z0-9]/i", "", $text)) * 0.3);
+        $count += (mb_strlen(preg_replace('/[a-z0-9]/i', '', $text)) * 0.3);
 
         $modifier = 1;
         $font = mb_strtolower($font);
diff --git a/libraries/classes/Footer.php b/libraries/classes/Footer.php
index 5e7b5fe546..f8b285fbbc 100644
--- a/libraries/classes/Footer.php
+++ b/libraries/classes/Footer.php
@@ -111,14 +111,14 @@ class Footer
     {
         if ((is_object($object) || is_array($object)) && $object) {
             if ($object instanceof Traversable) {
-                $object = "***ITERATOR***";
+                $object = '***ITERATOR***';
             } elseif (! in_array($object, $stack, true)) {
                 $stack[] = $object;
                 foreach ($object as &$subobject) {
                     self::_removeRecursion($subobject, $stack);
                 }
             } else {
-                $object = "***RECURSION***";
+                $object = '***RECURSION***';
             }
         }
         return $object;
diff --git a/libraries/classes/Gis/GisGeometry.php b/libraries/classes/Gis/GisGeometry.php
index 5cb14e6bda..35bca3826a 100644
--- a/libraries/classes/Gis/GisGeometry.php
+++ b/libraries/classes/Gis/GisGeometry.php
@@ -148,11 +148,11 @@ abstract class GisGeometry
     protected function setMinMax($point_set, array $min_max)
     {
         // Separate each point
-        $points = explode(",", $point_set);
+        $points = explode(',', $point_set);
 
         foreach ($points as $point) {
             // Extract coordinates of the point
-            $cordinates = explode(" ", $point);
+            $cordinates = explode(' ', $point);
 
             $x = (float) $cordinates[0];
             if (! isset($min_max['maxX']) || $x > $min_max['maxX']) {
@@ -191,10 +191,10 @@ abstract class GisGeometry
         $wkt = '';
 
         if (preg_match("/^'" . $geom_types . "\(.*\)',[0-9]*$/i", $value)) {
-            $last_comma = mb_strripos($value, ",");
+            $last_comma = mb_strripos($value, ',');
             $srid = trim(mb_substr($value, $last_comma + 1));
             $wkt = trim(mb_substr($value, 1, $last_comma - 2));
-        } elseif (preg_match("/^" . $geom_types . "\(.*\)$/i", $value)) {
+        } elseif (preg_match('/^' . $geom_types . '\(.*\)$/i', $value)) {
             $wkt = $value;
         }
 
@@ -219,12 +219,12 @@ abstract class GisGeometry
         $points_arr = [];
 
         // Separate each point
-        $points = explode(",", $point_set);
+        $points = explode(',', $point_set);
 
         foreach ($points as $point) {
             $point = str_replace(['(', ')'], '', $point);
             // Extract coordinates of the point
-            $cordinates = explode(" ", $point);
+            $cordinates = explode(' ', $point);
 
             if (isset($cordinates[0], $cordinates[1]) && trim($cordinates[0]) != '' && trim($cordinates[1]) != '') {
                 if ($scale_data != null) {
@@ -267,7 +267,7 @@ abstract class GisGeometry
     {
         $ol_array = 'new Array(';
         foreach ($polygons as $polygon) {
-            $rings = explode("),(", $polygon);
+            $rings = explode('),(', $polygon);
             $ol_array .= $this->getPolygonForOpenLayers($rings, $srid) . ', ';
         }
 
diff --git a/libraries/classes/Gis/GisMultiLineString.php b/libraries/classes/Gis/GisMultiLineString.php
index 4eb7493de5..bcaf94b099 100644
--- a/libraries/classes/Gis/GisMultiLineString.php
+++ b/libraries/classes/Gis/GisMultiLineString.php
@@ -64,7 +64,7 @@ class GisMultiLineString extends GisGeometry
                 mb_strlen($spatial) - 19
             );
         // Separate each linestring
-        $linestirngs = explode("),(", $multilinestirng);
+        $linestirngs = explode('),(', $multilinestirng);
 
         foreach ($linestirngs as $linestring) {
             $min_max = $this->setMinMax($linestring, $min_max);
@@ -107,7 +107,7 @@ class GisMultiLineString extends GisGeometry
                 mb_strlen($spatial) - 19
             );
         // Separate each linestring
-        $linestirngs = explode("),(", $multilinestirng);
+        $linestirngs = explode('),(', $multilinestirng);
 
         $first_line = true;
         foreach ($linestirngs as $linestring) {
@@ -181,7 +181,7 @@ class GisMultiLineString extends GisGeometry
                 mb_strlen($spatial) - 19
             );
         // Separate each linestring
-        $linestirngs = explode("),(", $multilinestirng);
+        $linestirngs = explode('),(', $multilinestirng);
 
         $first_line = true;
         foreach ($linestirngs as $linestring) {
@@ -243,7 +243,7 @@ class GisMultiLineString extends GisGeometry
                 mb_strlen($spatial) - 19
             );
         // Separate each linestring
-        $linestirngs = explode("),(", $multilinestirng);
+        $linestirngs = explode('),(', $multilinestirng);
 
         $row = '';
         foreach ($linestirngs as $linestring) {
@@ -298,7 +298,7 @@ class GisMultiLineString extends GisGeometry
                 mb_strlen($spatial) - 19
             );
         // Separate each linestring
-        $linestirngs = explode("),(", $multilinestirng);
+        $linestirngs = explode('),(', $multilinestirng);
 
         $row .= 'vectorLayer.addFeatures(new OpenLayers.Feature.Vector('
             . 'new OpenLayers.Geometry.MultiLineString('
@@ -428,7 +428,7 @@ class GisMultiLineString extends GisGeometry
                 mb_strlen($wkt) - 19
             );
         // Separate each linestring
-        $linestirngs = explode("),(", $multilinestirng);
+        $linestirngs = explode('),(', $multilinestirng);
         $params[$index]['MULTILINESTRING']['no_of_lines'] = count($linestirngs);
 
         $j = 0;
diff --git a/libraries/classes/Gis/GisMultiPolygon.php b/libraries/classes/Gis/GisMultiPolygon.php
index aa56dc1342..b5ca39d395 100644
--- a/libraries/classes/Gis/GisMultiPolygon.php
+++ b/libraries/classes/Gis/GisMultiPolygon.php
@@ -64,15 +64,15 @@ class GisMultiPolygon extends GisGeometry
                 mb_strlen($spatial) - 18
             );
         // Separate each polygon
-        $polygons = explode(")),((", $multipolygon);
+        $polygons = explode(')),((', $multipolygon);
 
         foreach ($polygons as $polygon) {
             // If the polygon doesn't have an inner ring, use polygon itself
-            if (mb_strpos($polygon, "),(") === false) {
+            if (mb_strpos($polygon, '),(') === false) {
                 $ring = $polygon;
             } else {
                 // Separate outer ring and use it to determine min-max
-                $parts = explode("),(", $polygon);
+                $parts = explode('),(', $polygon);
                 $ring = $parts[0];
             }
             $min_max = $this->setMinMax($ring, $min_max);
@@ -115,17 +115,17 @@ class GisMultiPolygon extends GisGeometry
                 mb_strlen($spatial) - 18
             );
         // Separate each polygon
-        $polygons = explode(")),((", $multipolygon);
+        $polygons = explode(')),((', $multipolygon);
 
         $first_poly = true;
         $points_arr = [];
         foreach ($polygons as $polygon) {
             // If the polygon doesn't have an inner polygon
-            if (mb_strpos($polygon, "),(") === false) {
+            if (mb_strpos($polygon, '),(') === false) {
                 $points_arr = $this->extractPoints($polygon, $scale_data, true);
             } else {
                 // Separate outer and inner polygons
-                $parts = explode("),(", $polygon);
+                $parts = explode('),(', $polygon);
                 $outer = $parts[0];
                 $inner = array_slice($parts, 1);
 
@@ -196,16 +196,16 @@ class GisMultiPolygon extends GisGeometry
                 mb_strlen($spatial) - 18
             );
         // Separate each polygon
-        $polygons = explode(")),((", $multipolygon);
+        $polygons = explode(')),((', $multipolygon);
 
         $first_poly = true;
         foreach ($polygons as $polygon) {
             // If the polygon doesn't have an inner polygon
-            if (mb_strpos($polygon, "),(") === false) {
+            if (mb_strpos($polygon, '),(') === false) {
                 $points_arr = $this->extractPoints($polygon, $scale_data, true);
             } else {
                 // Separate outer and inner polygons
-                $parts = explode("),(", $polygon);
+                $parts = explode('),(', $polygon);
                 $outer = $parts[0];
                 $inner = array_slice($parts, 1);
 
@@ -273,17 +273,17 @@ class GisMultiPolygon extends GisGeometry
                 mb_strlen($spatial) - 18
             );
         // Separate each polygon
-        $polygons = explode(")),((", $multipolygon);
+        $polygons = explode(')),((', $multipolygon);
 
         foreach ($polygons as $polygon) {
             $row .= '<path d="';
 
             // If the polygon doesn't have an inner polygon
-            if (mb_strpos($polygon, "),(") === false) {
+            if (mb_strpos($polygon, '),(') === false) {
                 $row .= $this->_drawPath($polygon, $scale_data);
             } else {
                 // Separate outer and inner polygons
-                $parts = explode("),(", $polygon);
+                $parts = explode('),(', $polygon);
                 $outer = $parts[0];
                 $inner = array_slice($parts, 1);
 
@@ -340,7 +340,7 @@ class GisMultiPolygon extends GisGeometry
                 mb_strlen($spatial) - 18
             );
         // Separate each polygon
-        $polygons = explode(")),((", $multipolygon);
+        $polygons = explode(')),((', $multipolygon);
 
         $row .= 'vectorLayer.addFeatures(new OpenLayers.Feature.Vector('
             . 'new OpenLayers.Geometry.MultiPolygon('
@@ -575,7 +575,7 @@ class GisMultiPolygon extends GisGeometry
                 mb_strlen($wkt) - 18
             );
         // Separate each polygon
-        $polygons = explode(")),((", $multipolygon);
+        $polygons = explode(')),((', $multipolygon);
 
         $param_row =& $params[$index]['MULTIPOLYGON'];
         $param_row['no_of_polygons'] = count($polygons);
@@ -583,7 +583,7 @@ class GisMultiPolygon extends GisGeometry
         $k = 0;
         foreach ($polygons as $polygon) {
             // If the polygon doesn't have an inner polygon
-            if (mb_strpos($polygon, "),(") === false) {
+            if (mb_strpos($polygon, '),(') === false) {
                 $param_row[$k]['no_of_lines'] = 1;
                 $points_arr = $this->extractPoints($polygon, null);
                 $no_of_points = count($points_arr);
@@ -594,7 +594,7 @@ class GisMultiPolygon extends GisGeometry
                 }
             } else {
                 // Separate outer and inner polygons
-                $parts = explode("),(", $polygon);
+                $parts = explode('),(', $polygon);
                 $param_row[$k]['no_of_lines'] = count($parts);
                 $j = 0;
                 foreach ($parts as $ring) {
diff --git a/libraries/classes/Gis/GisPolygon.php b/libraries/classes/Gis/GisPolygon.php
index 3bebd71ea9..950b4d17a4 100644
--- a/libraries/classes/Gis/GisPolygon.php
+++ b/libraries/classes/Gis/GisPolygon.php
@@ -62,11 +62,11 @@ class GisPolygon extends GisGeometry
         );
 
         // If the polygon doesn't have an inner ring, use polygon itself
-        if (mb_strpos($polygon, "),(") === false) {
+        if (mb_strpos($polygon, '),(') === false) {
             $ring = $polygon;
         } else {
             // Separate outer ring and use it to determine min-max
-            $parts = explode("),(", $polygon);
+            $parts = explode('),(', $polygon);
             $ring = $parts[0];
         }
 
@@ -107,11 +107,11 @@ class GisPolygon extends GisGeometry
         );
 
         // If the polygon doesn't have an inner polygon
-        if (mb_strpos($polygon, "),(") === false) {
+        if (mb_strpos($polygon, '),(') === false) {
             $points_arr = $this->extractPoints($polygon, $scale_data, true);
         } else {
             // Separate outer and inner polygons
-            $parts = explode("),(", $polygon);
+            $parts = explode('),(', $polygon);
             $outer = $parts[0];
             $inner = array_slice($parts, 1);
 
@@ -174,11 +174,11 @@ class GisPolygon extends GisGeometry
         );
 
         // If the polygon doesn't have an inner polygon
-        if (mb_strpos($polygon, "),(") === false) {
+        if (mb_strpos($polygon, '),(') === false) {
             $points_arr = $this->extractPoints($polygon, $scale_data, true);
         } else {
             // Separate outer and inner polygons
-            $parts = explode("),(", $polygon);
+            $parts = explode('),(', $polygon);
             $outer = $parts[0];
             $inner = array_slice($parts, 1);
 
@@ -239,11 +239,11 @@ class GisPolygon extends GisGeometry
         $row = '<path d="';
 
         // If the polygon doesn't have an inner polygon
-        if (mb_strpos($polygon, "),(") === false) {
+        if (mb_strpos($polygon, '),(') === false) {
             $row .= $this->_drawPath($polygon, $scale_data);
         } else {
             // Separate outer and inner polygons
-            $parts = explode("),(", $polygon);
+            $parts = explode('),(', $polygon);
             $outer = $parts[0];
             $inner = array_slice($parts, 1);
 
@@ -301,7 +301,7 @@ class GisPolygon extends GisGeometry
             );
 
         // Separate outer and inner polygons
-        $parts = explode("),(", $polygon);
+        $parts = explode('),(', $polygon);
         $row .= 'vectorLayer.addFeatures(new OpenLayers.Feature.Vector('
             . $this->getPolygonForOpenLayers($parts, $srid)
             . ', null, ' . json_encode($style_options) . '));';
@@ -597,7 +597,7 @@ class GisPolygon extends GisGeometry
                 mb_strlen($wkt) - 11
             );
         // Separate each linestring
-        $linerings = explode("),(", $polygon);
+        $linerings = explode('),(', $polygon);
         $params[$index]['POLYGON']['no_of_lines'] = count($linerings);
 
         $j = 0;
diff --git a/libraries/classes/Gis/GisVisualization.php b/libraries/classes/Gis/GisVisualization.php
index ce7b3188cc..b3c8ad9aa0 100644
--- a/libraries/classes/Gis/GisVisualization.php
+++ b/libraries/classes/Gis/GisVisualization.php
@@ -268,7 +268,7 @@ class GisVisualization
                 $extension_start_pos,
                 mb_strlen($file_name)
             );
-        $required_extension = "." . $ext;
+        $required_extension = '.' . $ext;
         if (mb_strtolower($user_extension) != $required_extension) {
             $file_name .= $required_extension;
         }
diff --git a/libraries/classes/Header.php b/libraries/classes/Header.php
index acfc35e654..b353ee71ec 100644
--- a/libraries/classes/Header.php
+++ b/libraries/classes/Header.php
@@ -563,25 +563,25 @@ class Header
             . "style-src 'self' 'unsafe-inline' "
             . $captcha_url
             . $GLOBALS['cfg']['CSPAllow']
-            . ";"
+            . ';'
             . "img-src 'self' data: "
             . $GLOBALS['cfg']['CSPAllow']
             . $map_tile_urls
             . $captcha_url
-            . ";"
+            . ';'
             . "object-src 'none';"
         );
         header(
             "X-Content-Security-Policy: default-src 'self' "
             . $captcha_url
             . $GLOBALS['cfg']['CSPAllow'] . ';'
-            . "options inline-script eval-script;"
-            . "referrer no-referrer;"
+            . 'options inline-script eval-script;'
+            . 'referrer no-referrer;'
             . "img-src 'self' data: "
             . $GLOBALS['cfg']['CSPAllow']
             . $map_tile_urls
             . $captcha_url
-            . ";"
+            . ';'
             . "object-src 'none';"
         );
         header(
@@ -592,7 +592,7 @@ class Header
             . $captcha_url
             . $GLOBALS['cfg']['CSPAllow']
             . " 'unsafe-inline' 'unsafe-eval';"
-            . "referrer no-referrer;"
+            . 'referrer no-referrer;'
             . "style-src 'self' 'unsafe-inline' "
             . $captcha_url
             . ';'
@@ -600,7 +600,7 @@ class Header
             . $GLOBALS['cfg']['CSPAllow']
             . $map_tile_urls
             . $captcha_url
-            . ";"
+            . ';'
             . "object-src 'none';"
         );
         // Re-enable possible disabled XSS filters
@@ -698,6 +698,6 @@ class Header
      */
     public static function getVersionParameter(): string
     {
-        return "v=" . urlencode(PMA_VERSION);
+        return 'v=' . urlencode(PMA_VERSION);
     }
 }
diff --git a/libraries/classes/Html/Generator.php b/libraries/classes/Html/Generator.php
index 5faffe6852..3c9c331325 100644
--- a/libraries/classes/Html/Generator.php
+++ b/libraries/classes/Html/Generator.php
@@ -351,7 +351,7 @@ class Generator
     {
         $template = new Template();
         // Do the logic first
-        $link = "$action&amp;" . urlencode($select_name) . '=';
+        $link = $action . '&amp;' . urlencode($select_name) . '=';
         $link_on = $link . urlencode($options[1]['value']);
         $link_off = $link . urlencode($options[0]['value']);
 
@@ -1021,7 +1021,7 @@ class Generator
     public static function showDocumentationLink($link, $target = 'documentation', $bbcode = false): string
     {
         if ($bbcode) {
-            return "[a@$link@$target][dochelpicon][/a]";
+            return '[a@' . $link . '@' . $target . '][dochelpicon][/a]';
         }
 
         return '<a href="' . $link . '" target="' . $target . '">'
@@ -1257,16 +1257,16 @@ class Generator
         $alternate = htmlspecialchars($alternate);
 
         if (isset($attributes['class'])) {
-            $attributes['class'] = "icon ic_$image " . $attributes['class'];
+            $attributes['class'] = 'icon ic_' . $image . ' ' . $attributes['class'];
         } else {
-            $attributes['class'] = "icon ic_$image";
+            $attributes['class'] = 'icon ic_' . $image;
         }
 
         // set all other attributes
         $attr_str = '';
         foreach ($attributes as $key => $value) {
             if (! in_array($key, ['alt', 'title'])) {
-                $attr_str .= " $key=\"$value\"";
+                $attr_str .= ' ' . $key . '="' . $value . '"';
             }
         }
 
diff --git a/libraries/classes/Import.php b/libraries/classes/Import.php
index dc058fae4d..b803485bbd 100644
--- a/libraries/classes/Import.php
+++ b/libraries/classes/Import.php
@@ -96,7 +96,7 @@ class Import
 
         // USE query changes the database, son need to track
         // while running multiple queries
-        $is_use_query = mb_stripos($sql, "use ") !== false;
+        $is_use_query = mb_stripos($sql, 'use ') !== false;
 
         $msg = '# ';
         if ($result === false) { // execution failed
@@ -451,7 +451,7 @@ class Import
     public function getColumnAlphaName(int $num): string
     {
         $A = 65; // ASCII value for capital "A"
-        $col_name = "";
+        $col_name = '';
 
         if ($num > 26) {
             $div = (int) ($num / 26);
@@ -535,7 +535,7 @@ class Import
         return (int) substr(
             $last_cumulative_size,
             0,
-            strpos($last_cumulative_size, ",")
+            strpos($last_cumulative_size, ',')
         );
     }
 
@@ -552,8 +552,8 @@ class Import
     {
         return (int) substr(
             $last_cumulative_size,
-            strpos($last_cumulative_size, ",") + 1,
-            strlen($last_cumulative_size) - strpos($last_cumulative_size, ",")
+            strpos($last_cumulative_size, ',') + 1,
+            strlen($last_cumulative_size) - strpos($last_cumulative_size, ',')
         );
     }
 
@@ -569,7 +569,7 @@ class Import
     public function getDecimalSize(string $cell): array
     {
         $curr_size = mb_strlen($cell);
-        $decPos = mb_strpos($cell, ".");
+        $decPos = mb_strpos($cell, '.');
         $decPrecision = ($curr_size - 1) - $decPos;
 
         $m = $curr_size - 1;
@@ -578,7 +578,7 @@ class Import
         return [
             $m,
             $d,
-            $m . "," . $d,
+            $m . ',' . $d,
         ];
     }
 
@@ -687,7 +687,7 @@ class Import
                 if ($size[self::M] > $oldM || $size[self::D] > $oldD) {
                     /* Take the largest of both types */
                     return (string) ((($size[self::M] > $oldM) ? $size[self::M] : $oldM)
-                        . "," . (($size[self::D] > $oldD) ? $size[self::D] : $oldD));
+                        . ',' . (($size[self::D] > $oldD) ? $size[self::D] : $oldD));
                 }
 
                 return $last_cumulative_size;
@@ -702,7 +702,7 @@ class Import
                     return $size[self::FULL];
                 }
 
-                return ($last_cumulative_size . "," . $size[self::D]);
+                return ($last_cumulative_size . ',' . $size[self::D]);
             } elseif (! isset($last_cumulative_type) || $last_cumulative_type == self::NONE) {
                 /**
                  * This is the first row to be analyzed
@@ -750,7 +750,7 @@ class Import
                 }
 
                 /* Use $newInt + $oldD as new M */
-                return (($newInt + $oldD) . "," . $oldD);
+                return (($newInt + $oldD) . ',' . $oldD);
             } elseif ($last_cumulative_type == self::BIGINT || $last_cumulative_type == self::INT) {
                 /**
                  * The last cumulative type was BIGINT or INT
@@ -819,8 +819,8 @@ class Import
         }
 
         if ($cell == (string) (float) $cell
-            && mb_strpos($cell, ".") !== false
-            && mb_substr_count($cell, ".") === 1
+            && mb_strpos($cell, '.') !== false
+            && mb_substr_count($cell, '.') === 1
         ) {
             return self::DECIMAL;
         }
@@ -968,13 +968,13 @@ class Import
         if (isset($options['db_collation']) && $options['db_collation'] !== null) {
             $collation = $options['db_collation'];
         } else {
-            $collation = "utf8_general_ci";
+            $collation = 'utf8_general_ci';
         }
 
         if (isset($options['db_charset']) && $options['db_charset'] !== null) {
             $charset = $options['db_charset'];
         } else {
-            $charset = "utf8";
+            $charset = 'utf8';
         }
 
         if (isset($options['create_db'])) {
@@ -987,9 +987,9 @@ class Import
         $sql = [];
 
         if ($create_db) {
-            $sql[] = "CREATE DATABASE IF NOT EXISTS " . Util::backquote($db_name)
-                . " DEFAULT CHARACTER SET " . $charset . " COLLATE " . $collation
-                . ";";
+            $sql[] = 'CREATE DATABASE IF NOT EXISTS ' . Util::backquote($db_name)
+                . ' DEFAULT CHARACTER SET ' . $charset . ' COLLATE ' . $collation
+                . ';';
         }
 
         /**
@@ -1043,11 +1043,11 @@ class Import
 
         if ($analyses != null) {
             $type_array = [
-                self::NONE => "NULL",
-                self::VARCHAR => "varchar",
-                self::INT => "int",
-                self::DECIMAL => "decimal",
-                self::BIGINT => "bigint",
+                self::NONE => 'NULL',
+                self::VARCHAR => 'varchar',
+                self::INT => 'int',
+                self::DECIMAL => 'decimal',
+                self::BIGINT => 'bigint',
                 self::GEOMETRY => 'geometry',
             ];
 
@@ -1060,9 +1060,9 @@ class Import
             $num_tables = count($tables);
             for ($i = 0; $i < $num_tables; ++$i) {
                 $num_cols = count($tables[$i][self::COL_NAMES]);
-                $tempSQLStr = "CREATE TABLE IF NOT EXISTS "
+                $tempSQLStr = 'CREATE TABLE IF NOT EXISTS '
                 . Util::backquote($db_name)
-                . '.' . Util::backquote($tables[$i][self::TBL_NAME]) . " (";
+                . '.' . Util::backquote($tables[$i][self::TBL_NAME]) . ' (';
                 for ($j = 0; $j < $num_cols; ++$j) {
                     $size = $analyses[$i][self::SIZES][$j];
                     if ((int) $size == 0) {
@@ -1071,18 +1071,18 @@ class Import
 
                     $tempSQLStr .= Util::backquote(
                         $tables[$i][self::COL_NAMES][$j]
-                    ) . " "
+                    ) . ' '
                     . $type_array[$analyses[$i][self::TYPES][$j]];
                     if ($analyses[$i][self::TYPES][$j] != self::GEOMETRY) {
-                        $tempSQLStr .= "(" . $size . ")";
+                        $tempSQLStr .= '(' . $size . ')';
                     }
 
                     if ($j != (count($tables[$i][self::COL_NAMES]) - 1)) {
-                        $tempSQLStr .= ", ";
+                        $tempSQLStr .= ', ';
                     }
                 }
-                $tempSQLStr .= ") DEFAULT CHARACTER SET " . $charset
-                    . " COLLATE " . $collation . ";";
+                $tempSQLStr .= ') DEFAULT CHARACTER SET ' . $charset
+                    . ' COLLATE ' . $collation . ';';
 
                 /**
                  * Each SQL statement is executed immediately
@@ -1098,28 +1098,28 @@ class Import
          *
          * Only one insert query is formed for each table
          */
-        $tempSQLStr = "";
+        $tempSQLStr = '';
         $col_count = 0;
         $num_tables = count($tables);
         for ($i = 0; $i < $num_tables; ++$i) {
             $num_cols = count($tables[$i][self::COL_NAMES]);
             $num_rows = count($tables[$i][self::ROWS]);
 
-            $tempSQLStr = "INSERT INTO " . Util::backquote($db_name) . '.'
-                . Util::backquote($tables[$i][self::TBL_NAME]) . " (";
+            $tempSQLStr = 'INSERT INTO ' . Util::backquote($db_name) . '.'
+                . Util::backquote($tables[$i][self::TBL_NAME]) . ' (';
 
             for ($m = 0; $m < $num_cols; ++$m) {
                 $tempSQLStr .= Util::backquote($tables[$i][self::COL_NAMES][$m]);
 
                 if ($m != ($num_cols - 1)) {
-                    $tempSQLStr .= ", ";
+                    $tempSQLStr .= ', ';
                 }
             }
 
-            $tempSQLStr .= ") VALUES ";
+            $tempSQLStr .= ') VALUES ';
 
             for ($j = 0; $j < $num_rows; ++$j) {
-                $tempSQLStr .= "(";
+                $tempSQLStr .= '(';
 
                 for ($k = 0; $k < $num_cols; ++$k) {
                     // If fully formatted SQL, no need to enclose
@@ -1141,15 +1141,15 @@ class Import
                             $is_varchar = false;
                         }
 
-                        $tempSQLStr .= $is_varchar ? "'" : "";
+                        $tempSQLStr .= $is_varchar ? "'" : '';
                         $tempSQLStr .= $GLOBALS['dbi']->escapeString(
                             (string) $tables[$i][self::ROWS][$j][$k]
                         );
-                        $tempSQLStr .= $is_varchar ? "'" : "";
+                        $tempSQLStr .= $is_varchar ? "'" : '';
                     }
 
                     if ($k != ($num_cols - 1)) {
-                        $tempSQLStr .= ", ";
+                        $tempSQLStr .= ', ';
                     }
 
                     if ($col_count == ($num_cols - 1)) {
@@ -1162,7 +1162,7 @@ class Import
                     unset($tables[$i][self::ROWS][$j][$k]);
                 }
 
-                $tempSQLStr .= ")";
+                $tempSQLStr .= ')';
 
                 if ($j != ($num_rows - 1)) {
                     $tempSQLStr .= ",\n ";
@@ -1173,7 +1173,7 @@ class Import
                 unset($tables[$i][self::ROWS][$j]);
             }
 
-            $tempSQLStr .= ";";
+            $tempSQLStr .= ';';
 
             /**
              * Each SQL statement is executed immediately
diff --git a/libraries/classes/Index.php b/libraries/classes/Index.php
index 62a454f37c..362fafad4a 100644
--- a/libraries/classes/Index.php
+++ b/libraries/classes/Index.php
@@ -531,16 +531,16 @@ class Index
      */
     public function generateIndexTypeSelector()
     {
-        $types = ["" => "--"];
+        $types = ['' => '--'];
         foreach (Index::getIndexTypes() as $type) {
             $types[$type] = $type;
         }
 
         return Html\Forms\Fields\DropDown::generate(
-            "index[Index_type]",
+            'index[Index_type]',
             $types,
             $this->_type,
-            "select_index_type"
+            'select_index_type'
         );
     }
 
@@ -685,7 +685,7 @@ class Index
         $indexes = Index::getFromTable($table, $schema);
 
         $no_indexes_class = count($indexes) > 0 ? ' hide' : '';
-        $no_indexes  = "<div class='no_indexes_defined$no_indexes_class'>";
+        $no_indexes  = "<div class='no_indexes_defined" . $no_indexes_class . "'>";
         $no_indexes .= Message::notice(__('No index defined!'))->getDisplay();
         $no_indexes .= '</div>';
 
diff --git a/libraries/classes/InsertEdit.php b/libraries/classes/InsertEdit.php
index f50bbf65ae..2bbfd11fd1 100644
--- a/libraries/classes/InsertEdit.php
+++ b/libraries/classes/InsertEdit.php
@@ -2020,7 +2020,7 @@ class InsertEdit
         } elseif ((substr($column['True_Type'], 0, 9) == 'timestamp'
             || $column['True_Type'] == 'datetime'
             || $column['True_Type'] == 'time')
-            && (mb_strpos($current_row[$column['Field']], ".") !== false)
+            && (mb_strpos($current_row[$column['Field']], '.') !== false)
         ) {
             $current_row[$column['Field']] = $as_is
                 ? $current_row[$column['Field']]
@@ -2613,12 +2613,12 @@ class InsertEdit
             && in_array($multi_edit_funcs[$key], $func_optional_param))
         ) {
             if ((isset($multi_edit_salt[$key])
-                && ($multi_edit_funcs[$key] == "AES_ENCRYPT"
-                || $multi_edit_funcs[$key] == "AES_DECRYPT"))
+                && ($multi_edit_funcs[$key] == 'AES_ENCRYPT'
+                || $multi_edit_funcs[$key] == 'AES_DECRYPT'))
                 || (! empty($multi_edit_salt[$key])
-                && ($multi_edit_funcs[$key] == "DES_ENCRYPT"
-                || $multi_edit_funcs[$key] == "DES_DECRYPT"
-                || $multi_edit_funcs[$key] == "ENCRYPT"))
+                && ($multi_edit_funcs[$key] == 'DES_ENCRYPT'
+                || $multi_edit_funcs[$key] == 'DES_DECRYPT'
+                || $multi_edit_funcs[$key] == 'ENCRYPT'))
             ) {
                 return $multi_edit_funcs[$key] . '(' . $current_value . ",'"
                     . $this->dbi->escapeString($multi_edit_salt[$key]) . "')";
@@ -3319,7 +3319,7 @@ class InsertEdit
 
         //add data attributes "no of decimals" and "data type"
         $no_decimals = 0;
-        $type = current(explode("(", $column['pma_type']));
+        $type = current(explode('(', $column['pma_type']));
         if (preg_match('/\(([^()]+)\)/', $column['pma_type'], $match)) {
             $match[0] = trim($match[0], '()');
             $no_decimals = $match[0];
diff --git a/libraries/classes/IpAllowDeny.php b/libraries/classes/IpAllowDeny.php
index 7662f51fc0..9fa4326e3f 100644
--- a/libraries/classes/IpAllowDeny.php
+++ b/libraries/classes/IpAllowDeny.php
@@ -230,7 +230,7 @@ class IpAllowDeny
      */
     public function allow()
     {
-        return $this->allowDeny("allow");
+        return $this->allowDeny('allow');
     }
 
     /**
@@ -244,7 +244,7 @@ class IpAllowDeny
      */
     public function deny()
     {
-        return $this->allowDeny("deny");
+        return $this->allowDeny('deny');
     }
 
     /**
diff --git a/libraries/classes/LanguageManager.php b/libraries/classes/LanguageManager.php
index 9ef41b6e04..980816200c 100644
--- a/libraries/classes/LanguageManager.php
+++ b/libraries/classes/LanguageManager.php
@@ -710,8 +710,8 @@ class LanguageManager
             $path = LOCALE_PATH
                 . '/' . $file
                 . '/LC_MESSAGES/phpmyadmin.mo';
-            if ($file != "."
-                && $file != ".."
+            if ($file != '.'
+                && $file != '..'
                 && @file_exists($path)
             ) {
                 $result[] = $file;
diff --git a/libraries/classes/ListDatabase.php b/libraries/classes/ListDatabase.php
index 79e0820273..0dc006ff62 100644
--- a/libraries/classes/ListDatabase.php
+++ b/libraries/classes/ListDatabase.php
@@ -66,15 +66,15 @@ class ListDatabase extends ListAbstract
     protected function retrieve($like_db_name = null)
     {
         $database_list = [];
-        $command = "";
+        $command = '';
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
-            $command .= "SELECT `SCHEMA_NAME` FROM `INFORMATION_SCHEMA`.`SCHEMATA`";
+            $command .= 'SELECT `SCHEMA_NAME` FROM `INFORMATION_SCHEMA`.`SCHEMATA`';
             if (null !== $like_db_name) {
                 $command .= " WHERE `SCHEMA_NAME` LIKE '" . $like_db_name . "'";
             }
         } else {
             if ($GLOBALS['dbs_to_test'] === false || null !== $like_db_name) {
-                $command .= "SHOW DATABASES";
+                $command .= 'SHOW DATABASES';
                 if (null !== $like_db_name) {
                     $command .= " LIKE '" . $like_db_name . "'";
                 }
diff --git a/libraries/classes/Menu.php b/libraries/classes/Menu.php
index 15f47f9eff..3a1d0ba289 100644
--- a/libraries/classes/Menu.php
+++ b/libraries/classes/Menu.php
@@ -142,15 +142,15 @@ class Menu
         $cfgRelation = $this->relation->getRelationsParam();
         if ($cfgRelation['menuswork']) {
             $groupTable = Util::backquote($cfgRelation['db'])
-                . "."
+                . '.'
                 . Util::backquote($cfgRelation['usergroups']);
             $userTable = Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['users']);
+                . '.' . Util::backquote($cfgRelation['users']);
 
-            $sql_query = "SELECT `tab` FROM " . $groupTable
+            $sql_query = 'SELECT `tab` FROM ' . $groupTable
                 . " WHERE `allowed` = 'N'"
                 . " AND `tab` LIKE '" . $level . "%'"
-                . " AND `usergroup` = (SELECT usergroup FROM "
+                . ' AND `usergroup` = (SELECT usergroup FROM '
                 . $userTable . " WHERE `username` = '"
                 . $GLOBALS['dbi']->escapeString($GLOBALS['cfg']['Server']['user']) . "')";
 
diff --git a/libraries/classes/Message.php b/libraries/classes/Message.php
index 1350675990..125e79c77a 100644
--- a/libraries/classes/Message.php
+++ b/libraries/classes/Message.php
@@ -817,7 +817,7 @@ class Message
         } else {
             $image = 's_notice';
         }
-        $message = self::notice(Html\Generator::getImage($image)) . " " . $message;
+        $message = self::notice(Html\Generator::getImage($image)) . ' ' . $message;
         return $message;
     }
 }
diff --git a/libraries/classes/Navigation/Navigation.php b/libraries/classes/Navigation/Navigation.php
index 0d9e7032cf..ec271da0eb 100644
--- a/libraries/classes/Navigation/Navigation.php
+++ b/libraries/classes/Navigation/Navigation.php
@@ -154,15 +154,15 @@ class Navigation
         $tableName = null
     ) {
         $navTable = Util::backquote($GLOBALS['cfgRelation']['db'])
-            . "." . Util::backquote($GLOBALS['cfgRelation']['navigationhiding']);
-        $sqlQuery = "INSERT INTO " . $navTable
-            . "(`username`, `item_name`, `item_type`, `db_name`, `table_name`)"
-            . " VALUES ("
+            . '.' . Util::backquote($GLOBALS['cfgRelation']['navigationhiding']);
+        $sqlQuery = 'INSERT INTO ' . $navTable
+            . '(`username`, `item_name`, `item_type`, `db_name`, `table_name`)'
+            . ' VALUES ('
             . "'" . $this->dbi->escapeString($GLOBALS['cfg']['Server']['user']) . "',"
             . "'" . $this->dbi->escapeString($itemName) . "',"
             . "'" . $this->dbi->escapeString($itemType) . "',"
             . "'" . $this->dbi->escapeString($dbName) . "',"
-            . "'" . (! empty($tableName) ? $this->dbi->escapeString($tableName) : "" )
+            . "'" . (! empty($tableName) ? $this->dbi->escapeString($tableName) : '' )
             . "')";
         $this->relation->queryAsControlUser($sqlQuery, false);
     }
@@ -185,9 +185,9 @@ class Navigation
         $tableName = null
     ) {
         $navTable = Util::backquote($GLOBALS['cfgRelation']['db'])
-            . "." . Util::backquote($GLOBALS['cfgRelation']['navigationhiding']);
-        $sqlQuery = "DELETE FROM " . $navTable
-            . " WHERE"
+            . '.' . Util::backquote($GLOBALS['cfgRelation']['navigationhiding']);
+        $sqlQuery = 'DELETE FROM ' . $navTable
+            . ' WHERE'
             . " `username`='"
             . $this->dbi->escapeString($GLOBALS['cfg']['Server']['user']) . "'"
             . " AND `item_name`='" . $this->dbi->escapeString($itemName) . "'"
@@ -195,7 +195,7 @@ class Navigation
             . " AND `db_name`='" . $this->dbi->escapeString($dbName) . "'"
             . (! empty($tableName)
                 ? " AND `table_name`='" . $this->dbi->escapeString($tableName) . "'"
-                : ""
+                : ''
             );
         $this->relation->queryAsControlUser($sqlQuery, false);
     }
@@ -239,8 +239,8 @@ class Navigation
     private function getHiddenItems(string $database, ?string $table): array
     {
         $navTable = Util::backquote($GLOBALS['cfgRelation']['db'])
-            . "." . Util::backquote($GLOBALS['cfgRelation']['navigationhiding']);
-        $sqlQuery = "SELECT `item_name`, `item_type` FROM " . $navTable
+            . '.' . Util::backquote($GLOBALS['cfgRelation']['navigationhiding']);
+        $sqlQuery = 'SELECT `item_name`, `item_type` FROM ' . $navTable
             . " WHERE `username`='"
             . $this->dbi->escapeString($GLOBALS['cfg']['Server']['user']) . "'"
             . " AND `db_name`='" . $this->dbi->escapeString($database) . "'"
diff --git a/libraries/classes/Navigation/NavigationTree.php b/libraries/classes/Navigation/NavigationTree.php
index d136631a2a..8694e32330 100644
--- a/libraries/classes/Navigation/NavigationTree.php
+++ b/libraries/classes/Navigation/NavigationTree.php
@@ -200,14 +200,14 @@ class NavigationTree
             $dbSeparator = $this->dbi->escapeString(
                 $GLOBALS['cfg']['NavigationTreeDbSeparator']
             );
-            $query = "SELECT (COUNT(DB_first_level) DIV %d) * %d ";
-            $query .= "from ( ";
-            $query .= " SELECT distinct SUBSTRING_INDEX(SCHEMA_NAME, ";
+            $query = 'SELECT (COUNT(DB_first_level) DIV %d) * %d ';
+            $query .= 'from ( ';
+            $query .= ' SELECT distinct SUBSTRING_INDEX(SCHEMA_NAME, ';
             $query .= " '%s', 1) ";
-            $query .= " DB_first_level ";
-            $query .= " FROM INFORMATION_SCHEMA.SCHEMATA ";
+            $query .= ' DB_first_level ';
+            $query .= ' FROM INFORMATION_SCHEMA.SCHEMATA ';
             $query .= " WHERE `SCHEMA_NAME` < '%s' ";
-            $query .= ") t ";
+            $query .= ') t ';
 
             $retval = $this->dbi->fetchValue(
                 sprintf(
@@ -224,7 +224,7 @@ class NavigationTree
 
         $prefixMap = [];
         if ($GLOBALS['dbs_to_test'] === false) {
-            $handle = $this->dbi->tryQuery("SHOW DATABASES");
+            $handle = $this->dbi->tryQuery('SHOW DATABASES');
             if ($handle !== false) {
                 while ($arr = $this->dbi->fetchArray($handle)) {
                     if (strcasecmp($arr[0], $GLOBALS['db']) >= 0) {
@@ -854,7 +854,7 @@ class NavigationTree
             }
             foreach ($prefixes as $key => $value) {
                 $this->groupNode($groups[$key]);
-                $groups[$key]->classes = "navGroup";
+                $groups[$key]->classes = 'navGroup';
             }
         }
     }
@@ -997,18 +997,18 @@ class NavigationTree
         if (isset($paths['aPath_clean'][2])) {
             $retval .= "<span class='hide pos2_name'>";
             $retval .= $paths['aPath_clean'][2];
-            $retval .= "</span>";
+            $retval .= '</span>';
             $retval .= "<span class='hide pos2_value'>";
             $retval .= htmlspecialchars((string) $node->pos2);
-            $retval .= "</span>";
+            $retval .= '</span>';
         }
         if (isset($paths['aPath_clean'][4])) {
             $retval .= "<span class='hide pos3_name'>";
             $retval .= $paths['aPath_clean'][4];
-            $retval .= "</span>";
+            $retval .= '</span>';
             $retval .= "<span class='hide pos3_value'>";
             $retval .= htmlspecialchars((string) $node->pos3);
-            $retval .= "</span>";
+            $retval .= '</span>';
         }
 
         return $retval;
@@ -1089,9 +1089,9 @@ class NavigationTree
                 if ($class == 'first') {
                     $iClass = " class='first'";
                 }
-                $retval .= "<i$iClass></i>";
+                $retval .= '<i' . $iClass . '></i>';
                 if (strpos($class, 'last') === false) {
-                    $retval .= "<b></b>";
+                    $retval .= '<b></b>';
                 }
 
                 $match = $this->findTreeMatch(
@@ -1103,13 +1103,13 @@ class NavigationTree
                 $retval .= " href='#'>";
                 $retval .= "<span class='hide aPath'>";
                 $retval .= $paths['aPath'];
-                $retval .= "</span>";
+                $retval .= '</span>';
                 $retval .= "<span class='hide vPath'>";
                 $retval .= $paths['vPath'];
-                $retval .= "</span>";
+                $retval .= '</span>';
                 $retval .= "<span class='hide pos'>";
                 $retval .= $this->pos;
-                $retval .= "</span>";
+                $retval .= '</span>';
                 $retval .= $this->getPaginationParamsHtml($node);
                 if ($GLOBALS['cfg']['ShowDatabasesNavigationAsTree']
                     || $parentName != 'root'
@@ -1117,17 +1117,17 @@ class NavigationTree
                     $retval .= $node->getIcon($match);
                 }
 
-                $retval .= "</a>";
-                $retval .= "</div>";
+                $retval .= '</a>';
+                $retval .= '</div>';
             } else {
                 $retval .= "<div class='block'>";
                 $iClass = '';
                 if ($class == 'first') {
                     $iClass = " class='first'";
                 }
-                $retval .= "<i$iClass></i>";
+                $retval .= '<i' . $iClass . '></i>';
                 $retval .= $this->getPaginationParamsHtml($node);
-                $retval .= "</div>";
+                $retval .= '</div>';
             }
 
             $linkClass = '';
@@ -1147,7 +1147,7 @@ class NavigationTree
             }
 
             if ($node->type == Node::CONTAINER) {
-                $retval .= "<i>";
+                $retval .= '<i>';
             }
 
             $divClass = '';
@@ -1178,16 +1178,16 @@ class NavigationTree
                 foreach ($icons as $key => $icon) {
                     $link = vsprintf($iconLinks[$key], $args);
                     if ($linkClass != '') {
-                        $retval .= "<a class='$linkClass' href='$link'>";
-                        $retval .= "{$icon}</a>";
+                        $retval .= "<a class='" . $linkClass . "' href='" . $link . "'>";
+                        $retval .= '' . $icon . '</a>';
                     } else {
-                        $retval .= "<a href='$link'>{$icon}</a>";
+                        $retval .= "<a href='" . $link . "'>" . $icon . '</a>';
                     }
                 }
             } else {
-                $retval .= "<u>{$node->icon}</u>";
+                $retval .= '<u>' . $node->icon . '</u>';
             }
-            $retval .= "</div>";
+            $retval .= '</div>';
 
             if (isset($node->links['text'])) {
                 $args = [];
@@ -1197,21 +1197,21 @@ class NavigationTree
                 $link = vsprintf($node->links['text'], $args);
                 $title = isset($node->links['title']) ? $node->links['title'] : '';
                 if ($node->type == Node::CONTAINER) {
-                    $retval .= "&nbsp;<a class='hover_show_full' href='$link'>";
+                    $retval .= "&nbsp;<a class='hover_show_full' href='" . $link . "'>";
                     $retval .= htmlspecialchars($node->name);
-                    $retval .= "</a>";
+                    $retval .= '</a>';
                 } else {
-                    $retval .= "<a class='hover_show_full$linkClass' href='$link'";
-                    $retval .= " title='$title'>";
+                    $retval .= "<a class='hover_show_full" . $linkClass . "' href='" . $link . "'";
+                    $retval .= " title='" . $title . "'>";
                     $retval .= htmlspecialchars($node->displayName ?? $node->realName);
-                    $retval .= "</a>";
+                    $retval .= '</a>';
                 }
             } else {
-                $retval .= "&nbsp;{$node->name}";
+                $retval .= '&nbsp;' . $node->name . '';
             }
             $retval .= $node->getHtmlForControlButtons();
             if ($node->type == Node::CONTAINER) {
-                $retval .= "</i>";
+                $retval .= '</i>';
             }
             $retval .= '<div class="clearfloat"></div>';
             $wrap = true;
@@ -1248,18 +1248,18 @@ class NavigationTree
             }
             if (! empty($buffer)) {
                 if ($wrap) {
-                    $retval .= "<div$hide class='list_container'><ul>";
+                    $retval .= '<div' . $hide . " class='list_container'><ul>";
                 }
                 $retval .= $this->fastFilterHtml($node);
                 $retval .= $this->getPageSelector($node);
                 $retval .= $buffer;
                 if ($wrap) {
-                    $retval .= "</ul></div>";
+                    $retval .= '</ul></div>';
                 }
             }
         }
         if ($node->hasSiblings()) {
-            $retval .= "</li>";
+            $retval .= '</li>';
         }
 
         return $retval;
@@ -1388,11 +1388,11 @@ class NavigationTree
             $retval .= '<input class="searchClause" type="text"';
             $retval .= ' name="searchClause" accesskey="q"';
             $retval .= " placeholder='"
-                . __("Type to filter these, Enter to search all");
+                . __('Type to filter these, Enter to search all');
             $retval .= "'>";
             $retval .= '<span title="' . __('Clear fast filter') . '">X</span>';
-            $retval .= "</form>";
-            $retval .= "</li>";
+            $retval .= '</form>';
+            $retval .= '</li>';
 
             return $retval;
         }
@@ -1420,10 +1420,10 @@ class NavigationTree
             $retval .= "<input class='searchClause' type='text'";
             $retval .= " name='searchClause2'";
             $retval .= " placeholder='"
-                . __("Type to filter these, Enter to search all") . "'>";
+                . __('Type to filter these, Enter to search all') . "'>";
             $retval .= "<span title='" . __('Clear fast filter') . "'>X</span>";
-            $retval .= "</form>";
-            $retval .= "</li>";
+            $retval .= '</form>';
+            $retval .= '</li>';
         }
 
         return $retval;
diff --git a/libraries/classes/Navigation/Nodes/Node.php b/libraries/classes/Navigation/Nodes/Node.php
index c9f2ac44f6..1b8802fa93 100644
--- a/libraries/classes/Navigation/Nodes/Node.php
+++ b/libraries/classes/Navigation/Nodes/Node.php
@@ -32,12 +32,12 @@ class Node
      * @var string A non-unique identifier for the node
      *             This may be trimmed when grouping nodes
      */
-    public $name = "";
+    public $name = '';
     /**
      * @var string A non-unique identifier for the node
      *             This will never change after being assigned
      */
-    public $realName = "";
+    public $realName = '';
     /**
      * @var int May be one of CONTAINER or OBJECT
      */
@@ -372,11 +372,11 @@ class Node
             if (isset($GLOBALS['cfg']['Server']['DisableIS'])
                 && ! $GLOBALS['cfg']['Server']['DisableIS']
             ) {
-                $query = "SELECT `SCHEMA_NAME` ";
-                $query .= "FROM `INFORMATION_SCHEMA`.`SCHEMATA` ";
+                $query = 'SELECT `SCHEMA_NAME` ';
+                $query .= 'FROM `INFORMATION_SCHEMA`.`SCHEMATA` ';
                 $query .= $this->getWhereClause('SCHEMA_NAME', $searchClause);
-                $query .= "ORDER BY `SCHEMA_NAME` ";
-                $query .= "LIMIT $pos, $maxItems";
+                $query .= 'ORDER BY `SCHEMA_NAME` ';
+                $query .= 'LIMIT ' . $pos . ', ' . $maxItems;
                 $retval = $GLOBALS['dbi']->fetchResult($query);
 
                 return $retval;
@@ -384,7 +384,7 @@ class Node
 
             if ($GLOBALS['dbs_to_test'] === false) {
                 $retval = [];
-                $query = "SHOW DATABASES ";
+                $query = 'SHOW DATABASES ';
                 $query .= $this->getWhereClause('Database', $searchClause);
                 $handle = $GLOBALS['dbi']->tryQuery($query);
                 if ($handle === false) {
@@ -441,33 +441,33 @@ class Node
         if (isset($GLOBALS['cfg']['Server']['DisableIS'])
             && ! $GLOBALS['cfg']['Server']['DisableIS']
         ) {
-            $query = "SELECT `SCHEMA_NAME` ";
-            $query .= "FROM `INFORMATION_SCHEMA`.`SCHEMATA`, ";
-            $query .= "(";
-            $query .= "SELECT DB_first_level ";
-            $query .= "FROM ( ";
-            $query .= "SELECT DISTINCT SUBSTRING_INDEX(SCHEMA_NAME, ";
+            $query = 'SELECT `SCHEMA_NAME` ';
+            $query .= 'FROM `INFORMATION_SCHEMA`.`SCHEMATA`, ';
+            $query .= '(';
+            $query .= 'SELECT DB_first_level ';
+            $query .= 'FROM ( ';
+            $query .= 'SELECT DISTINCT SUBSTRING_INDEX(SCHEMA_NAME, ';
             $query .= "'" . $GLOBALS['dbi']->escapeString($dbSeparator) . "', 1) ";
-            $query .= "DB_first_level ";
-            $query .= "FROM INFORMATION_SCHEMA.SCHEMATA ";
+            $query .= 'DB_first_level ';
+            $query .= 'FROM INFORMATION_SCHEMA.SCHEMATA ';
             $query .= $this->getWhereClause('SCHEMA_NAME', $searchClause);
-            $query .= ") t ";
-            $query .= "ORDER BY DB_first_level ASC ";
-            $query .= "LIMIT $pos, $maxItems";
-            $query .= ") t2 ";
+            $query .= ') t ';
+            $query .= 'ORDER BY DB_first_level ASC ';
+            $query .= 'LIMIT ' . $pos . ', ' . $maxItems;
+            $query .= ') t2 ';
             $query .= $this->getWhereClause('SCHEMA_NAME', $searchClause);
-            $query .= "AND 1 = LOCATE(CONCAT(DB_first_level, ";
+            $query .= 'AND 1 = LOCATE(CONCAT(DB_first_level, ';
             $query .= "'" . $GLOBALS['dbi']->escapeString($dbSeparator) . "'), ";
-            $query .= "CONCAT(SCHEMA_NAME, ";
+            $query .= 'CONCAT(SCHEMA_NAME, ';
             $query .= "'" . $GLOBALS['dbi']->escapeString($dbSeparator) . "')) ";
-            $query .= "ORDER BY SCHEMA_NAME ASC";
+            $query .= 'ORDER BY SCHEMA_NAME ASC';
             $retval = $GLOBALS['dbi']->fetchResult($query);
 
             return $retval;
         }
 
         if ($GLOBALS['dbs_to_test'] === false) {
-            $query = "SHOW DATABASES ";
+            $query = 'SHOW DATABASES ';
             $query .= $this->getWhereClause('Database', $searchClause);
             $handle = $GLOBALS['dbi']->tryQuery($query);
             $prefixes = [];
@@ -487,9 +487,9 @@ class Node
                 $prefixes = array_slice(array_keys($prefixMap), (int) $pos);
             }
 
-            $query = "SHOW DATABASES ";
+            $query = 'SHOW DATABASES ';
             $query .= $this->getWhereClause('Database', $searchClause);
-            $query .= "AND (";
+            $query .= 'AND (';
             $subClauses = [];
             foreach ($prefixes as $prefix) {
                 $subClauses[] = " LOCATE('"
@@ -497,7 +497,7 @@ class Node
                     . "', "
                     . "CONCAT(`Database`, '" . $dbSeparator . "')) = 1 ";
             }
-            $query .= implode("OR", $subClauses) . ")";
+            $query .= implode('OR', $subClauses) . ')';
             $retval = $GLOBALS['dbi']->fetchResult($query);
 
             return $retval;
@@ -579,8 +579,8 @@ class Node
             if (isset($GLOBALS['cfg']['Server']['DisableIS'])
                 && ! $GLOBALS['cfg']['Server']['DisableIS']
             ) {
-                $query = "SELECT COUNT(*) ";
-                $query .= "FROM INFORMATION_SCHEMA.SCHEMATA ";
+                $query = 'SELECT COUNT(*) ';
+                $query .= 'FROM INFORMATION_SCHEMA.SCHEMATA ';
                 $query .= $this->getWhereClause('SCHEMA_NAME', $searchClause);
                 $retval = (int) $GLOBALS['dbi']->fetchValue($query);
 
@@ -588,7 +588,7 @@ class Node
             }
 
             if ($GLOBALS['dbs_to_test'] === false) {
-                $query = "SHOW DATABASES ";
+                $query = 'SHOW DATABASES ';
                 $query .= $this->getWhereClause('Database', $searchClause);
                 $retval = $GLOBALS['dbi']->numRows(
                     $GLOBALS['dbi']->tryQuery($query)
@@ -610,14 +610,14 @@ class Node
 
         $dbSeparator = $GLOBALS['cfg']['NavigationTreeDbSeparator'];
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
-            $query = "SELECT COUNT(*) ";
-            $query .= "FROM ( ";
-            $query .= "SELECT DISTINCT SUBSTRING_INDEX(SCHEMA_NAME, ";
-            $query .= "'$dbSeparator', 1) ";
-            $query .= "DB_first_level ";
-            $query .= "FROM INFORMATION_SCHEMA.SCHEMATA ";
+            $query = 'SELECT COUNT(*) ';
+            $query .= 'FROM ( ';
+            $query .= 'SELECT DISTINCT SUBSTRING_INDEX(SCHEMA_NAME, ';
+            $query .= "'" . $dbSeparator . "', 1) ";
+            $query .= 'DB_first_level ';
+            $query .= 'FROM INFORMATION_SCHEMA.SCHEMATA ';
             $query .= $this->getWhereClause('SCHEMA_NAME', $searchClause);
-            $query .= ") t ";
+            $query .= ') t ';
             $retval = (int) $GLOBALS['dbi']->fetchValue($query);
 
             return $retval;
@@ -649,7 +649,7 @@ class Node
         }
 
         $prefixMap = [];
-        $query = "SHOW DATABASES ";
+        $query = 'SHOW DATABASES ';
         $query .= $this->getWhereClause('Database', $searchClause);
         $handle = $GLOBALS['dbi']->tryQuery($query);
         if ($handle !== false) {
@@ -694,7 +694,7 @@ class Node
         $databases = [];
         if (! empty($searchClause)) {
             $databases = [
-                "%" . $GLOBALS['dbi']->escapeString($searchClause) . "%",
+                '%' . $GLOBALS['dbi']->escapeString($searchClause) . '%',
             ];
         } elseif (! empty($GLOBALS['cfg']['Server']['only_db'])) {
             $databases = $GLOBALS['cfg']['Server']['only_db'];
@@ -717,16 +717,16 @@ class Node
      */
     private function getWhereClause($columnName, $searchClause = '')
     {
-        $whereClause = "WHERE TRUE ";
+        $whereClause = 'WHERE TRUE ';
         if (! empty($searchClause)) {
-            $whereClause .= "AND " . Util::backquote($columnName)
+            $whereClause .= 'AND ' . Util::backquote($columnName)
                 . " LIKE '%";
             $whereClause .= $GLOBALS['dbi']->escapeString($searchClause);
             $whereClause .= "%' ";
         }
 
         if (! empty($GLOBALS['cfg']['Server']['hide_db'])) {
-            $whereClause .= "AND " . Util::backquote($columnName)
+            $whereClause .= 'AND ' . Util::backquote($columnName)
                 . " NOT REGEXP '"
                 . $GLOBALS['dbi']->escapeString($GLOBALS['cfg']['Server']['hide_db'])
                 . "' ";
@@ -738,14 +738,14 @@ class Node
                     $GLOBALS['cfg']['Server']['only_db'],
                 ];
             }
-            $whereClause .= "AND (";
+            $whereClause .= 'AND (';
             $subClauses = [];
             foreach ($GLOBALS['cfg']['Server']['only_db'] as $eachOnlyDb) {
-                $subClauses[] = " " . Util::backquote($columnName)
+                $subClauses[] = ' ' . Util::backquote($columnName)
                     . " LIKE '"
                     . $GLOBALS['dbi']->escapeString($eachOnlyDb) . "' ";
             }
-            $whereClause .= implode("OR", $subClauses) . ") ";
+            $whereClause .= implode('OR', $subClauses) . ') ';
         }
 
         return $whereClause;
@@ -818,15 +818,15 @@ class Node
         $cfgRelation = $this->relation->getRelationsParam();
         if ($cfgRelation['navwork']) {
             $navTable = Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote(
+                . '.' . Util::backquote(
                     $cfgRelation['navigationhiding']
                 );
-            $sqlQuery = "SELECT `db_name`, COUNT(*) AS `count` FROM " . $navTable
+            $sqlQuery = 'SELECT `db_name`, COUNT(*) AS `count` FROM ' . $navTable
                 . " WHERE `username`='"
                 . $GLOBALS['dbi']->escapeString(
                     $GLOBALS['cfg']['Server']['user']
                 ) . "'"
-                . " GROUP BY `db_name`";
+                . ' GROUP BY `db_name`';
             $counts = $GLOBALS['dbi']->fetchResult(
                 $sqlQuery,
                 'db_name',
diff --git a/libraries/classes/Navigation/Nodes/NodeDatabase.php b/libraries/classes/Navigation/Nodes/NodeDatabase.php
index b3793a31d7..6faf19d9f2 100644
--- a/libraries/classes/Navigation/Nodes/NodeDatabase.php
+++ b/libraries/classes/Navigation/Nodes/NodeDatabase.php
@@ -121,12 +121,12 @@ class NodeDatabase extends Node
 
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
             $db     = $GLOBALS['dbi']->escapeString($db);
-            $query  = "SELECT COUNT(*) ";
-            $query .= "FROM `INFORMATION_SCHEMA`.`TABLES` ";
-            $query .= "WHERE `TABLE_SCHEMA`='$db' ";
-            $query .= "AND `TABLE_TYPE`" . $condition . "('BASE TABLE', 'SYSTEM VERSIONED') ";
+            $query  = 'SELECT COUNT(*) ';
+            $query .= 'FROM `INFORMATION_SCHEMA`.`TABLES` ';
+            $query .= "WHERE `TABLE_SCHEMA`='" . $db . "' ";
+            $query .= 'AND `TABLE_TYPE`' . $condition . "('BASE TABLE', 'SYSTEM VERSIONED') ";
             if (! empty($searchClause)) {
-                $query .= "AND " . $this->getWhereClauseForSearch(
+                $query .= 'AND ' . $this->getWhereClauseForSearch(
                     $searchClause,
                     $singleItem,
                     'TABLE_NAME'
@@ -134,11 +134,11 @@ class NodeDatabase extends Node
             }
             $retval = (int) $GLOBALS['dbi']->fetchValue($query);
         } else {
-            $query = "SHOW FULL TABLES FROM ";
+            $query = 'SHOW FULL TABLES FROM ';
             $query .= Util::backquote($db);
-            $query .= " WHERE `Table_type`" . $condition . "('BASE TABLE', 'SYSTEM VERSIONED') ";
+            $query .= ' WHERE `Table_type`' . $condition . "('BASE TABLE', 'SYSTEM VERSIONED') ";
             if (! empty($searchClause)) {
-                $query .= "AND " . $this->getWhereClauseForSearch(
+                $query .= 'AND ' . $this->getWhereClauseForSearch(
                     $searchClause,
                     $singleItem,
                     'Tables_in_' . $db
@@ -205,13 +205,13 @@ class NodeDatabase extends Node
         $db = $this->realName;
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
             $db = $GLOBALS['dbi']->escapeString($db);
-            $query = "SELECT COUNT(*) ";
-            $query .= "FROM `INFORMATION_SCHEMA`.`ROUTINES` ";
-            $query .= "WHERE `ROUTINE_SCHEMA` "
-                . Util::getCollateForIS() . "='$db'";
+            $query = 'SELECT COUNT(*) ';
+            $query .= 'FROM `INFORMATION_SCHEMA`.`ROUTINES` ';
+            $query .= 'WHERE `ROUTINE_SCHEMA` '
+                . Util::getCollateForIS() . "='" . $db . "'";
             $query .= "AND `ROUTINE_TYPE`='PROCEDURE' ";
             if (! empty($searchClause)) {
-                $query .= "AND " . $this->getWhereClauseForSearch(
+                $query .= 'AND ' . $this->getWhereClauseForSearch(
                     $searchClause,
                     $singleItem,
                     'ROUTINE_NAME'
@@ -220,9 +220,9 @@ class NodeDatabase extends Node
             $retval = (int) $GLOBALS['dbi']->fetchValue($query);
         } else {
             $db = $GLOBALS['dbi']->escapeString($db);
-            $query = "SHOW PROCEDURE STATUS WHERE `Db`='$db' ";
+            $query = "SHOW PROCEDURE STATUS WHERE `Db`='" . $db . "' ";
             if (! empty($searchClause)) {
-                $query .= "AND " . $this->getWhereClauseForSearch(
+                $query .= 'AND ' . $this->getWhereClauseForSearch(
                     $searchClause,
                     $singleItem,
                     'Name'
@@ -251,13 +251,13 @@ class NodeDatabase extends Node
         $db = $this->realName;
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
             $db = $GLOBALS['dbi']->escapeString($db);
-            $query = "SELECT COUNT(*) ";
-            $query .= "FROM `INFORMATION_SCHEMA`.`ROUTINES` ";
-            $query .= "WHERE `ROUTINE_SCHEMA` "
-                . Util::getCollateForIS() . "='$db' ";
+            $query = 'SELECT COUNT(*) ';
+            $query .= 'FROM `INFORMATION_SCHEMA`.`ROUTINES` ';
+            $query .= 'WHERE `ROUTINE_SCHEMA` '
+                . Util::getCollateForIS() . "='" . $db . "' ";
             $query .= "AND `ROUTINE_TYPE`='FUNCTION' ";
             if (! empty($searchClause)) {
-                $query .= "AND " . $this->getWhereClauseForSearch(
+                $query .= 'AND ' . $this->getWhereClauseForSearch(
                     $searchClause,
                     $singleItem,
                     'ROUTINE_NAME'
@@ -266,9 +266,9 @@ class NodeDatabase extends Node
             $retval = (int) $GLOBALS['dbi']->fetchValue($query);
         } else {
             $db = $GLOBALS['dbi']->escapeString($db);
-            $query = "SHOW FUNCTION STATUS WHERE `Db`='$db' ";
+            $query = "SHOW FUNCTION STATUS WHERE `Db`='" . $db . "' ";
             if (! empty($searchClause)) {
-                $query .= "AND " . $this->getWhereClauseForSearch(
+                $query .= 'AND ' . $this->getWhereClauseForSearch(
                     $searchClause,
                     $singleItem,
                     'Name'
@@ -297,12 +297,12 @@ class NodeDatabase extends Node
         $db = $this->realName;
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
             $db = $GLOBALS['dbi']->escapeString($db);
-            $query = "SELECT COUNT(*) ";
-            $query .= "FROM `INFORMATION_SCHEMA`.`EVENTS` ";
-            $query .= "WHERE `EVENT_SCHEMA` "
-                . Util::getCollateForIS() . "='$db' ";
+            $query = 'SELECT COUNT(*) ';
+            $query .= 'FROM `INFORMATION_SCHEMA`.`EVENTS` ';
+            $query .= 'WHERE `EVENT_SCHEMA` '
+                . Util::getCollateForIS() . "='" . $db . "' ";
             if (! empty($searchClause)) {
-                $query .= "AND " . $this->getWhereClauseForSearch(
+                $query .= 'AND ' . $this->getWhereClauseForSearch(
                     $searchClause,
                     $singleItem,
                     'EVENT_NAME'
@@ -311,9 +311,9 @@ class NodeDatabase extends Node
             $retval = (int) $GLOBALS['dbi']->fetchValue($query);
         } else {
             $db = Util::backquote($db);
-            $query = "SHOW EVENTS FROM $db ";
+            $query = 'SHOW EVENTS FROM ' . $db . ' ';
             if (! empty($searchClause)) {
-                $query .= "WHERE " . $this->getWhereClauseForSearch(
+                $query .= 'WHERE ' . $this->getWhereClauseForSearch(
                     $searchClause,
                     $singleItem,
                     'Name'
@@ -343,10 +343,10 @@ class NodeDatabase extends Node
     ) {
         $query = '';
         if ($singleItem) {
-            $query .= Util::backquote($columnName) . " = ";
+            $query .= Util::backquote($columnName) . ' = ';
             $query .= "'" . $GLOBALS['dbi']->escapeString($searchClause) . "'";
         } else {
-            $query .= Util::backquote($columnName) . " LIKE ";
+            $query .= Util::backquote($columnName) . ' LIKE ';
             $query .= "'%" . $GLOBALS['dbi']->escapeString($searchClause)
                 . "%'";
         }
@@ -419,8 +419,8 @@ class NodeDatabase extends Node
             return [];
         }
         $navTable = Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['navigationhiding']);
-        $sqlQuery = "SELECT `item_name` FROM " . $navTable
+            . '.' . Util::backquote($cfgRelation['navigationhiding']);
+        $sqlQuery = 'SELECT `item_name` FROM ' . $navTable
             . " WHERE `username`='" . $cfgRelation['user'] . "'"
             . " AND `item_type`='" . $type
             . "' AND `db_name`='" . $GLOBALS['dbi']->escapeString($db)
@@ -458,25 +458,25 @@ class NodeDatabase extends Node
         $db       = $this->realName;
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
             $escdDb = $GLOBALS['dbi']->escapeString($db);
-            $query  = "SELECT `TABLE_NAME` AS `name` ";
-            $query .= "FROM `INFORMATION_SCHEMA`.`TABLES` ";
-            $query .= "WHERE `TABLE_SCHEMA`='$escdDb' ";
-            $query .= "AND `TABLE_TYPE`" . $condition . "('BASE TABLE', 'SYSTEM VERSIONED') ";
+            $query  = 'SELECT `TABLE_NAME` AS `name` ';
+            $query .= 'FROM `INFORMATION_SCHEMA`.`TABLES` ';
+            $query .= "WHERE `TABLE_SCHEMA`='" . $escdDb . "' ";
+            $query .= 'AND `TABLE_TYPE`' . $condition . "('BASE TABLE', 'SYSTEM VERSIONED') ";
             if (! empty($searchClause)) {
                 $query .= "AND `TABLE_NAME` LIKE '%";
                 $query .= $GLOBALS['dbi']->escapeString($searchClause);
                 $query .= "%'";
             }
-            $query .= "ORDER BY `TABLE_NAME` ASC ";
-            $query .= "LIMIT " . intval($pos) . ", $maxItems";
+            $query .= 'ORDER BY `TABLE_NAME` ASC ';
+            $query .= 'LIMIT ' . intval($pos) . ', ' . $maxItems;
             $retval = $GLOBALS['dbi']->fetchResult($query);
         } else {
-            $query = " SHOW FULL TABLES FROM ";
+            $query = ' SHOW FULL TABLES FROM ';
             $query .= Util::backquote($db);
-            $query .= " WHERE `Table_type`" . $condition . "('BASE TABLE', 'SYSTEM VERSIONED') ";
+            $query .= ' WHERE `Table_type`' . $condition . "('BASE TABLE', 'SYSTEM VERSIONED') ";
             if (! empty($searchClause)) {
-                $query .= "AND " . Util::backquote(
-                    "Tables_in_" . $db
+                $query .= 'AND ' . Util::backquote(
+                    'Tables_in_' . $db
                 );
                 $query .= " LIKE '%" . $GLOBALS['dbi']->escapeString(
                     $searchClause
@@ -544,22 +544,22 @@ class NodeDatabase extends Node
         $db = $this->realName;
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
             $escdDb = $GLOBALS['dbi']->escapeString($db);
-            $query = "SELECT `ROUTINE_NAME` AS `name` ";
-            $query .= "FROM `INFORMATION_SCHEMA`.`ROUTINES` ";
-            $query .= "WHERE `ROUTINE_SCHEMA` "
-                . Util::getCollateForIS() . "='$escdDb'";
+            $query = 'SELECT `ROUTINE_NAME` AS `name` ';
+            $query .= 'FROM `INFORMATION_SCHEMA`.`ROUTINES` ';
+            $query .= 'WHERE `ROUTINE_SCHEMA` '
+                . Util::getCollateForIS() . "='" . $escdDb . "'";
             $query .= "AND `ROUTINE_TYPE`='" . $routineType . "' ";
             if (! empty($searchClause)) {
                 $query .= "AND `ROUTINE_NAME` LIKE '%";
                 $query .= $GLOBALS['dbi']->escapeString($searchClause);
                 $query .= "%'";
             }
-            $query .= "ORDER BY `ROUTINE_NAME` ASC ";
-            $query .= "LIMIT " . intval($pos) . ", $maxItems";
+            $query .= 'ORDER BY `ROUTINE_NAME` ASC ';
+            $query .= 'LIMIT ' . intval($pos) . ', ' . $maxItems;
             $retval = $GLOBALS['dbi']->fetchResult($query);
         } else {
             $escdDb = $GLOBALS['dbi']->escapeString($db);
-            $query = "SHOW " . $routineType . " STATUS WHERE `Db`='$escdDb' ";
+            $query = 'SHOW ' . $routineType . " STATUS WHERE `Db`='" . $escdDb . "' ";
             if (! empty($searchClause)) {
                 $query .= "AND `Name` LIKE '%";
                 $query .= $GLOBALS['dbi']->escapeString($searchClause);
@@ -625,21 +625,21 @@ class NodeDatabase extends Node
         $db = $this->realName;
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
             $escdDb = $GLOBALS['dbi']->escapeString($db);
-            $query = "SELECT `EVENT_NAME` AS `name` ";
-            $query .= "FROM `INFORMATION_SCHEMA`.`EVENTS` ";
-            $query .= "WHERE `EVENT_SCHEMA` "
-                . Util::getCollateForIS() . "='$escdDb' ";
+            $query = 'SELECT `EVENT_NAME` AS `name` ';
+            $query .= 'FROM `INFORMATION_SCHEMA`.`EVENTS` ';
+            $query .= 'WHERE `EVENT_SCHEMA` '
+                . Util::getCollateForIS() . "='" . $escdDb . "' ";
             if (! empty($searchClause)) {
                 $query .= "AND `EVENT_NAME` LIKE '%";
                 $query .= $GLOBALS['dbi']->escapeString($searchClause);
                 $query .= "%'";
             }
-            $query .= "ORDER BY `EVENT_NAME` ASC ";
-            $query .= "LIMIT " . intval($pos) . ", $maxItems";
+            $query .= 'ORDER BY `EVENT_NAME` ASC ';
+            $query .= 'LIMIT ' . intval($pos) . ', ' . $maxItems;
             $retval = $GLOBALS['dbi']->fetchResult($query);
         } else {
             $escdDb = Util::backquote($db);
-            $query = "SHOW EVENTS FROM $escdDb ";
+            $query = 'SHOW EVENTS FROM ' . $escdDb . ' ';
             if (! empty($searchClause)) {
                 $query .= "WHERE `Name` LIKE '%";
                 $query .= $GLOBALS['dbi']->escapeString($searchClause);
diff --git a/libraries/classes/Navigation/Nodes/NodeTable.php b/libraries/classes/Navigation/Nodes/NodeTable.php
index 58caa5af0f..02adb0a0d1 100644
--- a/libraries/classes/Navigation/Nodes/NodeTable.php
+++ b/libraries/classes/Navigation/Nodes/NodeTable.php
@@ -99,15 +99,15 @@ class NodeTable extends NodeDatabaseChild
                 if (! $GLOBALS['cfg']['Server']['DisableIS']) {
                     $db = $GLOBALS['dbi']->escapeString($db);
                     $table = $GLOBALS['dbi']->escapeString($table);
-                    $query = "SELECT COUNT(*) ";
-                    $query .= "FROM `INFORMATION_SCHEMA`.`COLUMNS` ";
-                    $query .= "WHERE `TABLE_NAME`='$table' ";
-                    $query .= "AND `TABLE_SCHEMA`='$db'";
+                    $query = 'SELECT COUNT(*) ';
+                    $query .= 'FROM `INFORMATION_SCHEMA`.`COLUMNS` ';
+                    $query .= "WHERE `TABLE_NAME`='" . $table . "' ";
+                    $query .= "AND `TABLE_SCHEMA`='" . $db . "'";
                     $retval = (int) $GLOBALS['dbi']->fetchValue($query);
                 } else {
                     $db = Util::backquote($db);
                     $table = Util::backquote($table);
-                    $query = "SHOW COLUMNS FROM $table FROM $db";
+                    $query = 'SHOW COLUMNS FROM ' . $table . ' FROM ' . $db . '';
                     $retval = (int) $GLOBALS['dbi']->numRows(
                         $GLOBALS['dbi']->tryQuery($query)
                     );
@@ -116,7 +116,7 @@ class NodeTable extends NodeDatabaseChild
             case 'indexes':
                 $db = Util::backquote($db);
                 $table = Util::backquote($table);
-                $query = "SHOW INDEXES FROM $table FROM $db";
+                $query = 'SHOW INDEXES FROM ' . $table . ' FROM ' . $db;
                 $retval = (int) $GLOBALS['dbi']->numRows(
                     $GLOBALS['dbi']->tryQuery($query)
                 );
@@ -125,17 +125,17 @@ class NodeTable extends NodeDatabaseChild
                 if (! $GLOBALS['cfg']['Server']['DisableIS']) {
                     $db = $GLOBALS['dbi']->escapeString($db);
                     $table = $GLOBALS['dbi']->escapeString($table);
-                    $query = "SELECT COUNT(*) ";
-                    $query .= "FROM `INFORMATION_SCHEMA`.`TRIGGERS` ";
-                    $query .= "WHERE `EVENT_OBJECT_SCHEMA` "
-                    . Util::getCollateForIS() . "='$db' ";
-                    $query .= "AND `EVENT_OBJECT_TABLE` "
-                    . Util::getCollateForIS() . "='$table'";
+                    $query = 'SELECT COUNT(*) ';
+                    $query .= 'FROM `INFORMATION_SCHEMA`.`TRIGGERS` ';
+                    $query .= 'WHERE `EVENT_OBJECT_SCHEMA` '
+                    . Util::getCollateForIS() . "='" . $db . "' ";
+                    $query .= 'AND `EVENT_OBJECT_TABLE` '
+                    . Util::getCollateForIS() . "='" . $table . "'";
                     $retval = (int) $GLOBALS['dbi']->fetchValue($query);
                 } else {
                     $db = Util::backquote($db);
                     $table = $GLOBALS['dbi']->escapeString($table);
-                    $query = "SHOW TRIGGERS FROM $db WHERE `Table` = '$table'";
+                    $query = 'SHOW TRIGGERS FROM ' . $db . " WHERE `Table` = '" . $table . "'";
                     $retval = (int) $GLOBALS['dbi']->numRows(
                         $GLOBALS['dbi']->tryQuery($query)
                     );
@@ -171,23 +171,23 @@ class NodeTable extends NodeDatabaseChild
                 if (! $GLOBALS['cfg']['Server']['DisableIS']) {
                     $db = $GLOBALS['dbi']->escapeString($db);
                     $table = $GLOBALS['dbi']->escapeString($table);
-                    $query = "SELECT `COLUMN_NAME` AS `name` ";
-                    $query .= ",`COLUMN_KEY` AS `key` ";
-                    $query .= ",`DATA_TYPE` AS `type` ";
-                    $query .= ",`COLUMN_DEFAULT` AS `default` ";
+                    $query = 'SELECT `COLUMN_NAME` AS `name` ';
+                    $query .= ',`COLUMN_KEY` AS `key` ';
+                    $query .= ',`DATA_TYPE` AS `type` ';
+                    $query .= ',`COLUMN_DEFAULT` AS `default` ';
                     $query .= ",IF (`IS_NULLABLE` = 'NO', '', 'nullable') AS `nullable` ";
-                    $query .= "FROM `INFORMATION_SCHEMA`.`COLUMNS` ";
-                    $query .= "WHERE `TABLE_NAME`='$table' ";
-                    $query .= "AND `TABLE_SCHEMA`='$db' ";
-                    $query .= "ORDER BY `COLUMN_NAME` ASC ";
-                    $query .= "LIMIT " . intval($pos) . ", $maxItems";
+                    $query .= 'FROM `INFORMATION_SCHEMA`.`COLUMNS` ';
+                    $query .= "WHERE `TABLE_NAME`='" . $table . "' ";
+                    $query .= "AND `TABLE_SCHEMA`='" . $db . "' ";
+                    $query .= 'ORDER BY `COLUMN_NAME` ASC ';
+                    $query .= 'LIMIT ' . intval($pos) . ', ' . $maxItems;
                     $retval = $GLOBALS['dbi']->fetchResult($query);
                     break;
                 }
 
                 $db = Util::backquote($db);
                 $table = Util::backquote($table);
-                $query = "SHOW COLUMNS FROM $table FROM $db";
+                $query = 'SHOW COLUMNS FROM ' . $table . ' FROM ' . $db;
                 $handle = $GLOBALS['dbi']->tryQuery($query);
                 if ($handle === false) {
                     break;
@@ -208,7 +208,7 @@ class NodeTable extends NodeDatabaseChild
             case 'indexes':
                 $db = Util::backquote($db);
                 $table = Util::backquote($table);
-                $query = "SHOW INDEXES FROM $table FROM $db";
+                $query = 'SHOW INDEXES FROM ' . $table . ' FROM ' . $db;
                 $handle = $GLOBALS['dbi']->tryQuery($query);
                 if ($handle === false) {
                     break;
@@ -230,21 +230,21 @@ class NodeTable extends NodeDatabaseChild
                 if (! $GLOBALS['cfg']['Server']['DisableIS']) {
                     $db = $GLOBALS['dbi']->escapeString($db);
                     $table = $GLOBALS['dbi']->escapeString($table);
-                    $query = "SELECT `TRIGGER_NAME` AS `name` ";
-                    $query .= "FROM `INFORMATION_SCHEMA`.`TRIGGERS` ";
-                    $query .= "WHERE `EVENT_OBJECT_SCHEMA` "
-                    . Util::getCollateForIS() . "='$db' ";
-                    $query .= "AND `EVENT_OBJECT_TABLE` "
-                    . Util::getCollateForIS() . "='$table' ";
-                    $query .= "ORDER BY `TRIGGER_NAME` ASC ";
-                    $query .= "LIMIT " . intval($pos) . ", $maxItems";
+                    $query = 'SELECT `TRIGGER_NAME` AS `name` ';
+                    $query .= 'FROM `INFORMATION_SCHEMA`.`TRIGGERS` ';
+                    $query .= 'WHERE `EVENT_OBJECT_SCHEMA` '
+                    . Util::getCollateForIS() . "='" . $db . "' ";
+                    $query .= 'AND `EVENT_OBJECT_TABLE` '
+                    . Util::getCollateForIS() . "='" . $table . "' ";
+                    $query .= 'ORDER BY `TRIGGER_NAME` ASC ';
+                    $query .= 'LIMIT ' . intval($pos) . ', ' . $maxItems;
                     $retval = $GLOBALS['dbi']->fetchResult($query);
                     break;
                 }
 
                 $db = Util::backquote($db);
                 $table = $GLOBALS['dbi']->escapeString($table);
-                $query = "SHOW TRIGGERS FROM $db WHERE `Table` = '$table'";
+                $query = 'SHOW TRIGGERS FROM ' . $db . " WHERE `Table` = '" . $table . "'";
                 $handle = $GLOBALS['dbi']->tryQuery($query);
                 if ($handle === false) {
                     break;
diff --git a/libraries/classes/Normalization.php b/libraries/classes/Normalization.php
index 17fe8dcdb6..d0651526f3 100644
--- a/libraries/classes/Normalization.php
+++ b/libraries/classes/Normalization.php
@@ -87,8 +87,8 @@ class Normalization
             null,
             true
         );
-        $type = "";
-        $selectColHtml = "";
+        $type = '';
+        $selectColHtml = '';
         foreach ($columns as $column => $def) {
             if (isset($def['Type'])) {
                 $extractedColumnSpec = Util::extractColumnSpec($def['Type']);
@@ -213,11 +213,11 @@ class Normalization
         $step = 1;
         $stepTxt = __('Make all columns atomic');
         $html = "<h3 class='text-center'>"
-            . __('First step of normalization (1NF)') . "</h3>";
+            . __('First step of normalization (1NF)') . '</h3>';
         $html .= "<div id='mainContent' data-normalizeto='" . $normalizedTo . "'>" .
-            "<fieldset>" .
-            "<legend>" . __('Step 1.') . $step . " " . $stepTxt . "</legend>" .
-            "<h4>" . __(
+            '<fieldset>' .
+            '<legend>' . __('Step 1.') . $step . ' ' . $stepTxt . '</legend>' .
+            '<h4>' . __(
                 'Do you have any column which can be split into more than'
                 . ' one column? '
                 . 'For example: address can be split into street, city, country and zip.'
@@ -226,30 +226,30 @@ class Normalization
             . "data-pick=false href='#'> "
             . __(
                 'Show me the central list of columns that are not already in this table'
-            ) . " </a>)</h4>"
+            ) . ' </a>)</h4>'
             . "<p class='cm-em'>" . __(
                 'Select a column which can be split into more '
                 . 'than one (on select of \'no such column\', it\'ll move to next step).'
             )
-            . "</p>"
+            . '</p>'
             . "<div id='extra'>"
             . "<select id='selectNonAtomicCol' name='makeAtomic'>"
             . '<option selected="selected" disabled="disabled">'
-            . __('Select one…') . "</option>"
-            . "<option value='no_such_col'>" . __('No such column') . "</option>"
+            . __('Select one…') . '</option>'
+            . "<option value='no_such_col'>" . __('No such column') . '</option>'
             . $this->getHtmlForColumnsList(
                 $db,
                 $table,
                 _pgettext('string types', 'String')
             )
-            . "</select>"
-            . "<span>" . __('split into ')
+            . '</select>'
+            . '<span>' . __('split into ')
             . "</span><input id='numField' type='number' value='2'>"
             . "<input type='submit' id='splitGo' value='" . __('Go') . "'></div>"
             . "<div id='newCols'></div>"
             . "</fieldset><fieldset class='tblFooters'>"
-            . "</fieldset>"
-            . "</div>";
+            . '</fieldset>'
+            . '</div>';
         return $html;
     }
 
@@ -266,18 +266,18 @@ class Normalization
         $step = 2;
         $stepTxt = __('Have a primary key');
         $primary = Index::getPrimary($table, $db);
-        $hasPrimaryKey = "0";
-        $legendText = __('Step 1.') . $step . " " . $stepTxt;
+        $hasPrimaryKey = '0';
+        $legendText = __('Step 1.') . $step . ' ' . $stepTxt;
         $extra = '';
         if ($primary) {
-            $headText = __("Primary key already exists.");
-            $subText = __("Taking you to next step…");
-            $hasPrimaryKey = "1";
+            $headText = __('Primary key already exists.');
+            $subText = __('Taking you to next step…');
+            $hasPrimaryKey = '1';
         } else {
             $headText = __(
-                "There is no primary key; please add one.<br>"
-                . "Hint: A primary key is a column "
-                . "(or combination of columns) that uniquely identify all rows."
+                'There is no primary key; please add one.<br>'
+                . 'Hint: A primary key is a column '
+                . '(or combination of columns) that uniquely identify all rows.'
             );
             $subText = '<a href="#" id="createPrimaryKey">'
                 . Generator::getIcon(
@@ -289,8 +289,8 @@ class Normalization
                 . '</a>';
             $extra = __(
                 "If it's not possible to make existing "
-                . "column combinations as primary key"
-            ) . "<br>"
+                . 'column combinations as primary key'
+            ) . '<br>'
                 . '<a href="#" id="addNewPrimary">'
                 . __('+ Add a new primary key column') . '</a>';
         }
@@ -315,18 +315,18 @@ class Normalization
     {
         $step = 4;
         $stepTxt = __('Remove redundant columns');
-        $legendText = __('Step 1.') . $step . " " . $stepTxt;
+        $legendText = __('Step 1.') . $step . ' ' . $stepTxt;
         $headText = __(
-            "Do you have a group of columns which on combining gives an existing"
-            . " column? For example, if you have first_name, last_name and"
-            . " full_name then combining first_name and last_name gives full_name"
-            . " which is redundant."
+            'Do you have a group of columns which on combining gives an existing'
+            . ' column? For example, if you have first_name, last_name and'
+            . ' full_name then combining first_name and last_name gives full_name'
+            . ' which is redundant.'
         );
         $subText = __(
-            "Check the columns which are redundant and click on remove. "
+            'Check the columns which are redundant and click on remove. '
             . "If no redundant column, click on 'No redundant column'"
         );
-        $extra = $this->getHtmlForColumnsList($db, $table, 'all', "checkbox") . "<br>"
+        $extra = $this->getHtmlForColumnsList($db, $table, 'all', 'checkbox') . '<br>'
             . '<input class="btn btn-secondary" type="submit" id="removeRedundant" value="'
             . __('Remove selected') . '">'
             . '<input class="btn btn-secondary" type="submit" value="' . __('No redundant column')
@@ -351,20 +351,20 @@ class Normalization
     {
         $step = 3;
         $stepTxt = __('Move repeating groups');
-        $legendText = __('Step 1.') . $step . " " . $stepTxt;
+        $legendText = __('Step 1.') . $step . ' ' . $stepTxt;
         $headText = __(
-            "Do you have a group of two or more columns that are closely "
-            . "related and are all repeating the same attribute? For example, "
-            . "a table that holds data on books might have columns such as book_id, "
-            . "author1, author2, author3 and so on which form a "
-            . "repeating group. In this case a new table (book_id, author) should "
-            . "be created."
+            'Do you have a group of two or more columns that are closely '
+            . 'related and are all repeating the same attribute? For example, '
+            . 'a table that holds data on books might have columns such as book_id, '
+            . 'author1, author2, author3 and so on which form a '
+            . 'repeating group. In this case a new table (book_id, author) should '
+            . 'be created.'
         );
         $subText = __(
-            "Check the columns which form a repeating group. "
+            'Check the columns which form a repeating group. '
             . "If no such group, click on 'No repeating group'"
         );
-        $extra = $this->getHtmlForColumnsList($db, $table, 'all', "checkbox") . "<br>"
+        $extra = $this->getHtmlForColumnsList($db, $table, 'all', 'checkbox') . '<br>'
             . '<input class="btn btn-secondary" type="submit" id="moveRepeatingGroup" value="'
             . __('Done') . '">'
             . '<input class="btn btn-secondary" type="submit" value="' . __('No repeating group')
@@ -394,13 +394,13 @@ class Normalization
      */
     public function getHtmlFor2NFstep1($db, $table)
     {
-        $legendText = __('Step 2.') . "1 " . __('Find partial dependencies');
+        $legendText = __('Step 2.') . '1 ' . __('Find partial dependencies');
         $primary = Index::getPrimary($table, $db);
         $primarycols = $primary->getColumns();
         $pk = [];
         $subText = '';
-        $selectPkForm = "";
-        $extra = "";
+        $selectPkForm = '';
+        $extra = '';
         foreach ($primarycols as $col) {
             $pk[] = $col->getName();
             $selectPkForm .= '<input type="checkbox" name="pd" value="'
@@ -450,10 +450,10 @@ class Normalization
                 foreach ($columns as $column) {
                     if (! in_array($column, $pk)) {
                         $cnt++;
-                        $extra .= "<b>" . sprintf(
+                        $extra .= '<b>' . sprintf(
                             __('\'%1$s\' depends on:'),
                             htmlspecialchars($column)
-                        ) . "</b><br>";
+                        ) . '</b><br>';
                         $extra .= '<form id="pk_' . $cnt . '" data-colname="'
                             . htmlspecialchars($column) . '" class="smallIndent">'
                             . $selectPkForm . '</form><br><br>';
@@ -600,7 +600,7 @@ class Normalization
      */
     public function getHtmlForNewTables3NF($dependencies, array $tables, $db)
     {
-        $html = "";
+        $html = '';
         $i = 1;
         $newTables = [];
         foreach ($tables as $table => $arrDependson) {
@@ -639,8 +639,8 @@ class Normalization
                             . (count($dependents) > 0 ? ', ' : '')
                             . htmlspecialchars(implode(', ', $dependents)) . ' )';
                         $newTables[$table][$tableName] = [
-                            "pk" => $key,
-                            "nonpk" => implode(', ', $dependents),
+                            'pk' => $key,
+                            'nonpk' => implode(', ', $dependents),
                         ];
                         $i++;
                         $tableName = 'table' . $i;
@@ -827,8 +827,8 @@ class Normalization
      */
     public function getHtmlFor3NFstep1($db, array $tables)
     {
-        $legendText = __('Step 3.') . "1 " . __('Find transitive dependencies');
-        $extra = "";
+        $legendText = __('Step 3.') . '1 ' . __('Find transitive dependencies');
+        $extra = '';
         $headText = __(
             'Please answer the following question(s) '
             . 'carefully to obtain a correct normalization.'
@@ -845,7 +845,7 @@ class Normalization
         foreach ($tables as $table) {
             $primary = Index::getPrimary($table, $db);
             $primarycols = $primary->getColumns();
-            $selectTdForm = "";
+            $selectTdForm = '';
             $pk = [];
             foreach ($primarycols as $col) {
                 $pk[] = $col->getName();
@@ -868,11 +868,11 @@ class Normalization
             foreach ($columns as $column) {
                 if (! in_array($column, $pk)) {
                     $cnt++;
-                    $extra .= "<b>" . sprintf(
+                    $extra .= '<b>' . sprintf(
                         __('\'%1$s\' depends on:'),
                         htmlspecialchars($column)
                     )
-                        . "</b><br>";
+                        . '</b><br>';
                     $extra .= '<form id="td_' . $cnt . '" data-colname="'
                         . htmlspecialchars($column) . '" data-tablename="'
                         . htmlspecialchars($table) . '" class="smallIndent">'
@@ -881,13 +881,13 @@ class Normalization
                 }
             }
         }
-        if ($extra == "") {
+        if ($extra == '') {
             $headText = __(
-                "No Transitive dependencies possible as the table "
+                'No Transitive dependencies possible as the table '
                 . "doesn't have any non primary key columns"
             );
-            $subText = "";
-            $extra = "<h3>" . __("Table is already in Third normal form!") . "</h3>";
+            $subText = '';
+            $extra = '<h3>' . __('Table is already in Third normal form!') . '</h3>';
         }
         return [
             'legendText' => $legendText,
@@ -931,7 +931,7 @@ class Normalization
             . "<span class='floatleft'>" . __(
                 'Hint: Please follow the procedure carefully in order '
                 . 'to obtain correct normalization'
-            ) . "</span>"
+            ) . '</span>'
             . '<input class="btn btn-primary" type="submit" name="submit_normalize" value="' . __('Go') . '">'
             . '</fieldset>'
             . '</form>'
diff --git a/libraries/classes/Operations.php b/libraries/classes/Operations.php
index 610c5636a4..d285311b9a 100644
--- a/libraries/classes/Operations.php
+++ b/libraries/classes/Operations.php
@@ -645,8 +645,8 @@ class Operations
             && $GLOBALS['is_reload_priv']
         ) {
             $this->dbi->selectDb('mysql');
-            $newname = str_replace("_", "\_", $newname);
-            $oldDb = str_replace("_", "\_", $oldDb);
+            $newname = str_replace('_', '\_', $newname);
+            $oldDb = str_replace('_', '\_', $oldDb);
 
             // For Db specific privileges
             $query_db_specific = 'UPDATE ' . Util::backquote('db')
@@ -673,7 +673,7 @@ class Operations
             $this->dbi->query($query_proc_specific);
 
             // Finally FLUSH the new privileges
-            $flush_query = "FLUSH PRIVILEGES;";
+            $flush_query = 'FLUSH PRIVILEGES;';
             $this->dbi->query($flush_query);
         }
     }
@@ -693,8 +693,8 @@ class Operations
             && $GLOBALS['is_reload_priv']
         ) {
             $this->dbi->selectDb('mysql');
-            $newname = str_replace("_", "\_", $newname);
-            $oldDb = str_replace("_", "\_", $oldDb);
+            $newname = str_replace('_', '\_', $newname);
+            $oldDb = str_replace('_', '\_', $oldDb);
 
             $query_db_specific_old = 'SELECT * FROM '
                 . Util::backquote('db') . ' WHERE '
@@ -777,7 +777,7 @@ class Operations
             }
 
             // Finally FLUSH the new privileges
-            $flush_query = "FLUSH PRIVILEGES;";
+            $flush_query = 'FLUSH PRIVILEGES;';
             $this->dbi->query($flush_query);
         }
     }
@@ -2047,7 +2047,7 @@ class Operations
             $this->dbi->query($query_col_specific);
 
             // Finally FLUSH the new privileges
-            $flush_query = "FLUSH PRIVILEGES;";
+            $flush_query = 'FLUSH PRIVILEGES;';
             $this->dbi->query($flush_query);
         }
     }
@@ -2110,7 +2110,7 @@ class Operations
             }
 
             // Finally FLUSH the new privileges
-            $flush_query = "FLUSH PRIVILEGES;";
+            $flush_query = 'FLUSH PRIVILEGES;';
             $this->dbi->query($flush_query);
         }
     }
diff --git a/libraries/classes/Partition.php b/libraries/classes/Partition.php
index 313034fc6d..05f7d656aa 100644
--- a/libraries/classes/Partition.php
+++ b/libraries/classes/Partition.php
@@ -155,7 +155,7 @@ class Partition extends SubPartition
     {
         if (Partition::havePartitioning()) {
             $result = $GLOBALS['dbi']->fetchResult(
-                "SELECT * FROM `information_schema`.`PARTITIONS`"
+                'SELECT * FROM `information_schema`.`PARTITIONS`'
                 . " WHERE `TABLE_SCHEMA` = '" . $GLOBALS['dbi']->escapeString($db)
                 . "' AND `TABLE_NAME` = '" . $GLOBALS['dbi']->escapeString($table) . "'"
             );
@@ -196,7 +196,7 @@ class Partition extends SubPartition
     {
         if (Partition::havePartitioning()) {
             return $GLOBALS['dbi']->fetchResult(
-                "SELECT DISTINCT `PARTITION_NAME` FROM `information_schema`.`PARTITIONS`"
+                'SELECT DISTINCT `PARTITION_NAME` FROM `information_schema`.`PARTITIONS`'
                 . " WHERE `TABLE_SCHEMA` = '" . $GLOBALS['dbi']->escapeString($db)
                 . "' AND `TABLE_NAME` = '" . $GLOBALS['dbi']->escapeString($table) . "'"
             );
@@ -217,10 +217,10 @@ class Partition extends SubPartition
     {
         if (Partition::havePartitioning()) {
             $partition_method = $GLOBALS['dbi']->fetchResult(
-                "SELECT `PARTITION_METHOD` FROM `information_schema`.`PARTITIONS`"
+                'SELECT `PARTITION_METHOD` FROM `information_schema`.`PARTITIONS`'
                 . " WHERE `TABLE_SCHEMA` = '" . $GLOBALS['dbi']->escapeString($db) . "'"
                 . " AND `TABLE_NAME` = '" . $GLOBALS['dbi']->escapeString($table) . "'"
-                . " LIMIT 1"
+                . ' LIMIT 1'
             );
             if (! empty($partition_method)) {
                 return $partition_method[0];
@@ -246,7 +246,7 @@ class Partition extends SubPartition
         if (! $already_checked) {
             if ($GLOBALS['dbi']->getVersion() < 50600) {
                 if ($GLOBALS['dbi']->fetchValue(
-                    "SELECT @@have_partitioning;"
+                    'SELECT @@have_partitioning;'
                 )) {
                     $have_partitioning = true;
                 }
@@ -254,7 +254,7 @@ class Partition extends SubPartition
                 $have_partitioning = true;
             } else {
                 // see https://dev.mysql.com/doc/refman/5.6/en/partitioning.html
-                $plugins = $GLOBALS['dbi']->fetchResult("SHOW PLUGINS");
+                $plugins = $GLOBALS['dbi']->fetchResult('SHOW PLUGINS');
                 foreach ($plugins as $value) {
                     if ($value['Name'] == 'partition') {
                         $have_partitioning = true;
diff --git a/libraries/classes/Plugins.php b/libraries/classes/Plugins.php
index 1c735b0742..bc727a9c94 100644
--- a/libraries/classes/Plugins.php
+++ b/libraries/classes/Plugins.php
@@ -53,7 +53,7 @@ class Plugins
             . mb_strtolower(mb_substr($plugin_type, 1))
             . mb_strtoupper($plugin_format[0])
             . mb_strtolower(mb_substr($plugin_format, 1));
-        $file = $class_name . ".php";
+        $file = $class_name . '.php';
         if (is_file($plugins_dir . $file)) {
             //include_once $plugins_dir . $file;
             $fqnClass = 'PhpMyAdmin\\' . str_replace('/', '\\', mb_substr($plugins_dir, 18)) . $class_name;
@@ -292,7 +292,7 @@ class Plugins
         $properties = null;
         if (! $is_subgroup) {
             // for subgroup headers
-            if (mb_strpos(get_class($propertyGroup), "PropertyItem")) {
+            if (mb_strpos(get_class($propertyGroup), 'PropertyItem')) {
                 $properties = [$propertyGroup];
             } else {
                 // for main groups
@@ -323,7 +323,7 @@ class Plugins
             foreach ($properties as $propertyItem) {
                 $property_class = get_class($propertyItem);
                 // if the property is a subgroup, we deal with it recursively
-                if (mb_strpos($property_class, "Subgroup")) {
+                if (mb_strpos($property_class, 'Subgroup')) {
                     // for subgroups
                     // each subgroup can have a header, which may also be a form element
                     /** @var OptionsPropertyItem $subgroup_header */
@@ -371,7 +371,7 @@ class Plugins
             }
         }
 
-        if (method_exists($propertyGroup, "getDoc")) {
+        if (method_exists($propertyGroup, 'getDoc')) {
             $doc = $propertyGroup->getDoc();
             if ($doc != null) {
                 if (count($doc) === 3) {
diff --git a/libraries/classes/Plugins/Auth/AuthenticationCookie.php b/libraries/classes/Plugins/Auth/AuthenticationCookie.php
index a24f65fd33..c90dad57e0 100644
--- a/libraries/classes/Plugins/Auth/AuthenticationCookie.php
+++ b/libraries/classes/Plugins/Auth/AuthenticationCookie.php
@@ -249,7 +249,7 @@ class AuthenticationCookie extends AuthenticationPlugin
             if (! empty($GLOBALS['cfg']['CaptchaLoginPrivateKey'])
                 && ! empty($GLOBALS['cfg']['CaptchaLoginPublicKey'])
             ) {
-                if (! empty($_POST["g-recaptcha-response"])) {
+                if (! empty($_POST['g-recaptcha-response'])) {
                     if (function_exists('curl_init')) {
                         $reCaptcha = new ReCaptcha\ReCaptcha(
                             $GLOBALS['cfg']['CaptchaLoginPrivateKey'],
@@ -269,7 +269,7 @@ class AuthenticationCookie extends AuthenticationPlugin
 
                     // verify captcha status.
                     $resp = $reCaptcha->verify(
-                        $_POST["g-recaptcha-response"],
+                        $_POST['g-recaptcha-response'],
                         Core::getIp()
                     );
 
diff --git a/libraries/classes/Plugins/Export/ExportCodegen.php b/libraries/classes/Plugins/Export/ExportCodegen.php
index 20017a06c9..82ee8d915f 100644
--- a/libraries/classes/Plugins/Export/ExportCodegen.php
+++ b/libraries/classes/Plugins/Export/ExportCodegen.php
@@ -60,15 +60,15 @@ class ExportCodegen extends ExportPlugin
     {
         $this->_setCgFormats(
             [
-                "NHibernate C# DO",
-                "NHibernate XML",
+                'NHibernate C# DO',
+                'NHibernate XML',
             ]
         );
 
         $this->_setCgHandlers(
             [
-                "_handleNHibernateCSBody",
-                "_handleNHibernateXMLBody",
+                '_handleNHibernateCSBody',
+                '_handleNHibernateXMLBody',
             ]
         );
     }
@@ -90,16 +90,16 @@ class ExportCodegen extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
-        $leaf = new HiddenPropertyItem("structure_or_data");
+        $leaf = new HiddenPropertyItem('structure_or_data');
         $generalOptions->addProperty($leaf);
         $leaf = new SelectPropertyItem(
-            "format",
+            'format',
             __('Format:')
         );
         $leaf->setValues($this->_getCgFormats());
@@ -203,7 +203,7 @@ class ExportCodegen extends ExportPlugin
             );
         }
 
-        return $this->export->outputHandler(sprintf("%s is not supported.", $format));
+        return $this->export->outputHandler(sprintf('%s is not supported.', $format));
     }
 
     /**
@@ -357,7 +357,7 @@ class ExportCodegen extends ExportPlugin
             . 'table="' . ExportCodegen::cgMakeIdentifier($table_alias) . '">';
         $result = $GLOBALS['dbi']->query(
             sprintf(
-                "DESC %s.%s",
+                'DESC %s.%s',
                 Util::backquote($db),
                 Util::backquote($table)
             )
diff --git a/libraries/classes/Plugins/Export/ExportCsv.php b/libraries/classes/Plugins/Export/ExportCsv.php
index 5995a12d5f..d4bfa38980 100644
--- a/libraries/classes/Plugins/Export/ExportCsv.php
+++ b/libraries/classes/Plugins/Export/ExportCsv.php
@@ -54,29 +54,29 @@ class ExportCsv extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create leaf items and add them to the group
         $leaf = new TextPropertyItem(
-            "separator",
+            'separator',
             __('Columns separated with:')
         );
         $generalOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "enclosed",
+            'enclosed',
             __('Columns enclosed with:')
         );
         $generalOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "escaped",
+            'escaped',
             __('Columns escaped with:')
         );
         $generalOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "terminated",
+            'terminated',
             __('Lines terminated with:')
         );
         $generalOptions->addProperty($leaf);
@@ -296,7 +296,7 @@ class ExportCsv extends ExportPlugin
                                 "\r",
                                 "\n",
                             ],
-                            "",
+                            '',
                             $row[$j]
                         );
                     }
diff --git a/libraries/classes/Plugins/Export/ExportExcel.php b/libraries/classes/Plugins/Export/ExportExcel.php
index 2c64903638..6391617c21 100644
--- a/libraries/classes/Plugins/Export/ExportExcel.php
+++ b/libraries/classes/Plugins/Export/ExportExcel.php
@@ -42,11 +42,11 @@ class ExportExcel extends ExportCsv
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
         $leaf = new TextPropertyItem(
             'null',
diff --git a/libraries/classes/Plugins/Export/ExportHtmlword.php b/libraries/classes/Plugins/Export/ExportHtmlword.php
index 255c1ca871..3468643675 100644
--- a/libraries/classes/Plugins/Export/ExportHtmlword.php
+++ b/libraries/classes/Plugins/Export/ExportHtmlword.php
@@ -57,16 +57,16 @@ class ExportHtmlword extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // what to dump (structure/data/both)
         $dumpWhat = new OptionsPropertyMainGroup(
-            "dump_what",
+            'dump_what',
             __('Dump table')
         );
         // create primary items and add them to the group
-        $leaf = new RadioPropertyItem("structure_or_data");
+        $leaf = new RadioPropertyItem('structure_or_data');
         $leaf->setValues(
             [
                 'structure'          => __('structure'),
@@ -80,18 +80,18 @@ class ExportHtmlword extends ExportPlugin
 
         // data options main group
         $dataOptions = new OptionsPropertyMainGroup(
-            "dump_what",
+            'dump_what',
             __('Data dump options')
         );
         $dataOptions->setForce('structure');
         // create primary items and add them to the group
         $leaf = new TextPropertyItem(
-            "null",
+            'null',
             __('Replace NULL with:')
         );
         $dataOptions->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "columns",
+            'columns',
             __('Put columns names in the first row')
         );
         $dataOptions->addProperty($leaf);
diff --git a/libraries/classes/Plugins/Export/ExportJson.php b/libraries/classes/Plugins/Export/ExportJson.php
index 4c0f1fb246..f4311dc391 100644
--- a/libraries/classes/Plugins/Export/ExportJson.php
+++ b/libraries/classes/Plugins/Export/ExportJson.php
@@ -77,13 +77,13 @@ class ExportJson extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
-        $leaf = new HiddenPropertyItem("structure_or_data");
+        $leaf = new HiddenPropertyItem('structure_or_data');
         $generalOptions->addProperty($leaf);
 
         $leaf = new BoolPropertyItem(
@@ -227,7 +227,7 @@ class ExportJson extends ExportPlugin
                 'type' => 'table',
                 'name' => $table_alias,
                 'database' => $db_alias,
-                'data' => "@@DATA@@",
+                'data' => '@@DATA@@',
             ]
         );
         list($header, $footer) = explode('"@@DATA@@"', $buffer);
diff --git a/libraries/classes/Plugins/Export/ExportLatex.php b/libraries/classes/Plugins/Export/ExportLatex.php
index cfcec3f114..1ef97ac088 100644
--- a/libraries/classes/Plugins/Export/ExportLatex.php
+++ b/libraries/classes/Plugins/Export/ExportLatex.php
@@ -79,14 +79,14 @@ class ExportLatex extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
         $leaf = new BoolPropertyItem(
-            "caption",
+            'caption',
             __('Include table caption')
         );
         $generalOptions->addProperty($leaf);
@@ -95,11 +95,11 @@ class ExportLatex extends ExportPlugin
 
         // what to dump (structure/data/both) main group
         $dumpWhat = new OptionsPropertyMainGroup(
-            "dump_what",
+            'dump_what',
             __('Dump table')
         );
         // create primary items and add them to the group
-        $leaf = new RadioPropertyItem("structure_or_data");
+        $leaf = new RadioPropertyItem('structure_or_data');
         $leaf->setValues(
             [
                 'structure'          => __('structure'),
@@ -114,44 +114,44 @@ class ExportLatex extends ExportPlugin
         // structure options main group
         if (! $hide_structure) {
             $structureOptions = new OptionsPropertyMainGroup(
-                "structure",
+                'structure',
                 __('Object creation options')
             );
             $structureOptions->setForce('data');
             // create primary items and add them to the group
             $leaf = new TextPropertyItem(
-                "structure_caption",
+                'structure_caption',
                 __('Table caption:')
             );
             $leaf->setDoc('faq6-27');
             $structureOptions->addProperty($leaf);
             $leaf = new TextPropertyItem(
-                "structure_continued_caption",
+                'structure_continued_caption',
                 __('Table caption (continued):')
             );
             $leaf->setDoc('faq6-27');
             $structureOptions->addProperty($leaf);
             $leaf = new TextPropertyItem(
-                "structure_label",
+                'structure_label',
                 __('Label key:')
             );
             $leaf->setDoc('faq6-27');
             $structureOptions->addProperty($leaf);
             if (! empty($GLOBALS['cfgRelation']['relation'])) {
                 $leaf = new BoolPropertyItem(
-                    "relation",
+                    'relation',
                     __('Display foreign key relationships')
                 );
                 $structureOptions->addProperty($leaf);
             }
             $leaf = new BoolPropertyItem(
-                "comments",
+                'comments',
                 __('Display comments')
             );
             $structureOptions->addProperty($leaf);
             if (! empty($GLOBALS['cfgRelation']['mimework'])) {
                 $leaf = new BoolPropertyItem(
-                    "mime",
+                    'mime',
                     __('Display media types')
                 );
                 $structureOptions->addProperty($leaf);
@@ -162,30 +162,30 @@ class ExportLatex extends ExportPlugin
 
         // data options main group
         $dataOptions = new OptionsPropertyMainGroup(
-            "data",
+            'data',
             __('Data dump options')
         );
         $dataOptions->setForce('structure');
         // create primary items and add them to the group
         $leaf = new BoolPropertyItem(
-            "columns",
+            'columns',
             __('Put columns names in the first row:')
         );
         $dataOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "data_caption",
+            'data_caption',
             __('Table caption:')
         );
         $leaf->setDoc('faq6-27');
         $dataOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "data_continued_caption",
+            'data_continued_caption',
             __('Table caption (continued):')
         );
         $leaf->setDoc('faq6-27');
         $dataOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "data_label",
+            'data_label',
             __('Label key:')
         );
         $leaf->setDoc('faq6-27');
@@ -425,7 +425,7 @@ class ExportLatex extends ExportPlugin
                 if ($i == ($columns_cnt - 1)) {
                     $buffer .= $column_value;
                 } else {
-                    $buffer .= $column_value . " & ";
+                    $buffer .= $column_value . ' & ';
                 }
             }
             $buffer .= ' \\\\ \\hline ' . $crlf;
diff --git a/libraries/classes/Plugins/Export/ExportMediawiki.php b/libraries/classes/Plugins/Export/ExportMediawiki.php
index f2ca9dee62..957645f709 100644
--- a/libraries/classes/Plugins/Export/ExportMediawiki.php
+++ b/libraries/classes/Plugins/Export/ExportMediawiki.php
@@ -54,19 +54,19 @@ class ExportMediawiki extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
         $generalOptions = new OptionsPropertyMainGroup(
-            "general_opts",
+            'general_opts',
             __('Dump table')
         );
 
         // what to dump (structure/data/both)
         $subgroup = new OptionsPropertySubgroup(
-            "dump_table",
-            __("Dump table")
+            'dump_table',
+            __('Dump table')
         );
         $leaf = new RadioPropertyItem('structure_or_data');
         $leaf->setValues(
@@ -81,14 +81,14 @@ class ExportMediawiki extends ExportPlugin
 
         // export table name
         $leaf = new BoolPropertyItem(
-            "caption",
+            'caption',
             __('Export table names')
         );
         $generalOptions->addProperty($leaf);
 
         // export table headers
         $leaf = new BoolPropertyItem(
-            "headers",
+            'headers',
             __('Export table headers')
         );
         $generalOptions->addProperty($leaf);
@@ -208,12 +208,12 @@ class ExportMediawiki extends ExportPlugin
 
                 // Print structure comment
                 $output = $this->_exportComment(
-                    "Table structure for "
+                    'Table structure for '
                     . Util::backquote($table_alias)
                 );
 
                 // Begin the table construction
-                $output .= "{| class=\"wikitable\" style=\"text-align:center;\""
+                $output .= '{| class="wikitable" style="text-align:center;"'
                     . $this->_exportCRLF();
 
                 // Add the table name
@@ -223,8 +223,8 @@ class ExportMediawiki extends ExportPlugin
 
                 // Add the table headers
                 if (isset($GLOBALS['mediawiki_headers'])) {
-                    $output .= "|- style=\"background:#ffdead;\"" . $this->_exportCRLF();
-                    $output .= "! style=\"background:#ffffff\" | "
+                    $output .= '|- style="background:#ffdead;"' . $this->_exportCRLF();
+                    $output .= '! style="background:#ffffff" | '
                     . $this->_exportCRLF();
                     for ($i = 0; $i < $row_cnt; ++$i) {
                         $col_as = $columns[$i]['Field'];
@@ -233,36 +233,36 @@ class ExportMediawiki extends ExportPlugin
                             $col_as
                                 = $aliases[$db]['tables'][$table]['columns'][$col_as];
                         }
-                        $output .= " | " . $col_as . $this->_exportCRLF();
+                        $output .= ' | ' . $col_as . $this->_exportCRLF();
                     }
                 }
 
                 // Add the table structure
-                $output .= "|-" . $this->_exportCRLF();
-                $output .= "! Type" . $this->_exportCRLF();
+                $output .= '|-' . $this->_exportCRLF();
+                $output .= '! Type' . $this->_exportCRLF();
                 for ($i = 0; $i < $row_cnt; ++$i) {
-                    $output .= " | " . $columns[$i]['Type'] . $this->_exportCRLF();
+                    $output .= ' | ' . $columns[$i]['Type'] . $this->_exportCRLF();
                 }
 
-                $output .= "|-" . $this->_exportCRLF();
-                $output .= "! Null" . $this->_exportCRLF();
+                $output .= '|-' . $this->_exportCRLF();
+                $output .= '! Null' . $this->_exportCRLF();
                 for ($i = 0; $i < $row_cnt; ++$i) {
-                    $output .= " | " . $columns[$i]['Null'] . $this->_exportCRLF();
+                    $output .= ' | ' . $columns[$i]['Null'] . $this->_exportCRLF();
                 }
 
-                $output .= "|-" . $this->_exportCRLF();
-                $output .= "! Default" . $this->_exportCRLF();
+                $output .= '|-' . $this->_exportCRLF();
+                $output .= '! Default' . $this->_exportCRLF();
                 for ($i = 0; $i < $row_cnt; ++$i) {
-                    $output .= " | " . $columns[$i]['Default'] . $this->_exportCRLF();
+                    $output .= ' | ' . $columns[$i]['Default'] . $this->_exportCRLF();
                 }
 
-                $output .= "|-" . $this->_exportCRLF();
-                $output .= "! Extra" . $this->_exportCRLF();
+                $output .= '|-' . $this->_exportCRLF();
+                $output .= '! Extra' . $this->_exportCRLF();
                 for ($i = 0; $i < $row_cnt; ++$i) {
-                    $output .= " | " . $columns[$i]['Extra'] . $this->_exportCRLF();
+                    $output .= ' | ' . $columns[$i]['Extra'] . $this->_exportCRLF();
                 }
 
-                $output .= "|}" . str_repeat($this->_exportCRLF(), 2);
+                $output .= '|}' . str_repeat($this->_exportCRLF(), 2);
                 break;
         } // end switch
 
@@ -295,13 +295,13 @@ class ExportMediawiki extends ExportPlugin
 
         // Print data comment
         $output = $this->_exportComment(
-            "Table data for " . Util::backquote($table_alias)
+            'Table data for ' . Util::backquote($table_alias)
         );
 
         // Begin the table construction
         // Use the "wikitable" class for style
         // Use the "sortable"  class for allowing tables to be sorted by column
-        $output .= "{| class=\"wikitable sortable\" style=\"text-align:center;\""
+        $output .= '{| class="wikitable sortable" style="text-align:center;"'
             . $this->_exportCRLF();
 
         // Add the table name
@@ -317,7 +317,7 @@ class ExportMediawiki extends ExportPlugin
             // Add column names as table headers
             if ($column_names !== null) {
                 // Use '|-' for separating rows
-                $output .= "|-" . $this->_exportCRLF();
+                $output .= '|-' . $this->_exportCRLF();
 
                 // Use '!' for separating table headers
                 foreach ($column_names as $column) {
@@ -326,7 +326,7 @@ class ExportMediawiki extends ExportPlugin
                         $column
                             = $aliases[$db]['tables'][$table]['columns'][$column];
                     }
-                    $output .= " ! " . $column . "" . $this->_exportCRLF();
+                    $output .= ' ! ' . $column . '' . $this->_exportCRLF();
                 }
             }
         }
@@ -340,16 +340,16 @@ class ExportMediawiki extends ExportPlugin
         $fields_cnt = $GLOBALS['dbi']->numFields($result);
 
         while ($row = $GLOBALS['dbi']->fetchRow($result)) {
-            $output .= "|-" . $this->_exportCRLF();
+            $output .= '|-' . $this->_exportCRLF();
 
             // Use '|' for separating table columns
             for ($i = 0; $i < $fields_cnt; ++$i) {
-                $output .= " | " . $row[$i] . "" . $this->_exportCRLF();
+                $output .= ' | ' . $row[$i] . '' . $this->_exportCRLF();
             }
         }
 
         // End table construction
-        $output .= "|}" . str_repeat($this->_exportCRLF(), 2);
+        $output .= '|}' . str_repeat($this->_exportCRLF(), 2);
 
         return $this->export->outputHandler($output);
     }
diff --git a/libraries/classes/Plugins/Export/ExportOds.php b/libraries/classes/Plugins/Export/ExportOds.php
index fa6709a691..9f37ba6025 100644
--- a/libraries/classes/Plugins/Export/ExportOds.php
+++ b/libraries/classes/Plugins/Export/ExportOds.php
@@ -58,23 +58,23 @@ class ExportOds extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
         $leaf = new TextPropertyItem(
-            "null",
+            'null',
             __('Replace NULL with:')
         );
         $generalOptions->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "columns",
+            'columns',
             __('Put columns names in the first row')
         );
         $generalOptions->addProperty($leaf);
-        $leaf = new HiddenPropertyItem("structure_or_data");
+        $leaf = new HiddenPropertyItem('structure_or_data');
         $generalOptions->addProperty($leaf);
         // add the main group to the root group
         $exportSpecificOptions->addProperty($generalOptions);
@@ -282,31 +282,31 @@ class ExportOds extends ExportPlugin
                         .= '<table:table-cell office:value-type="string">'
                         . '<text:p></text:p>'
                         . '</table:table-cell>';
-                } elseif ($fields_meta[$j]->type == "date") {
+                } elseif ($fields_meta[$j]->type == 'date') {
                     $GLOBALS['ods_buffer']
                         .= '<table:table-cell office:value-type="date"'
                         . ' office:date-value="'
-                        . date("Y-m-d", strtotime($row[$j]))
+                        . date('Y-m-d', strtotime($row[$j]))
                         . '" table:style-name="DateCell">'
                         . '<text:p>'
                         . htmlspecialchars($row[$j])
                         . '</text:p>'
                         . '</table:table-cell>';
-                } elseif ($fields_meta[$j]->type == "time") {
+                } elseif ($fields_meta[$j]->type == 'time') {
                     $GLOBALS['ods_buffer']
                         .= '<table:table-cell office:value-type="time"'
                         . ' office:time-value="'
-                        . date("\P\TH\Hi\Ms\S", strtotime($row[$j]))
+                        . date('\P\TH\Hi\Ms\S', strtotime($row[$j]))
                         . '" table:style-name="TimeCell">'
                         . '<text:p>'
                         . htmlspecialchars($row[$j])
                         . '</text:p>'
                         . '</table:table-cell>';
-                } elseif ($fields_meta[$j]->type == "datetime") {
+                } elseif ($fields_meta[$j]->type == 'datetime') {
                     $GLOBALS['ods_buffer']
                         .= '<table:table-cell office:value-type="date"'
                         . ' office:date-value="'
-                        . date("Y-m-d\TH:i:s", strtotime($row[$j]))
+                        . date('Y-m-d\TH:i:s', strtotime($row[$j]))
                         . '" table:style-name="DateTimeCell">'
                         . '<text:p>'
                         . htmlspecialchars($row[$j])
diff --git a/libraries/classes/Plugins/Export/ExportOdt.php b/libraries/classes/Plugins/Export/ExportOdt.php
index de63708eae..51e83ee628 100644
--- a/libraries/classes/Plugins/Export/ExportOdt.php
+++ b/libraries/classes/Plugins/Export/ExportOdt.php
@@ -68,16 +68,16 @@ class ExportOdt extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // what to dump (structure/data/both) main group
         $dumpWhat = new OptionsPropertyMainGroup(
-            "general_opts",
+            'general_opts',
             __('Dump table')
         );
         // create primary items and add them to the group
-        $leaf = new RadioPropertyItem("structure_or_data");
+        $leaf = new RadioPropertyItem('structure_or_data');
         $leaf->setValues(
             [
                 'structure'          => __('structure'),
@@ -92,26 +92,26 @@ class ExportOdt extends ExportPlugin
         // structure options main group
         if (! $hide_structure) {
             $structureOptions = new OptionsPropertyMainGroup(
-                "structure",
+                'structure',
                 __('Object creation options')
             );
             $structureOptions->setForce('data');
             // create primary items and add them to the group
             if (! empty($GLOBALS['cfgRelation']['relation'])) {
                 $leaf = new BoolPropertyItem(
-                    "relation",
+                    'relation',
                     __('Display foreign key relationships')
                 );
                 $structureOptions->addProperty($leaf);
             }
             $leaf = new BoolPropertyItem(
-                "comments",
+                'comments',
                 __('Display comments')
             );
             $structureOptions->addProperty($leaf);
             if (! empty($GLOBALS['cfgRelation']['mimework'])) {
                 $leaf = new BoolPropertyItem(
-                    "mime",
+                    'mime',
                     __('Display media types')
                 );
                 $structureOptions->addProperty($leaf);
@@ -122,13 +122,13 @@ class ExportOdt extends ExportPlugin
 
         // data options main group
         $dataOptions = new OptionsPropertyMainGroup(
-            "data",
+            'data',
             __('Data dump options')
         );
         $dataOptions->setForce('structure');
         // create primary items and add them to the group
         $leaf = new BoolPropertyItem(
-            "columns",
+            'columns',
             __('Put columns names in the first row')
         );
         $dataOptions->addProperty($leaf);
diff --git a/libraries/classes/Plugins/Export/ExportPdf.php b/libraries/classes/Plugins/Export/ExportPdf.php
index 7fc800cae1..8552b6a656 100644
--- a/libraries/classes/Plugins/Export/ExportPdf.php
+++ b/libraries/classes/Plugins/Export/ExportPdf.php
@@ -92,14 +92,14 @@ class ExportPdf extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
         $leaf = new TextPropertyItem(
-            "report_title",
+            'report_title',
             __('Report title:')
         );
         $generalOptions->addProperty($leaf);
@@ -108,10 +108,10 @@ class ExportPdf extends ExportPlugin
 
         // what to dump (structure/data/both) main group
         $dumpWhat = new OptionsPropertyMainGroup(
-            "dump_what",
+            'dump_what',
             __('Dump table')
         );
-        $leaf = new RadioPropertyItem("structure_or_data");
+        $leaf = new RadioPropertyItem('structure_or_data');
         $leaf->setValues(
             [
                 'structure'          => __('structure'),
diff --git a/libraries/classes/Plugins/Export/ExportPhparray.php b/libraries/classes/Plugins/Export/ExportPhparray.php
index 2f05fbd3e2..113e0a3ecb 100644
--- a/libraries/classes/Plugins/Export/ExportPhparray.php
+++ b/libraries/classes/Plugins/Export/ExportPhparray.php
@@ -52,13 +52,13 @@ class ExportPhparray extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
-        $leaf = new HiddenPropertyItem("structure_or_data");
+        $leaf = new HiddenPropertyItem('structure_or_data');
         $generalOptions->addProperty($leaf);
         // add the main group to the root group
         $exportSpecificOptions->addProperty($generalOptions);
@@ -239,7 +239,7 @@ class ExportPhparray extends ExportPlugin
 
             for ($i = 0; $i < $columns_cnt; $i++) {
                 $buffer .= var_export($columns[$i], true)
-                    . " => " . var_export($record[$i], true)
+                    . ' => ' . var_export($record[$i], true)
                     . (($i + 1 >= $columns_cnt) ? '' : ',');
             }
 
diff --git a/libraries/classes/Plugins/Export/ExportSql.php b/libraries/classes/Plugins/Export/ExportSql.php
index d50a0a8f4d..4fe2aee404 100644
--- a/libraries/classes/Plugins/Export/ExportSql.php
+++ b/libraries/classes/Plugins/Export/ExportSql.php
@@ -88,14 +88,14 @@ class ExportSql extends ExportPlugin
             // $exportPluginProperties
             // this will be shown as "Format specific options"
             $exportSpecificOptions = new OptionsPropertyRootGroup(
-                "Format Specific Options"
+                'Format Specific Options'
             );
 
             // general options main group
-            $generalOptions = new OptionsPropertyMainGroup("general_opts");
+            $generalOptions = new OptionsPropertyMainGroup('general_opts');
 
             // comments
-            $subgroup = new OptionsPropertySubgroup("include_comments");
+            $subgroup = new OptionsPropertySubgroup('include_comments');
             $leaf = new BoolPropertyItem(
                 'include_comments',
                 __(
@@ -136,7 +136,7 @@ class ExportSql extends ExportPlugin
 
             // enclose in a transaction
             $leaf = new BoolPropertyItem(
-                "use_transaction",
+                'use_transaction',
                 __('Enclose export in a transaction')
             );
             $leaf->setDoc(
@@ -150,7 +150,7 @@ class ExportSql extends ExportPlugin
 
             // disable foreign key checks
             $leaf = new BoolPropertyItem(
-                "disable_fk",
+                'disable_fk',
                 __('Disable foreign key checks')
             );
             $leaf->setDoc(
@@ -164,14 +164,14 @@ class ExportSql extends ExportPlugin
 
             // export views as tables
             $leaf = new BoolPropertyItem(
-                "views_as_tables",
+                'views_as_tables',
                 __('Export views as tables')
             );
             $generalOptions->addProperty($leaf);
 
             // export metadata
             $leaf = new BoolPropertyItem(
-                "metadata",
+                'metadata',
                 __('Export metadata')
             );
             $generalOptions->addProperty($leaf);
@@ -185,7 +185,7 @@ class ExportSql extends ExportPlugin
                 }
 
                 $leaf = new SelectPropertyItem(
-                    "compatibility",
+                    'compatibility',
                     __(
                         'Database system or older MySQL server to maximize output'
                         . ' compatibility with:'
@@ -205,8 +205,8 @@ class ExportSql extends ExportPlugin
 
             // what to dump (structure/data/both)
             $subgroup = new OptionsPropertySubgroup(
-                "dump_table",
-                __("Dump table")
+                'dump_table',
+                __('Dump table')
             );
             $leaf = new RadioPropertyItem('structure_or_data');
             $leaf->setValues(
@@ -225,7 +225,7 @@ class ExportSql extends ExportPlugin
             // structure options main group
             if (! $hide_structure) {
                 $structureOptions = new OptionsPropertyMainGroup(
-                    "structure",
+                    'structure',
                     __('Object creation options')
                 );
                 $structureOptions->setForce('data');
@@ -241,7 +241,7 @@ class ExportSql extends ExportPlugin
                 // server export options
                 if ($plugin_param['export_type'] == 'server') {
                     $leaf = new BoolPropertyItem(
-                        "drop_database",
+                        'drop_database',
                         sprintf(__('Add %s statement'), '<code>DROP DATABASE IF EXISTS</code>')
                     );
                     $subgroup->addProperty($leaf);
@@ -343,7 +343,7 @@ class ExportSql extends ExportPlugin
                 $structureOptions->addProperty($subgroup);
 
                 $leaf = new BoolPropertyItem(
-                    "backquotes",
+                    'backquotes',
                     __(
                         'Enclose table and column names with backquotes '
                         . '<i>(Protects column and table names formed with'
@@ -359,12 +359,12 @@ class ExportSql extends ExportPlugin
 
             // begin Data options
             $dataOptions = new OptionsPropertyMainGroup(
-                "data",
+                'data',
                 __('Data creation options')
             );
             $dataOptions->setForce('structure');
             $leaf = new BoolPropertyItem(
-                "truncate",
+                'truncate',
                 __('Truncate table before insert')
             );
             $dataOptions->addProperty($leaf);
@@ -377,7 +377,7 @@ class ExportSql extends ExportPlugin
             $subgroup->setSubgroupHeader($leaf);
 
             $leaf = new BoolPropertyItem(
-                "delayed",
+                'delayed',
                 __('<code>INSERT DELAYED</code> statements')
             );
             $leaf->setDoc(
@@ -389,7 +389,7 @@ class ExportSql extends ExportPlugin
             $subgroup->addProperty($leaf);
 
             $leaf = new BoolPropertyItem(
-                "ignore",
+                'ignore',
                 __('<code>INSERT IGNORE</code> statements')
             );
             $leaf->setDoc(
@@ -403,7 +403,7 @@ class ExportSql extends ExportPlugin
 
             // Function to use when dumping dat
             $leaf = new SelectPropertyItem(
-                "type",
+                'type',
                 __('Function to use when dumping data:')
             );
             $leaf->setValues(
@@ -423,7 +423,7 @@ class ExportSql extends ExportPlugin
             );
             $subgroup->setSubgroupHeader($leaf);
             $leaf = new RadioPropertyItem(
-                "insert_syntax",
+                'insert_syntax',
                 __('<code>INSERT IGNORE</code> statements')
             );
             $leaf->setValues(
@@ -454,14 +454,14 @@ class ExportSql extends ExportPlugin
 
             // Max length of query
             $leaf = new NumberPropertyItem(
-                "max_query_size",
+                'max_query_size',
                 __('Maximal length of created query')
             );
             $dataOptions->addProperty($leaf);
 
             // Dump binary columns in hexadecimal
             $leaf = new BoolPropertyItem(
-                "hex_for_binary",
+                'hex_for_binary',
                 __(
                     'Dump binary columns in hexadecimal notation'
                     . ' <i>(for example, "abc" becomes 0x616263)</i>'
@@ -471,7 +471,7 @@ class ExportSql extends ExportPlugin
 
             // Dump time in UTC
             $leaf = new BoolPropertyItem(
-                "utc_time",
+                'utc_time',
                 __(
                     'Dump TIMESTAMP columns in UTC <i>(enables TIMESTAMP columns'
                     . ' to be dumped and reloaded between servers in different'
@@ -972,14 +972,14 @@ class ExportSql extends ExportPlugin
         $delimiter = '$$';
 
         $event_names = $GLOBALS['dbi']->fetchResult(
-            "SELECT EVENT_NAME FROM information_schema.EVENTS WHERE"
+            'SELECT EVENT_NAME FROM information_schema.EVENTS WHERE'
             . " EVENT_SCHEMA= '" . $GLOBALS['dbi']->escapeString($db)
             . "';"
         );
 
         if ($event_names) {
             $text .= $crlf
-                . "DELIMITER " . $delimiter . $crlf;
+                . 'DELIMITER ' . $delimiter . $crlf;
 
             $text .= $this->_exportComment()
                 . $this->_exportComment(__('Events'))
@@ -987,7 +987,7 @@ class ExportSql extends ExportPlugin
 
             foreach ($event_names as $event_name) {
                 if (! empty($GLOBALS['sql_drop_table'])) {
-                    $text .= "DROP EVENT "
+                    $text .= 'DROP EVENT '
                         . Util::backquote($event_name)
                         . $delimiter . $crlf;
                 }
@@ -995,7 +995,7 @@ class ExportSql extends ExportPlugin
                     . $delimiter . $crlf . $crlf;
             }
 
-            $text .= "DELIMITER ;" . $crlf;
+            $text .= 'DELIMITER ;' . $crlf;
         }
 
         if (! empty($text)) {
@@ -1120,10 +1120,10 @@ class ExportSql extends ExportPlugin
             if (in_array($type, $metadataTypes) && isset($cfgRelation[$type])) {
                 // special case, designer pages and their coordinates
                 if ($type == 'pdf_pages') {
-                    $sql_query = "SELECT `page_nr`, `page_descr` FROM "
+                    $sql_query = 'SELECT `page_nr`, `page_descr` FROM '
                         . Util::backquote($cfgRelation['db'])
-                        . "." . Util::backquote($cfgRelation[$type])
-                        . " WHERE " . Util::backquote($dbNameColumn)
+                        . '.' . Util::backquote($cfgRelation[$type])
+                        . ' WHERE ' . Util::backquote($dbNameColumn)
                         . " = '" . $GLOBALS['dbi']->escapeString($db) . "'";
 
                     $result = $GLOBALS['dbi']->fetchResult(
@@ -1134,12 +1134,12 @@ class ExportSql extends ExportPlugin
 
                     foreach ($result as $page => $name) {
                         // insert row for pdf_page
-                        $sql_query_row = "SELECT `db_name`, `page_descr` FROM "
+                        $sql_query_row = 'SELECT `db_name`, `page_descr` FROM '
                             . Util::backquote($cfgRelation['db'])
-                            . "." . Util::backquote(
+                            . '.' . Util::backquote(
                                 $cfgRelation[$type]
                             )
-                            . " WHERE " . Util::backquote(
+                            . ' WHERE ' . Util::backquote(
                                 $dbNameColumn
                             )
                             . " = '" . $GLOBALS['dbi']->escapeString($db) . "'"
@@ -1158,16 +1158,16 @@ class ExportSql extends ExportPlugin
                         }
 
                         $lastPage = $GLOBALS['crlf']
-                            . "SET @LAST_PAGE = LAST_INSERT_ID();"
+                            . 'SET @LAST_PAGE = LAST_INSERT_ID();'
                             . $GLOBALS['crlf'];
                         if (! $this->export->outputHandler($lastPage)) {
                             return false;
                         }
 
-                        $sql_query_coords = "SELECT `db_name`, `table_name`, "
+                        $sql_query_coords = 'SELECT `db_name`, `table_name`, '
                             . "'@LAST_PAGE' AS `pdf_page_number`, `x`, `y` FROM "
                             . Util::backquote($cfgRelation['db'])
-                            . "." . Util::backquote(
+                            . '.' . Util::backquote(
                                 $cfgRelation['table_coords']
                             )
                             . " WHERE `pdf_page_number` = '" . $page . "'";
@@ -1193,21 +1193,21 @@ class ExportSql extends ExportPlugin
 
                 // remove auto_incrementing id field for some tables
                 if ($type == 'bookmark') {
-                    $sql_query = "SELECT `dbase`, `user`, `label`, `query` FROM ";
+                    $sql_query = 'SELECT `dbase`, `user`, `label`, `query` FROM ';
                 } elseif ($type == 'column_info') {
-                    $sql_query = "SELECT `db_name`, `table_name`, `column_name`,"
-                        . " `comment`, `mimetype`, `transformation`,"
-                        . " `transformation_options`, `input_transformation`,"
-                        . " `input_transformation_options` FROM";
+                    $sql_query = 'SELECT `db_name`, `table_name`, `column_name`,'
+                        . ' `comment`, `mimetype`, `transformation`,'
+                        . ' `transformation_options`, `input_transformation`,'
+                        . ' `input_transformation_options` FROM';
                 } elseif ($type == 'savedsearches') {
-                    $sql_query = "SELECT `username`, `db_name`, `search_name`,"
-                        . " `search_data` FROM";
+                    $sql_query = 'SELECT `username`, `db_name`, `search_name`,'
+                        . ' `search_data` FROM';
                 } else {
-                    $sql_query = "SELECT * FROM ";
+                    $sql_query = 'SELECT * FROM ';
                 }
                 $sql_query .= Util::backquote($cfgRelation['db'])
                     . '.' . Util::backquote($cfgRelation[$type])
-                    . " WHERE " . Util::backquote($dbNameColumn)
+                    . ' WHERE ' . Util::backquote($dbNameColumn)
                     . " = '" . $GLOBALS['dbi']->escapeString($db) . "'";
                 if (isset($table)) {
                     $sql_query .= " AND `table_name` = '"
@@ -1298,11 +1298,11 @@ class ExportSql extends ExportPlugin
         $db_alias = $db;
         $view_alias = $view;
         $this->initAlias($aliases, $db_alias, $view_alias);
-        $create_query = "CREATE TABLE";
+        $create_query = 'CREATE TABLE';
         if (isset($GLOBALS['sql_if_not_exists'])) {
-            $create_query .= " IF NOT EXISTS ";
+            $create_query .= ' IF NOT EXISTS ';
         }
-        $create_query .= Util::backquote($view_alias) . "(" . $crlf;
+        $create_query .= Util::backquote($view_alias) . '(' . $crlf;
 
         $columns = $GLOBALS['dbi']->getColumns($db, $view, null, true);
 
@@ -1317,24 +1317,24 @@ class ExportSql extends ExportPlugin
             );
 
             if (! $firstCol) {
-                $create_query .= "," . $crlf;
+                $create_query .= ',' . $crlf;
             }
-            $create_query .= "    " . Util::backquote($col_alias);
-            $create_query .= " " . $column['Type'];
+            $create_query .= '    ' . Util::backquote($col_alias);
+            $create_query .= ' ' . $column['Type'];
             if ($extracted_columnspec['can_contain_collation']
                 && ! empty($column['Collation'])
             ) {
-                $create_query .= " COLLATE " . $column['Collation'];
+                $create_query .= ' COLLATE ' . $column['Collation'];
             }
             if ($column['Null'] == 'NO') {
-                $create_query .= " NOT NULL";
+                $create_query .= ' NOT NULL';
             }
             if (isset($column['Default'])) {
                 $create_query .= " DEFAULT '"
                     . $GLOBALS['dbi']->escapeString($column['Default']) . "'";
             } else {
                 if ($column['Null'] == 'YES') {
-                    $create_query .= " DEFAULT NULL";
+                    $create_query .= ' DEFAULT NULL';
                 }
             }
             if (! empty($column['Comment'])) {
@@ -1343,7 +1343,7 @@ class ExportSql extends ExportPlugin
             }
             $firstCol = false;
         }
-        $create_query .= $crlf . ")" . ($add_semicolon ? ';' : '') . $crlf;
+        $create_query .= $crlf . ')' . ($add_semicolon ? ';' : '') . $crlf;
 
         if (isset($GLOBALS['sql_compatibility'])) {
             $compat = $GLOBALS['sql_compatibility'];
@@ -1516,7 +1516,7 @@ class ExportSql extends ExportPlugin
         // an error can happen, for example the table is crashed
         $tmp_error = $GLOBALS['dbi']->getError();
         if ($tmp_error) {
-            $message = sprintf(__('Error reading structure for table %s:'), "$db.$table");
+            $message = sprintf(__('Error reading structure for table %s:'), $db . '.' . $table);
             $message .= ' ' . $tmp_error;
             if (! defined('TESTSUITE')) {
                 trigger_error($message, E_USER_ERROR);
@@ -2250,7 +2250,7 @@ class ExportSql extends ExportPlugin
         // a possible error: the table has crashed
         $tmp_error = $GLOBALS['dbi']->getError();
         if ($tmp_error) {
-            $message = sprintf(__('Error reading data for table %s:'), "$db.$table");
+            $message = sprintf(__('Error reading data for table %s:'), $db . '.' . $table);
             $message .= ' ' . $tmp_error;
             if (! defined('TESTSUITE')) {
                 trigger_error($message, E_USER_ERROR);
@@ -2333,7 +2333,7 @@ class ExportSql extends ExportPlugin
                         $table_alias,
                         $compat,
                         $sql_backquotes
-                    ) . ";";
+                    ) . ';';
                 $truncatehead = $this->_possibleCRLF()
                     . $this->_exportComment()
                     . $this->_exportComment(
@@ -2590,7 +2590,7 @@ class ExportSql extends ExportPlugin
         // 6. DOUBLE field doesn't exists, we will use FLOAT instead
 
         $create_query = preg_replace(
-            "/^CREATE TABLE IF NOT EXISTS/",
+            '/^CREATE TABLE IF NOT EXISTS/',
             'CREATE TABLE',
             $create_query
         );
diff --git a/libraries/classes/Plugins/Export/ExportTexytext.php b/libraries/classes/Plugins/Export/ExportTexytext.php
index 7587e1bfba..465ca6117f 100644
--- a/libraries/classes/Plugins/Export/ExportTexytext.php
+++ b/libraries/classes/Plugins/Export/ExportTexytext.php
@@ -56,16 +56,16 @@ class ExportTexytext extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // what to dump (structure/data/both) main group
         $dumpWhat = new OptionsPropertyMainGroup(
-            "general_opts",
+            'general_opts',
             __('Dump table')
         );
         // create primary items and add them to the group
-        $leaf = new RadioPropertyItem("structure_or_data");
+        $leaf = new RadioPropertyItem('structure_or_data');
         $leaf->setValues(
             [
                 'structure'          => __('structure'),
@@ -79,13 +79,13 @@ class ExportTexytext extends ExportPlugin
 
         // data options main group
         $dataOptions = new OptionsPropertyMainGroup(
-            "data",
+            'data',
             __('Data dump options')
         );
         $dataOptions->setForce('structure');
         // create primary items and add them to the group
         $leaf = new BoolPropertyItem(
-            "columns",
+            'columns',
             __('Put columns names in the first row')
         );
         $dataOptions->addProperty($leaf);
diff --git a/libraries/classes/Plugins/Export/ExportXml.php b/libraries/classes/Plugins/Export/ExportXml.php
index fb016161d9..6206ef6353 100644
--- a/libraries/classes/Plugins/Export/ExportXml.php
+++ b/libraries/classes/Plugins/Export/ExportXml.php
@@ -87,51 +87,51 @@ class ExportXml extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
-        $leaf = new HiddenPropertyItem("structure_or_data");
+        $leaf = new HiddenPropertyItem('structure_or_data');
         $generalOptions->addProperty($leaf);
         // add the main group to the root group
         $exportSpecificOptions->addProperty($generalOptions);
 
         // export structure main group
         $structure = new OptionsPropertyMainGroup(
-            "structure",
+            'structure',
             __('Object creation options (all are recommended)')
         );
 
         // create primary items and add them to the group
         $leaf = new BoolPropertyItem(
-            "export_events",
+            'export_events',
             __('Events')
         );
         $structure->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "export_functions",
+            'export_functions',
             __('Functions')
         );
         $structure->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "export_procedures",
+            'export_procedures',
             __('Procedures')
         );
         $structure->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "export_tables",
+            'export_tables',
             __('Tables')
         );
         $structure->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "export_triggers",
+            'export_triggers',
             __('Triggers')
         );
         $structure->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "export_views",
+            'export_views',
             __('Views')
         );
         $structure->addProperty($leaf);
@@ -139,12 +139,12 @@ class ExportXml extends ExportPlugin
 
         // data main group
         $data = new OptionsPropertyMainGroup(
-            "data",
+            'data',
             __('Data dump options')
         );
         // create primary items and add them to the group
         $leaf = new BoolPropertyItem(
-            "export_contents",
+            'export_contents',
             __('Export contents')
         );
         $data->addProperty($leaf);
@@ -200,7 +200,7 @@ class ExportXml extends ExportPlugin
                 $sql = htmlspecialchars(rtrim($sql));
                 $sql = str_replace("\n", "\n                ", $sql);
 
-                $head .= "                " . $sql . $crlf;
+                $head .= '                ' . $sql . $crlf;
                 $head .= '            </pma:' . $type . '>' . $crlf;
             }
         }
@@ -311,7 +311,7 @@ class ExportXml extends ExportPlugin
                 $head .= '            <pma:' . $type . ' name="' . htmlspecialchars($table) . '">'
                     . $crlf;
 
-                $tbl = "                " . htmlspecialchars($tbl);
+                $tbl = '                ' . htmlspecialchars($tbl);
                 $tbl = str_replace("\n", "\n                ", $tbl);
 
                 $head .= $tbl . ';' . $crlf;
@@ -330,7 +330,7 @@ class ExportXml extends ExportPlugin
 
                             // Do some formatting
                             $code = mb_substr(rtrim($code), 0, -3);
-                            $code = "                " . htmlspecialchars($code);
+                            $code = '                ' . htmlspecialchars($code);
                             $code = str_replace("\n", "\n                ", $code);
 
                             $head .= $code . $crlf;
@@ -359,7 +359,7 @@ class ExportXml extends ExportPlugin
             ) {
                 // Export events
                 $events = $GLOBALS['dbi']->fetchResult(
-                    "SELECT EVENT_NAME FROM information_schema.EVENTS "
+                    'SELECT EVENT_NAME FROM information_schema.EVENTS '
                     . "WHERE EVENT_SCHEMA='" . $GLOBALS['dbi']->escapeString($db)
                     . "'"
                 );
diff --git a/libraries/classes/Plugins/Export/ExportYaml.php b/libraries/classes/Plugins/Export/ExportYaml.php
index 23d661c2e8..c008efb812 100644
--- a/libraries/classes/Plugins/Export/ExportYaml.php
+++ b/libraries/classes/Plugins/Export/ExportYaml.php
@@ -52,13 +52,13 @@ class ExportYaml extends ExportPlugin
         // $exportPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
-        $leaf = new HiddenPropertyItem("structure_or_data");
+        $leaf = new HiddenPropertyItem('structure_or_data');
         $generalOptions->addProperty($leaf);
         // add the main group to the root group
         $exportSpecificOptions->addProperty($generalOptions);
diff --git a/libraries/classes/Plugins/Export/Helpers/TableProperty.php b/libraries/classes/Plugins/Export/Helpers/TableProperty.php
index ebdaf2c521..2a8415ec0e 100644
--- a/libraries/classes/Plugins/Export/Helpers/TableProperty.php
+++ b/libraries/classes/Plugins/Export/Helpers/TableProperty.php
@@ -83,7 +83,7 @@ class TableProperty
      */
     public function getPureType()
     {
-        $pos = mb_strpos($this->type, "(");
+        $pos = mb_strpos($this->type, '(');
         if ($pos > 0) {
             return mb_substr($this->type, 0, $pos);
         }
@@ -97,7 +97,7 @@ class TableProperty
      */
     public function isNotNull()
     {
-        return $this->nullable === "NO" ? "true" : "false";
+        return $this->nullable === 'NO' ? 'true' : 'false';
     }
 
     /**
@@ -107,7 +107,7 @@ class TableProperty
      */
     public function isUnique(): string
     {
-        return ($this->key === "PRI" || $this->key === "UNI") ? "true" : "false";
+        return ($this->key === 'PRI' || $this->key === 'UNI') ? 'true' : 'false';
     }
 
     /**
@@ -117,31 +117,31 @@ class TableProperty
      */
     public function getDotNetPrimitiveType()
     {
-        if (mb_strpos($this->type, "int") === 0) {
-            return "int";
+        if (mb_strpos($this->type, 'int') === 0) {
+            return 'int';
         }
-        if (mb_strpos($this->type, "longtext") === 0) {
-            return "string";
+        if (mb_strpos($this->type, 'longtext') === 0) {
+            return 'string';
         }
-        if (mb_strpos($this->type, "long") === 0) {
-            return "long";
+        if (mb_strpos($this->type, 'long') === 0) {
+            return 'long';
         }
-        if (mb_strpos($this->type, "char") === 0) {
-            return "string";
+        if (mb_strpos($this->type, 'char') === 0) {
+            return 'string';
         }
-        if (mb_strpos($this->type, "varchar") === 0) {
-            return "string";
+        if (mb_strpos($this->type, 'varchar') === 0) {
+            return 'string';
         }
-        if (mb_strpos($this->type, "text") === 0) {
-            return "string";
+        if (mb_strpos($this->type, 'text') === 0) {
+            return 'string';
         }
-        if (mb_strpos($this->type, "tinyint") === 0) {
-            return "bool";
+        if (mb_strpos($this->type, 'tinyint') === 0) {
+            return 'bool';
         }
-        if (mb_strpos($this->type, "datetime") === 0) {
-            return "DateTime";
+        if (mb_strpos($this->type, 'datetime') === 0) {
+            return 'DateTime';
         }
-        return "unknown";
+        return 'unknown';
     }
 
     /**
@@ -151,31 +151,31 @@ class TableProperty
      */
     public function getDotNetObjectType()
     {
-        if (mb_strpos($this->type, "int") === 0) {
-            return "Int32";
+        if (mb_strpos($this->type, 'int') === 0) {
+            return 'Int32';
         }
-        if (mb_strpos($this->type, "longtext") === 0) {
-            return "String";
+        if (mb_strpos($this->type, 'longtext') === 0) {
+            return 'String';
         }
-        if (mb_strpos($this->type, "long") === 0) {
-            return "Long";
+        if (mb_strpos($this->type, 'long') === 0) {
+            return 'Long';
         }
-        if (mb_strpos($this->type, "char") === 0) {
-            return "String";
+        if (mb_strpos($this->type, 'char') === 0) {
+            return 'String';
         }
-        if (mb_strpos($this->type, "varchar") === 0) {
-            return "String";
+        if (mb_strpos($this->type, 'varchar') === 0) {
+            return 'String';
         }
-        if (mb_strpos($this->type, "text") === 0) {
-            return "String";
+        if (mb_strpos($this->type, 'text') === 0) {
+            return 'String';
         }
-        if (mb_strpos($this->type, "tinyint") === 0) {
-            return "Boolean";
+        if (mb_strpos($this->type, 'tinyint') === 0) {
+            return 'Boolean';
         }
-        if (mb_strpos($this->type, "datetime") === 0) {
-            return "DateTime";
+        if (mb_strpos($this->type, 'datetime') === 0) {
+            return 'DateTime';
         }
-        return "Unknown";
+        return 'Unknown';
     }
 
     /**
@@ -186,11 +186,11 @@ class TableProperty
     public function getIndexName()
     {
         if (strlen($this->key) > 0) {
-            return "index=\""
+            return 'index="'
                 . htmlspecialchars($this->name, ENT_COMPAT, 'UTF-8')
-                . "\"";
+                . '"';
         }
-        return "";
+        return '';
     }
 
     /**
@@ -200,7 +200,7 @@ class TableProperty
      */
     public function isPK(): bool
     {
-        return $this->key === "PRI";
+        return $this->key === 'PRI';
     }
 
     /**
diff --git a/libraries/classes/Plugins/Import/AbstractImportCsv.php b/libraries/classes/Plugins/Import/AbstractImportCsv.php
index 146e75c4df..c2d42963b4 100644
--- a/libraries/classes/Plugins/Import/AbstractImportCsv.php
+++ b/libraries/classes/Plugins/Import/AbstractImportCsv.php
@@ -39,15 +39,15 @@ abstract class AbstractImportCsv extends ImportPlugin
         // $importPluginProperties
         // this will be shown as "Format specific options"
         $importSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
 
         // create common items and add them to the group
         $leaf = new BoolPropertyItem(
-            "replace",
+            'replace',
             __(
                 'Update data when duplicate keys found on import (add ON DUPLICATE '
                 . 'KEY UPDATE)'
@@ -55,27 +55,27 @@ abstract class AbstractImportCsv extends ImportPlugin
         );
         $generalOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "terminated",
+            'terminated',
             __('Columns separated with:')
         );
         $leaf->setSize(2);
         $generalOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "enclosed",
+            'enclosed',
             __('Columns enclosed with:')
         );
         $leaf->setSize(2);
         $leaf->setLen(2);
         $generalOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "escaped",
+            'escaped',
             __('Columns escaped with:')
         );
         $leaf->setSize(2);
         $leaf->setLen(2);
         $generalOptions->addProperty($leaf);
         $leaf = new TextPropertyItem(
-            "new_line",
+            'new_line',
             __('Lines terminated with:')
         );
         $leaf->setSize(2);
diff --git a/libraries/classes/Plugins/Import/ImportCsv.php b/libraries/classes/Plugins/Import/ImportCsv.php
index df767ed0a8..13beb88b42 100644
--- a/libraries/classes/Plugins/Import/ImportCsv.php
+++ b/libraries/classes/Plugins/Import/ImportCsv.php
@@ -62,7 +62,7 @@ class ImportCsv extends AbstractImportCsv
 
         if ($GLOBALS['plugin_param'] !== 'table') {
             $leaf = new TextPropertyItem(
-                "new_tbl_name",
+                'new_tbl_name',
                 __(
                     'Name of the new table (optional):'
                 )
@@ -71,7 +71,7 @@ class ImportCsv extends AbstractImportCsv
 
             if ($GLOBALS['plugin_param'] === 'server') {
                 $leaf = new TextPropertyItem(
-                    "new_db_name",
+                    'new_db_name',
                     __(
                         'Name of the new database (optional):'
                     )
@@ -80,7 +80,7 @@ class ImportCsv extends AbstractImportCsv
             }
 
             $leaf = new NumberPropertyItem(
-                "partial_import",
+                'partial_import',
                 __(
                     'Import these many number of rows (optional):'
                 )
@@ -88,7 +88,7 @@ class ImportCsv extends AbstractImportCsv
             $generalOptions->addProperty($leaf);
 
             $leaf = new BoolPropertyItem(
-                "col_names",
+                'col_names',
                 __(
                     'The first line of the file contains the table column names'
                     . ' <i>(if this is unchecked, the first line will become part'
@@ -98,7 +98,7 @@ class ImportCsv extends AbstractImportCsv
             $generalOptions->addProperty($leaf);
         } else {
             $leaf = new NumberPropertyItem(
-                "partial_import",
+                'partial_import',
                 __(
                     'Import these many number of rows (optional):'
                 )
@@ -114,14 +114,14 @@ class ImportCsv extends AbstractImportCsv
                 )
             );
             $leaf = new TextPropertyItem(
-                "columns",
+                'columns',
                 __('Column names:') . ' ' . Generator::showHint($hint)
             );
             $generalOptions->addProperty($leaf);
         }
 
         $leaf = new BoolPropertyItem(
-            "ignore",
+            'ignore',
             __('Do not abort on INSERT error')
         );
         $generalOptions->addProperty($leaf);
@@ -142,9 +142,9 @@ class ImportCsv extends AbstractImportCsv
         // but we use directly from $_POST
         global $error, $timeout_passed, $finished, $message;
 
-        $import_file_name = basename($import_file_name, ".csv");
+        $import_file_name = basename($import_file_name, '.csv');
         $import_file_name = mb_strtolower($import_file_name);
-        $import_file_name = preg_replace("/[^a-zA-Z0-9_]/", "_", $import_file_name);
+        $import_file_name = preg_replace('/[^a-zA-Z0-9_]/', '_', $import_file_name);
 
         $replacements = [
             '\\n' => "\n",
@@ -611,13 +611,13 @@ class ImportCsv extends AbstractImportCsv
                         }
                         $sql .= ')';
                         if (isset($_POST['csv_replace'])) {
-                            $sql .= " ON DUPLICATE KEY UPDATE ";
+                            $sql .= ' ON DUPLICATE KEY UPDATE ';
                             foreach ($fields as $field) {
                                 $fieldName = Util::backquote(
                                     $field['Field']
                                 );
-                                $sql .= $fieldName . " = VALUES(" . $fieldName
-                                    . "), ";
+                                $sql .= $fieldName . ' = VALUES(' . $fieldName
+                                    . '), ';
                             }
                             $sql = rtrim($sql, ', ');
                         }
@@ -690,14 +690,14 @@ class ImportCsv extends AbstractImportCsv
                     $tbl_name = $import_file_name;
                 } else {
                     // check to see if {filename} as table exist
-                    $name_array = preg_grep("/{$import_file_name}/isU", $result);
+                    $name_array = preg_grep('/' . $import_file_name . '/isU', $result);
                     // if no use filename as table name
                     if (count($name_array) === 0) {
                         $tbl_name = $import_file_name;
                     } else {
                         // check if {filename}_ as table exist
-                        $name_array = preg_grep("/{$import_file_name}_/isU", $result);
-                        $tbl_name = $import_file_name . "_" . (count($name_array) + 1);
+                        $name_array = preg_grep('/' . $import_file_name . '_/isU', $result);
+                        $tbl_name = $import_file_name . '_' . (count($name_array) + 1);
                     }
                 }
             } else {
diff --git a/libraries/classes/Plugins/Import/ImportLdi.php b/libraries/classes/Plugins/Import/ImportLdi.php
index 3947d85b1e..ff7a5b10a9 100644
--- a/libraries/classes/Plugins/Import/ImportLdi.php
+++ b/libraries/classes/Plugins/Import/ImportLdi.php
@@ -69,19 +69,19 @@ class ImportLdi extends AbstractImportCsv
         $this->properties->setExtension('ldi');
 
         $leaf = new TextPropertyItem(
-            "columns",
+            'columns',
             __('Column names: ')
         );
         $generalOptions->addProperty($leaf);
 
         $leaf = new BoolPropertyItem(
-            "ignore",
+            'ignore',
             __('Do not abort on INSERT error')
         );
         $generalOptions->addProperty($leaf);
 
         $leaf = new BoolPropertyItem(
-            "local_option",
+            'local_option',
             __('Use LOCAL keyword')
         );
         $generalOptions->addProperty($leaf);
diff --git a/libraries/classes/Plugins/Import/ImportMediawiki.php b/libraries/classes/Plugins/Import/ImportMediawiki.php
index fb7371b10f..8b07a077cd 100644
--- a/libraries/classes/Plugins/Import/ImportMediawiki.php
+++ b/libraries/classes/Plugins/Import/ImportMediawiki.php
@@ -92,7 +92,7 @@ class ImportMediawiki extends ImportPlugin
         $mediawiki_new_line = "\n";
 
         // Initialize the name of the current table
-        $cur_table_name = "";
+        $cur_table_name = '';
 
         $cur_temp_table_headers = [];
         $cur_temp_table = [];
@@ -145,12 +145,12 @@ class ImportMediawiki extends ImportPlugin
                 $matches = [];
 
                 // Check beginning of comment
-                if (! strcmp(mb_substr($cur_buffer_line, 0, 4), "<!--")) {
+                if (! strcmp(mb_substr($cur_buffer_line, 0, 4), '<!--')) {
                     $inside_comment = true;
                     continue;
                 } elseif ($inside_comment) {
                     // Check end of comment
-                    if (! strcmp(mb_substr($cur_buffer_line, 0, 4), "-->")
+                    if (! strcmp(mb_substr($cur_buffer_line, 0, 4), '-->')
                     ) {
                         // Only data comments are closed. The structure comments
                         // will be closed when a data comment begins (in order to
@@ -167,7 +167,7 @@ class ImportMediawiki extends ImportPlugin
                         // Check table name
                         $match_table_name = [];
                         if (preg_match(
-                            "/^Table data for `(.*)`$/",
+                            '/^Table data for `(.*)`$/',
                             $cur_buffer_line,
                             $match_table_name
                         )
@@ -180,7 +180,7 @@ class ImportMediawiki extends ImportPlugin
                                     $inside_structure_comment
                                 );
                         } elseif (preg_match(
-                            "/^Table structure for `(.*)`$/",
+                            '/^Table structure for `(.*)`$/',
                             $cur_buffer_line,
                             $match_table_name
                         )
@@ -242,7 +242,7 @@ class ImportMediawiki extends ImportPlugin
                         $this->_importDataOneTable($current_table, $sql_data);
 
                         // Reset table name
-                        $cur_table_name = "";
+                        $cur_table_name = '';
                     }
                     // What's after the row tag is now only attributes
                 } elseif (($first_character === '|') || ($first_character === '!')) {
@@ -266,8 +266,8 @@ class ImportMediawiki extends ImportPlugin
                         // Delete the beginning of the column, if there is one
                         $cell = trim($cell);
                         $col_start_chars = [
-                            "|",
-                            "!",
+                            '|',
+                            '!',
                         ];
                         foreach ($col_start_chars as $col_start_char) {
                             $cell = $this->_getCellContent($cell, $col_start_char);
@@ -420,7 +420,7 @@ class ImportMediawiki extends ImportPlugin
     private function _delimiterReplace($replace, $subject)
     {
         // String that will be returned
-        $cleaned = "";
+        $cleaned = '';
         // Possible states of current character
         $inside_tag = false;
         $inside_attribute = false;
@@ -458,7 +458,7 @@ class ImportMediawiki extends ImportPlugin
                 // not '|', but the previous one was, it means that the single '|'
                 // was not appended, so we append it now
                 if ($partial_separator && $inside_attribute) {
-                    $cleaned .= "|";
+                    $cleaned .= '|';
                 }
                 // If the char is different from "|", no separator can be formed
                 $partial_separator = false;
@@ -504,7 +504,7 @@ class ImportMediawiki extends ImportPlugin
      */
     private function _explodeMarkup($text)
     {
-        $separator = "||";
+        $separator = '||';
         $placeholder = "\x00";
 
         // Remove placeholder instances
diff --git a/libraries/classes/Plugins/Import/ImportOds.php b/libraries/classes/Plugins/Import/ImportOds.php
index 4d5810bca9..feac58eae2 100644
--- a/libraries/classes/Plugins/Import/ImportOds.php
+++ b/libraries/classes/Plugins/Import/ImportOds.php
@@ -54,14 +54,14 @@ class ImportOds extends ImportPlugin
         // $importPluginProperties
         // this will be shown as "Format specific options"
         $importSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // general options main group
-        $generalOptions = new OptionsPropertyMainGroup("general_opts");
+        $generalOptions = new OptionsPropertyMainGroup('general_opts');
         // create primary items and add them to the group
         $leaf = new BoolPropertyItem(
-            "col_names",
+            'col_names',
             __(
                 'The first line of the file contains the table column names'
                 . ' <i>(if this is unchecked, the first line will become part'
@@ -70,19 +70,19 @@ class ImportOds extends ImportPlugin
         );
         $generalOptions->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "empty_rows",
+            'empty_rows',
             __('Do not import empty rows')
         );
         $generalOptions->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "recognize_percentages",
+            'recognize_percentages',
             __(
                 'Import percentages as proper decimals <i>(ex. 12.00% to .12)</i>'
             )
         );
         $generalOptions->addProperty($leaf);
         $leaf = new BoolPropertyItem(
-            "recognize_currency",
+            'recognize_currency',
             __('Import currencies <i>(ex. $5.00 to 5.00)</i>')
         );
         $generalOptions->addProperty($leaf);
@@ -108,7 +108,7 @@ class ImportOds extends ImportPlugin
 
         $i = 0;
         $len = 0;
-        $buffer = "";
+        $buffer = '';
 
         /**
          * Read in the file via Import::getNextChunk so that
@@ -141,7 +141,7 @@ class ImportOds extends ImportPlugin
          * result in increased performance without the need to
          * alter the code in any way. It's basically a freebee.
          */
-        $xml = @simplexml_load_string($buffer, "SimpleXMLElement", LIBXML_COMPACT);
+        $xml = @simplexml_load_string($buffer, 'SimpleXMLElement', LIBXML_COMPACT);
 
         unset($buffer);
 
diff --git a/libraries/classes/Plugins/Import/ImportShp.php b/libraries/classes/Plugins/Import/ImportShp.php
index 0c1c3937d7..f448baa306 100644
--- a/libraries/classes/Plugins/Import/ImportShp.php
+++ b/libraries/classes/Plugins/Import/ImportShp.php
@@ -159,7 +159,7 @@ class ImportShp extends ImportPlugin
 
         // Load data
         $shp->loadFromFile('');
-        if ($shp->lastError != "") {
+        if ($shp->lastError != '') {
             $error = true;
             $message = Message::error(
                 __('There was an error importing the ESRI shape file: "%s".')
diff --git a/libraries/classes/Plugins/Import/ImportSql.php b/libraries/classes/Plugins/Import/ImportSql.php
index 2e9e9d5d35..a6663e2b2b 100644
--- a/libraries/classes/Plugins/Import/ImportSql.php
+++ b/libraries/classes/Plugins/Import/ImportSql.php
@@ -60,14 +60,14 @@ class ImportSql extends ImportPlugin
             // $importPluginProperties
             // this will be shown as "Format specific options"
             $importSpecificOptions = new OptionsPropertyRootGroup(
-                "Format Specific Options"
+                'Format Specific Options'
             );
 
             // general options main group
-            $generalOptions = new OptionsPropertyMainGroup("general_opts");
+            $generalOptions = new OptionsPropertyMainGroup('general_opts');
             // create primary items and add them to the group
             $leaf = new SelectPropertyItem(
-                "compatibility",
+                'compatibility',
                 __('SQL compatibility mode:')
             );
             $leaf->setValues($values);
@@ -79,7 +79,7 @@ class ImportSql extends ImportPlugin
             );
             $generalOptions->addProperty($leaf);
             $leaf = new BoolPropertyItem(
-                "no_auto_value_on_zero",
+                'no_auto_value_on_zero',
                 __('Do not use <code>AUTO_INCREMENT</code> for zero values')
             );
             $leaf->setDoc(
diff --git a/libraries/classes/Plugins/Import/ImportXml.php b/libraries/classes/Plugins/Import/ImportXml.php
index ade1129e5f..658c77ff19 100644
--- a/libraries/classes/Plugins/Import/ImportXml.php
+++ b/libraries/classes/Plugins/Import/ImportXml.php
@@ -65,7 +65,7 @@ class ImportXml extends ImportPlugin
 
         $i = 0;
         $len = 0;
-        $buffer = "";
+        $buffer = '';
 
         /**
          * Read in the file via Import::getNextChunk so that
@@ -98,7 +98,7 @@ class ImportXml extends ImportPlugin
          * result in increased performance without the need to
          * alter the code in any way. It's basically a freebee.
          */
-        $xml = @simplexml_load_string($buffer, "SimpleXMLElement", LIBXML_COMPACT);
+        $xml = @simplexml_load_string($buffer, 'SimpleXMLElement', LIBXML_COMPACT);
 
         unset($buffer);
 
@@ -208,16 +208,16 @@ class ImportXml extends ImportPlugin
                      *          into another database.
                      */
                     $attrs = $val2->attributes();
-                    $create[] = "USE "
+                    $create[] = 'USE '
                         . Util::backquote(
-                            $attrs["name"]
+                            $attrs['name']
                         );
 
                     foreach ($val2 as $val3) {
                         /**
                          * Remove the extra cosmetic spacing
                          */
-                        $val3 = str_replace("                ", "", (string) $val3);
+                        $val3 = str_replace('                ', '', (string) $val3);
                         $create[] = $val3;
                     }
                 }
diff --git a/libraries/classes/Plugins/Import/Upload/UploadApc.php b/libraries/classes/Plugins/Import/Upload/UploadApc.php
index ed7643c60c..71ec2454df 100644
--- a/libraries/classes/Plugins/Import/Upload/UploadApc.php
+++ b/libraries/classes/Plugins/Import/Upload/UploadApc.php
@@ -41,7 +41,7 @@ class UploadApc implements UploadInterface
     {
         global $SESSION_KEY;
 
-        if (trim($id) == "") {
+        if (trim($id) == '') {
             return null;
         }
         if (! array_key_exists($id, $_SESSION[$SESSION_KEY])) {
diff --git a/libraries/classes/Plugins/Import/Upload/UploadNoplugin.php b/libraries/classes/Plugins/Import/Upload/UploadNoplugin.php
index 89781a7013..e4c0bcab3f 100644
--- a/libraries/classes/Plugins/Import/Upload/UploadNoplugin.php
+++ b/libraries/classes/Plugins/Import/Upload/UploadNoplugin.php
@@ -41,7 +41,7 @@ class UploadNoplugin implements UploadInterface
     {
         global $SESSION_KEY;
 
-        if (trim($id) == "") {
+        if (trim($id) == '') {
             return null;
         }
         if (! array_key_exists($id, $_SESSION[$SESSION_KEY])) {
diff --git a/libraries/classes/Plugins/Import/Upload/UploadProgress.php b/libraries/classes/Plugins/Import/Upload/UploadProgress.php
index c25707adbf..05b234bd2a 100644
--- a/libraries/classes/Plugins/Import/Upload/UploadProgress.php
+++ b/libraries/classes/Plugins/Import/Upload/UploadProgress.php
@@ -41,7 +41,7 @@ class UploadProgress implements UploadInterface
     {
         global $SESSION_KEY;
 
-        if (trim($id) == "") {
+        if (trim($id) == '') {
             return null;
         }
 
diff --git a/libraries/classes/Plugins/Schema/Dia/TableStatsDia.php b/libraries/classes/Plugins/Schema/Dia/TableStatsDia.php
index 5028688254..94a74aa1e9 100644
--- a/libraries/classes/Plugins/Schema/Dia/TableStatsDia.php
+++ b/libraries/classes/Plugins/Schema/Dia/TableStatsDia.php
@@ -71,7 +71,7 @@ class TableStatsDia extends TableStats
     {
         ExportRelationSchema::dieSchema(
             $this->pageNumber,
-            "DIA",
+            'DIA',
             sprintf(__('The %s table doesn\'t exist!'), $this->tableName)
         );
     }
diff --git a/libraries/classes/Plugins/Schema/Eps/Eps.php b/libraries/classes/Plugins/Schema/Eps/Eps.php
index 6b43e9b1fc..e051b82334 100644
--- a/libraries/classes/Plugins/Schema/Eps/Eps.php
+++ b/libraries/classes/Plugins/Schema/Eps/Eps.php
@@ -36,7 +36,7 @@ class Eps
      */
     public function __construct()
     {
-        $this->stringCommands = "";
+        $this->stringCommands = '';
         $this->stringCommands .= "%!PS-Adobe-3.0 EPSF-3.0 \n";
     }
 
@@ -86,11 +86,11 @@ class Eps
     public function setOrientation($orientation)
     {
         $this->stringCommands .= "%%PageOrder: Ascend \n";
-        if ($orientation == "L") {
-            $orientation = "Landscape";
+        if ($orientation == 'L') {
+            $orientation = 'Landscape';
             $this->stringCommands .= '%%Orientation: ' . $orientation . "\n";
         } else {
-            $orientation = "Portrait";
+            $orientation = 'Portrait';
             $this->stringCommands .= '%%Orientation: ' . $orientation . "\n";
         }
         $this->stringCommands .= "%%EndComments \n";
@@ -112,9 +112,9 @@ class Eps
     {
         $this->font = $value;
         $this->fontSize = $size;
-        $this->stringCommands .= "/" . $value . " findfont   % Get the basic font\n";
-        $this->stringCommands .= ""
-            . $size . " scalefont            % Scale the font to $size points\n";
+        $this->stringCommands .= '/' . $value . " findfont   % Get the basic font\n";
+        $this->stringCommands .= ''
+            . $size . ' scalefont            % Scale the font to ' . $size . " points\n";
         $this->stringCommands
             .= "setfont                 % Make it the current font\n";
     }
@@ -192,10 +192,10 @@ class Eps
     {
         $this->stringCommands .= $lineWidth . " setlinewidth  \n";
         $this->stringCommands .= "newpath \n";
-        $this->stringCommands .= $x_from . " " . $y_from . " moveto \n";
-        $this->stringCommands .= "0 " . $y_to . " rlineto \n";
+        $this->stringCommands .= $x_from . ' ' . $y_from . " moveto \n";
+        $this->stringCommands .= '0 ' . $y_to . " rlineto \n";
         $this->stringCommands .= $x_to . " 0 rlineto \n";
-        $this->stringCommands .= "0 -" . $y_to . " rlineto \n";
+        $this->stringCommands .= '0 -' . $y_to . " rlineto \n";
         $this->stringCommands .= "closepath \n";
         $this->stringCommands .= "stroke \n";
     }
diff --git a/libraries/classes/Plugins/Schema/Eps/EpsRelationSchema.php b/libraries/classes/Plugins/Schema/Eps/EpsRelationSchema.php
index 435fdc165f..9addce5cd2 100644
--- a/libraries/classes/Plugins/Schema/Eps/EpsRelationSchema.php
+++ b/libraries/classes/Plugins/Schema/Eps/EpsRelationSchema.php
@@ -69,7 +69,7 @@ class EpsRelationSchema extends ExportRelationSchema
             )
         );
         $this->diagram->setAuthor('phpMyAdmin ' . PMA_VERSION);
-        $this->diagram->setDate(date("j F Y, g:i a"));
+        $this->diagram->setDate(date('j F Y, g:i a'));
         $this->diagram->setOrientation($this->orientation);
         $this->diagram->setFont('Verdana', '10');
 
diff --git a/libraries/classes/Plugins/Schema/Eps/TableStatsEps.php b/libraries/classes/Plugins/Schema/Eps/TableStatsEps.php
index 5b6a5c37c9..9341330506 100644
--- a/libraries/classes/Plugins/Schema/Eps/TableStatsEps.php
+++ b/libraries/classes/Plugins/Schema/Eps/TableStatsEps.php
@@ -89,7 +89,7 @@ class TableStatsEps extends TableStats
     {
         ExportRelationSchema::dieSchema(
             $this->pageNumber,
-            "EPS",
+            'EPS',
             sprintf(__('The %s table doesn\'t exist!'), $this->tableName)
         );
     }
diff --git a/libraries/classes/Plugins/Schema/ExportRelationSchema.php b/libraries/classes/Plugins/Schema/ExportRelationSchema.php
index e091c025b6..2a2da072e1 100644
--- a/libraries/classes/Plugins/Schema/ExportRelationSchema.php
+++ b/libraries/classes/Plugins/Schema/ExportRelationSchema.php
@@ -293,7 +293,7 @@ class ExportRelationSchema
      */
     public static function dieSchema($pageNumber, $type = '', $error_message = '')
     {
-        echo "<p><strong>" , __("SCHEMA ERROR: ") , $type , "</strong></p>" , "\n";
+        echo '<p><strong>' , __('SCHEMA ERROR: ') , $type , '</strong></p>' , "\n";
         if (! empty($error_message)) {
             $error_message = htmlspecialchars($error_message);
         }
diff --git a/libraries/classes/Plugins/Schema/Pdf/Pdf.php b/libraries/classes/Plugins/Schema/Pdf/Pdf.php
index 9367c42a96..3c0057c7d6 100644
--- a/libraries/classes/Plugins/Schema/Pdf/Pdf.php
+++ b/libraries/classes/Plugins/Schema/Pdf/Pdf.php
@@ -259,7 +259,7 @@ class Pdf extends PdfLib
         // This function must be named "Header" to work with the TCPDF library
         if ($this->_withDoc) {
             if ($this->_offline || $this->_pageNumber == -1) {
-                $pg_name = __("PDF export page");
+                $pg_name = __('PDF export page');
             } else {
                 $test_query = 'SELECT * FROM '
                     . Util::backquote($GLOBALS['cfgRelation']['db']) . '.'
diff --git a/libraries/classes/Plugins/Schema/Pdf/PdfRelationSchema.php b/libraries/classes/Plugins/Schema/Pdf/PdfRelationSchema.php
index e9f490e08b..722e8b7a24 100644
--- a/libraries/classes/Plugins/Schema/Pdf/PdfRelationSchema.php
+++ b/libraries/classes/Plugins/Schema/Pdf/PdfRelationSchema.php
@@ -501,7 +501,7 @@ class PdfRelationSchema extends ExportRelationSchema
             $this->diagram->Cell(
                 0,
                 6,
-                __('Page number:') . ' {' . sprintf("%02d", $i) . '}',
+                __('Page number:') . ' {' . sprintf('%02d', $i) . '}',
                 0,
                 0,
                 'R',
@@ -563,7 +563,7 @@ class PdfRelationSchema extends ExportRelationSchema
             $this->diagram->AddPage($this->orientation);
             $this->diagram->Bookmark($table);
             $this->diagram->setAlias(
-                '{' . sprintf("%02d", $z) . '}',
+                '{' . sprintf('%02d', $z) . '}',
                 $this->diagram->PageNo()
             );
             $this->diagram->PMA_links['RT'][$table]['-']
diff --git a/libraries/classes/Plugins/Schema/Pdf/TableStatsPdf.php b/libraries/classes/Plugins/Schema/Pdf/TableStatsPdf.php
index 03872b7761..9377e0938b 100644
--- a/libraries/classes/Plugins/Schema/Pdf/TableStatsPdf.php
+++ b/libraries/classes/Plugins/Schema/Pdf/TableStatsPdf.php
@@ -91,7 +91,7 @@ class TableStatsPdf extends TableStats
     {
         ExportRelationSchema::dieSchema(
             $this->pageNumber,
-            "PDF",
+            'PDF',
             sprintf(__('The %s table doesn\'t exist!'), $this->tableName)
         );
     }
diff --git a/libraries/classes/Plugins/Schema/SchemaDia.php b/libraries/classes/Plugins/Schema/SchemaDia.php
index ec9b20e213..e993b31e1e 100644
--- a/libraries/classes/Plugins/Schema/SchemaDia.php
+++ b/libraries/classes/Plugins/Schema/SchemaDia.php
@@ -48,16 +48,16 @@ class SchemaDia extends SchemaPlugin
         // $schemaPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // specific options main group
-        $specificOptions = new OptionsPropertyMainGroup("general_opts");
+        $specificOptions = new OptionsPropertyMainGroup('general_opts');
         // add options common to all plugins
         $this->addCommonOptions($specificOptions);
 
         $leaf = new SelectPropertyItem(
-            "orientation",
+            'orientation',
             __('Orientation')
         );
         $leaf->setValues(
@@ -69,7 +69,7 @@ class SchemaDia extends SchemaPlugin
         $specificOptions->addProperty($leaf);
 
         $leaf = new SelectPropertyItem(
-            "paper",
+            'paper',
             __('Paper size')
         );
         $leaf->setValues($this->getPaperSizeArray());
diff --git a/libraries/classes/Plugins/Schema/SchemaEps.php b/libraries/classes/Plugins/Schema/SchemaEps.php
index 453c130e35..1a06b808ce 100644
--- a/libraries/classes/Plugins/Schema/SchemaEps.php
+++ b/libraries/classes/Plugins/Schema/SchemaEps.php
@@ -49,11 +49,11 @@ class SchemaEps extends SchemaPlugin
         // $schemaPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // specific options main group
-        $specificOptions = new OptionsPropertyMainGroup("general_opts");
+        $specificOptions = new OptionsPropertyMainGroup('general_opts');
         // add options common to all plugins
         $this->addCommonOptions($specificOptions);
 
@@ -65,7 +65,7 @@ class SchemaEps extends SchemaPlugin
         $specificOptions->addProperty($leaf);
 
         $leaf = new SelectPropertyItem(
-            "orientation",
+            'orientation',
             __('Orientation')
         );
         $leaf->setValues(
diff --git a/libraries/classes/Plugins/Schema/SchemaPdf.php b/libraries/classes/Plugins/Schema/SchemaPdf.php
index 9dbab69773..0261d8309a 100644
--- a/libraries/classes/Plugins/Schema/SchemaPdf.php
+++ b/libraries/classes/Plugins/Schema/SchemaPdf.php
@@ -49,11 +49,11 @@ class SchemaPdf extends SchemaPlugin
         // $schemaPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // specific options main group
-        $specificOptions = new OptionsPropertyMainGroup("general_opts");
+        $specificOptions = new OptionsPropertyMainGroup('general_opts');
         // add options common to all plugins
         $this->addCommonOptions($specificOptions);
 
@@ -65,7 +65,7 @@ class SchemaPdf extends SchemaPlugin
         $specificOptions->addProperty($leaf);
 
         $leaf = new SelectPropertyItem(
-            "orientation",
+            'orientation',
             __('Orientation')
         );
         $leaf->setValues(
@@ -77,7 +77,7 @@ class SchemaPdf extends SchemaPlugin
         $specificOptions->addProperty($leaf);
 
         $leaf = new SelectPropertyItem(
-            "paper",
+            'paper',
             __('Paper size')
         );
         $leaf->setValues($this->getPaperSizeArray());
@@ -96,7 +96,7 @@ class SchemaPdf extends SchemaPlugin
         $specificOptions->addProperty($leaf);
 
         $leaf = new SelectPropertyItem(
-            "table_order",
+            'table_order',
             __('Order of the tables')
         );
         $leaf->setValues(
diff --git a/libraries/classes/Plugins/Schema/SchemaSvg.php b/libraries/classes/Plugins/Schema/SchemaSvg.php
index a7452f4e7a..537dc1c61b 100644
--- a/libraries/classes/Plugins/Schema/SchemaSvg.php
+++ b/libraries/classes/Plugins/Schema/SchemaSvg.php
@@ -48,11 +48,11 @@ class SchemaSvg extends SchemaPlugin
         // $schemaPluginProperties
         // this will be shown as "Format specific options"
         $exportSpecificOptions = new OptionsPropertyRootGroup(
-            "Format Specific Options"
+            'Format Specific Options'
         );
 
         // specific options main group
-        $specificOptions = new OptionsPropertyMainGroup("general_opts");
+        $specificOptions = new OptionsPropertyMainGroup('general_opts');
         // add options common to all plugins
         $this->addCommonOptions($specificOptions);
 
diff --git a/libraries/classes/Plugins/Schema/Svg/Svg.php b/libraries/classes/Plugins/Schema/Svg/Svg.php
index ab395319a7..d664446215 100644
--- a/libraries/classes/Plugins/Schema/Svg/Svg.php
+++ b/libraries/classes/Plugins/Schema/Svg/Svg.php
@@ -154,7 +154,7 @@ class Svg extends XMLWriter
         }
 
         if ($x != 0 || $y != 0) {
-            $this->writeAttribute('viewBox', "$x $y $width $height");
+            $this->writeAttribute('viewBox', sprintf('%d %d %d %d', $x, $y, $width, $height));
         }
         $this->writeAttribute('width', ($width - $x) . 'px');
         $this->writeAttribute('height', ($height - $y) . 'px');
diff --git a/libraries/classes/Plugins/Schema/Svg/TableStatsSvg.php b/libraries/classes/Plugins/Schema/Svg/TableStatsSvg.php
index 1bd34ee8e3..cffd40a547 100644
--- a/libraries/classes/Plugins/Schema/Svg/TableStatsSvg.php
+++ b/libraries/classes/Plugins/Schema/Svg/TableStatsSvg.php
@@ -89,7 +89,7 @@ class TableStatsSvg extends TableStats
     {
         ExportRelationSchema::dieSchema(
             $this->pageNumber,
-            "SVG",
+            'SVG',
             sprintf(__('The %s table doesn\'t exist!'), $this->tableName)
         );
     }
diff --git a/libraries/classes/Plugins/Transformations/Abs/Bool2TextTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/Bool2TextTransformationsPlugin.php
index 1bc297a41a..97dd32d715 100644
--- a/libraries/classes/Plugins/Transformations/Abs/Bool2TextTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/Bool2TextTransformationsPlugin.php
@@ -63,6 +63,6 @@ abstract class Bool2TextTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Bool2Text";
+        return 'Bool2Text';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/DateFormatTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/DateFormatTransformationsPlugin.php
index bb312b0788..c988d43def 100644
--- a/libraries/classes/Plugins/Transformations/Abs/DateFormatTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/DateFormatTransformationsPlugin.php
@@ -152,6 +152,6 @@ abstract class DateFormatTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Date Format";
+        return 'Date Format';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/DownloadTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/DownloadTransformationsPlugin.php
index 02ed96617f..c1c0ec5cc8 100644
--- a/libraries/classes/Plugins/Transformations/Abs/DownloadTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/DownloadTransformationsPlugin.php
@@ -91,6 +91,6 @@ abstract class DownloadTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Download";
+        return 'Download';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/ExternalTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/ExternalTransformationsPlugin.php
index 99ecf59a99..4ebde81009 100644
--- a/libraries/classes/Plugins/Transformations/Abs/ExternalTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/ExternalTransformationsPlugin.php
@@ -114,12 +114,12 @@ abstract class ExternalTransformationsPlugin extends TransformationsPlugin
         $newstring = '';
         $descriptorspec = [
             0 => [
-                "pipe",
-                "r",
+                'pipe',
+                'r',
             ],
             1 => [
-                "pipe",
-                "w",
+                'pipe',
+                'w',
             ],
         ];
         $process = proc_open($program . ' ' . $options[1], $descriptorspec, $pipes);
@@ -154,6 +154,6 @@ abstract class ExternalTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "External";
+        return 'External';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/FormattedTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/FormattedTransformationsPlugin.php
index 25eba5dc38..e101e5d94f 100644
--- a/libraries/classes/Plugins/Transformations/Abs/FormattedTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/FormattedTransformationsPlugin.php
@@ -59,6 +59,6 @@ abstract class FormattedTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Formatted";
+        return 'Formatted';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/HexTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/HexTransformationsPlugin.php
index 83243f0332..61a773a508 100644
--- a/libraries/classes/Plugins/Transformations/Abs/HexTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/HexTransformationsPlugin.php
@@ -65,6 +65,6 @@ abstract class HexTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Hex";
+        return 'Hex';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/ImageLinkTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/ImageLinkTransformationsPlugin.php
index 25402fdd43..81f3c98265 100644
--- a/libraries/classes/Plugins/Transformations/Abs/ImageLinkTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/ImageLinkTransformationsPlugin.php
@@ -62,6 +62,6 @@ abstract class ImageLinkTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "ImageLink";
+        return 'ImageLink';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/ImageUploadTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/ImageUploadTransformationsPlugin.php
index 408d624708..b4d794be83 100644
--- a/libraries/classes/Plugins/Transformations/Abs/ImageUploadTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/ImageUploadTransformationsPlugin.php
@@ -116,6 +116,6 @@ abstract class ImageUploadTransformationsPlugin extends IOTransformationsPlugin
      */
     public static function getName()
     {
-        return "Image upload";
+        return 'Image upload';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/InlineTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/InlineTransformationsPlugin.php
index e5eca514c4..fcec97becd 100644
--- a/libraries/classes/Plugins/Transformations/Abs/InlineTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/InlineTransformationsPlugin.php
@@ -73,6 +73,6 @@ abstract class InlineTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Inline";
+        return 'Inline';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/LongToIPv4TransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/LongToIPv4TransformationsPlugin.php
index d3627dd5c7..1a09f4455d 100644
--- a/libraries/classes/Plugins/Transformations/Abs/LongToIPv4TransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/LongToIPv4TransformationsPlugin.php
@@ -60,6 +60,6 @@ abstract class LongToIPv4TransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Long To IPv4";
+        return 'Long To IPv4';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/PreApPendTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/PreApPendTransformationsPlugin.php
index 702ad9de69..e042d0fb2a 100644
--- a/libraries/classes/Plugins/Transformations/Abs/PreApPendTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/PreApPendTransformationsPlugin.php
@@ -62,6 +62,6 @@ abstract class PreApPendTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "PreApPend";
+        return 'PreApPend';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/RegexValidationTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/RegexValidationTransformationsPlugin.php
index 5d04c3caa3..ba318b1703 100644
--- a/libraries/classes/Plugins/Transformations/Abs/RegexValidationTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/RegexValidationTransformationsPlugin.php
@@ -68,6 +68,6 @@ abstract class RegexValidationTransformationsPlugin extends IOTransformationsPlu
      */
     public static function getName()
     {
-        return "Regex Validation";
+        return 'Regex Validation';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/SQLTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/SQLTransformationsPlugin.php
index 130f8d0db6..84c0dbdd67 100644
--- a/libraries/classes/Plugins/Transformations/Abs/SQLTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/SQLTransformationsPlugin.php
@@ -57,6 +57,6 @@ abstract class SQLTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "SQL";
+        return 'SQL';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/SubstringTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/SubstringTransformationsPlugin.php
index cd386d1eb5..d951a21ee0 100644
--- a/libraries/classes/Plugins/Transformations/Abs/SubstringTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/SubstringTransformationsPlugin.php
@@ -87,6 +87,6 @@ abstract class SubstringTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Substring";
+        return 'Substring';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/TextFileUploadTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/TextFileUploadTransformationsPlugin.php
index 628d10269a..2afb99374e 100644
--- a/libraries/classes/Plugins/Transformations/Abs/TextFileUploadTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/TextFileUploadTransformationsPlugin.php
@@ -97,6 +97,6 @@ abstract class TextFileUploadTransformationsPlugin extends IOTransformationsPlug
      */
     public static function getName()
     {
-        return "Text file upload";
+        return 'Text file upload';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/TextImageLinkTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/TextImageLinkTransformationsPlugin.php
index 3fb5a6878d..759d2f743e 100644
--- a/libraries/classes/Plugins/Transformations/Abs/TextImageLinkTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/TextImageLinkTransformationsPlugin.php
@@ -74,6 +74,6 @@ abstract class TextImageLinkTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Image Link";
+        return 'Image Link';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Abs/TextLinkTransformationsPlugin.php b/libraries/classes/Plugins/Transformations/Abs/TextLinkTransformationsPlugin.php
index 61b3a9c581..4e2d60f843 100644
--- a/libraries/classes/Plugins/Transformations/Abs/TextLinkTransformationsPlugin.php
+++ b/libraries/classes/Plugins/Transformations/Abs/TextLinkTransformationsPlugin.php
@@ -71,6 +71,6 @@ abstract class TextLinkTransformationsPlugin extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "TextLink";
+        return 'TextLink';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Input/Image_JPEG_Upload.php b/libraries/classes/Plugins/Transformations/Input/Image_JPEG_Upload.php
index d30086a09a..ad4078f2c6 100644
--- a/libraries/classes/Plugins/Transformations/Input/Image_JPEG_Upload.php
+++ b/libraries/classes/Plugins/Transformations/Input/Image_JPEG_Upload.php
@@ -28,7 +28,7 @@ class Image_JPEG_Upload extends ImageUploadTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Image";
+        return 'Image';
     }
 
     /**
@@ -38,6 +38,6 @@ class Image_JPEG_Upload extends ImageUploadTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "JPEG";
+        return 'JPEG';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Input/Text_Plain_FileUpload.php b/libraries/classes/Plugins/Transformations/Input/Text_Plain_FileUpload.php
index faf3edc979..e9dae72ec1 100644
--- a/libraries/classes/Plugins/Transformations/Input/Text_Plain_FileUpload.php
+++ b/libraries/classes/Plugins/Transformations/Input/Text_Plain_FileUpload.php
@@ -27,7 +27,7 @@ class Text_Plain_FileUpload extends TextFileUploadTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -37,6 +37,6 @@ class Text_Plain_FileUpload extends TextFileUploadTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Input/Text_Plain_Iptobinary.php b/libraries/classes/Plugins/Transformations/Input/Text_Plain_Iptobinary.php
index b3453ff77f..6c1e8c5824 100644
--- a/libraries/classes/Plugins/Transformations/Input/Text_Plain_Iptobinary.php
+++ b/libraries/classes/Plugins/Transformations/Input/Text_Plain_Iptobinary.php
@@ -115,7 +115,7 @@ class Text_Plain_Iptobinary extends IOTransformationsPlugin
      */
     public static function getName()
     {
-        return "IPv4/IPv6 To Binary";
+        return 'IPv4/IPv6 To Binary';
     }
 
     /**
@@ -125,7 +125,7 @@ class Text_Plain_Iptobinary extends IOTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -135,6 +135,6 @@ class Text_Plain_Iptobinary extends IOTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Input/Text_Plain_JsonEditor.php b/libraries/classes/Plugins/Transformations/Input/Text_Plain_JsonEditor.php
index f819901721..43172d29e8 100644
--- a/libraries/classes/Plugins/Transformations/Input/Text_Plain_JsonEditor.php
+++ b/libraries/classes/Plugins/Transformations/Input/Text_Plain_JsonEditor.php
@@ -59,7 +59,7 @@ class Text_Plain_JsonEditor extends CodeMirrorEditorTransformationPlugin
      */
     public static function getName()
     {
-        return "JSON";
+        return 'JSON';
     }
 
     /**
@@ -69,7 +69,7 @@ class Text_Plain_JsonEditor extends CodeMirrorEditorTransformationPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -79,6 +79,6 @@ class Text_Plain_JsonEditor extends CodeMirrorEditorTransformationPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Input/Text_Plain_RegexValidation.php b/libraries/classes/Plugins/Transformations/Input/Text_Plain_RegexValidation.php
index 6cb012fe4b..e7959f9ef8 100644
--- a/libraries/classes/Plugins/Transformations/Input/Text_Plain_RegexValidation.php
+++ b/libraries/classes/Plugins/Transformations/Input/Text_Plain_RegexValidation.php
@@ -28,7 +28,7 @@ class Text_Plain_RegexValidation extends RegexValidationTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -38,6 +38,6 @@ class Text_Plain_RegexValidation extends RegexValidationTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Input/Text_Plain_SqlEditor.php b/libraries/classes/Plugins/Transformations/Input/Text_Plain_SqlEditor.php
index e48234bbd3..3164ca9657 100644
--- a/libraries/classes/Plugins/Transformations/Input/Text_Plain_SqlEditor.php
+++ b/libraries/classes/Plugins/Transformations/Input/Text_Plain_SqlEditor.php
@@ -59,7 +59,7 @@ class Text_Plain_SqlEditor extends CodeMirrorEditorTransformationPlugin
      */
     public static function getName()
     {
-        return "SQL";
+        return 'SQL';
     }
 
     /**
@@ -69,7 +69,7 @@ class Text_Plain_SqlEditor extends CodeMirrorEditorTransformationPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -79,6 +79,6 @@ class Text_Plain_SqlEditor extends CodeMirrorEditorTransformationPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Input/Text_Plain_XmlEditor.php b/libraries/classes/Plugins/Transformations/Input/Text_Plain_XmlEditor.php
index e62a4eeadd..81577b45b1 100644
--- a/libraries/classes/Plugins/Transformations/Input/Text_Plain_XmlEditor.php
+++ b/libraries/classes/Plugins/Transformations/Input/Text_Plain_XmlEditor.php
@@ -59,7 +59,7 @@ class Text_Plain_XmlEditor extends CodeMirrorEditorTransformationPlugin
      */
     public static function getName()
     {
-        return "XML";
+        return 'XML';
     }
 
     /**
@@ -69,7 +69,7 @@ class Text_Plain_XmlEditor extends CodeMirrorEditorTransformationPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -79,6 +79,6 @@ class Text_Plain_XmlEditor extends CodeMirrorEditorTransformationPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Application_Octetstream_Download.php b/libraries/classes/Plugins/Transformations/Output/Application_Octetstream_Download.php
index 109efcd630..8201536233 100644
--- a/libraries/classes/Plugins/Transformations/Output/Application_Octetstream_Download.php
+++ b/libraries/classes/Plugins/Transformations/Output/Application_Octetstream_Download.php
@@ -27,7 +27,7 @@ class Application_Octetstream_Download extends DownloadTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Application";
+        return 'Application';
     }
 
     /**
@@ -37,6 +37,6 @@ class Application_Octetstream_Download extends DownloadTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "OctetStream";
+        return 'OctetStream';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Application_Octetstream_Hex.php b/libraries/classes/Plugins/Transformations/Output/Application_Octetstream_Hex.php
index 8aaafa1ca9..92a8597d75 100644
--- a/libraries/classes/Plugins/Transformations/Output/Application_Octetstream_Hex.php
+++ b/libraries/classes/Plugins/Transformations/Output/Application_Octetstream_Hex.php
@@ -27,7 +27,7 @@ class Application_Octetstream_Hex extends HexTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Application";
+        return 'Application';
     }
 
     /**
@@ -37,6 +37,6 @@ class Application_Octetstream_Hex extends HexTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "OctetStream";
+        return 'OctetStream';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Image_JPEG_Inline.php b/libraries/classes/Plugins/Transformations/Output/Image_JPEG_Inline.php
index 23206b3372..38b21edc97 100644
--- a/libraries/classes/Plugins/Transformations/Output/Image_JPEG_Inline.php
+++ b/libraries/classes/Plugins/Transformations/Output/Image_JPEG_Inline.php
@@ -27,7 +27,7 @@ class Image_JPEG_Inline extends InlineTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Image";
+        return 'Image';
     }
 
     /**
@@ -37,6 +37,6 @@ class Image_JPEG_Inline extends InlineTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "JPEG";
+        return 'JPEG';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Image_JPEG_Link.php b/libraries/classes/Plugins/Transformations/Output/Image_JPEG_Link.php
index 8bf41d336a..c2c5b56ee0 100644
--- a/libraries/classes/Plugins/Transformations/Output/Image_JPEG_Link.php
+++ b/libraries/classes/Plugins/Transformations/Output/Image_JPEG_Link.php
@@ -27,7 +27,7 @@ class Image_JPEG_Link extends ImageLinkTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Image";
+        return 'Image';
     }
 
     /**
@@ -37,6 +37,6 @@ class Image_JPEG_Link extends ImageLinkTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "JPEG";
+        return 'JPEG';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Image_PNG_Inline.php b/libraries/classes/Plugins/Transformations/Output/Image_PNG_Inline.php
index cb549f21bc..a5212fbb1f 100644
--- a/libraries/classes/Plugins/Transformations/Output/Image_PNG_Inline.php
+++ b/libraries/classes/Plugins/Transformations/Output/Image_PNG_Inline.php
@@ -27,7 +27,7 @@ class Image_PNG_Inline extends InlineTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Image";
+        return 'Image';
     }
 
     /**
@@ -37,6 +37,6 @@ class Image_PNG_Inline extends InlineTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "PNG";
+        return 'PNG';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Octetstream_Sql.php b/libraries/classes/Plugins/Transformations/Output/Text_Octetstream_Sql.php
index 0dab56e2a2..0849c1a6d1 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Octetstream_Sql.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Octetstream_Sql.php
@@ -27,7 +27,7 @@ class Text_Octetstream_Sql extends SQLTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -37,6 +37,6 @@ class Text_Octetstream_Sql extends SQLTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Octetstream";
+        return 'Octetstream';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Binarytoip.php b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Binarytoip.php
index 649aaad164..98a0b71478 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Binarytoip.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Binarytoip.php
@@ -71,7 +71,7 @@ class Text_Plain_Binarytoip extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "Binary To IPv4/IPv6";
+        return 'Binary To IPv4/IPv6';
     }
 
     /**
@@ -81,7 +81,7 @@ class Text_Plain_Binarytoip extends TransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -91,6 +91,6 @@ class Text_Plain_Binarytoip extends TransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Bool2Text.php b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Bool2Text.php
index 9250eea0ae..8e60570001 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Bool2Text.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Bool2Text.php
@@ -29,7 +29,7 @@ class Text_Plain_Bool2Text extends Bool2TextTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -39,6 +39,6 @@ class Text_Plain_Bool2Text extends Bool2TextTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Dateformat.php b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Dateformat.php
index eb70bee1e9..d8e11ac8e5 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Dateformat.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Dateformat.php
@@ -27,7 +27,7 @@ class Text_Plain_Dateformat extends DateFormatTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -37,6 +37,6 @@ class Text_Plain_Dateformat extends DateFormatTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Plain_External.php b/libraries/classes/Plugins/Transformations/Output/Text_Plain_External.php
index 1839c89d3f..c8f292fe6f 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Plain_External.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Plain_External.php
@@ -27,7 +27,7 @@ class Text_Plain_External extends ExternalTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -37,6 +37,6 @@ class Text_Plain_External extends ExternalTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Formatted.php b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Formatted.php
index 70d3a3cfc9..7b6ca66e64 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Formatted.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Formatted.php
@@ -27,7 +27,7 @@ class Text_Plain_Formatted extends FormattedTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -37,6 +37,6 @@ class Text_Plain_Formatted extends FormattedTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Imagelink.php b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Imagelink.php
index 24b84a265f..2f9ff93ffb 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Imagelink.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Imagelink.php
@@ -27,7 +27,7 @@ class Text_Plain_Imagelink extends TextImageLinkTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -37,6 +37,6 @@ class Text_Plain_Imagelink extends TextImageLinkTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Json.php b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Json.php
index 7e2475c624..278dc4036d 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Json.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Json.php
@@ -75,7 +75,7 @@ class Text_Plain_Json extends TransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -85,7 +85,7 @@ class Text_Plain_Json extends TransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 
     /**
@@ -95,6 +95,6 @@ class Text_Plain_Json extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "JSON";
+        return 'JSON';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Sql.php b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Sql.php
index c61b42eda8..b222d2d655 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Sql.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Sql.php
@@ -44,7 +44,7 @@ class Text_Plain_Sql extends SQLTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -54,6 +54,6 @@ class Text_Plain_Sql extends SQLTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Xml.php b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Xml.php
index 01bbd9f1b6..851757a006 100644
--- a/libraries/classes/Plugins/Transformations/Output/Text_Plain_Xml.php
+++ b/libraries/classes/Plugins/Transformations/Output/Text_Plain_Xml.php
@@ -75,7 +75,7 @@ class Text_Plain_Xml extends TransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -85,7 +85,7 @@ class Text_Plain_Xml extends TransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 
     /**
@@ -95,6 +95,6 @@ class Text_Plain_Xml extends TransformationsPlugin
      */
     public static function getName()
     {
-        return "XML";
+        return 'XML';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Text_Plain_Link.php b/libraries/classes/Plugins/Transformations/Text_Plain_Link.php
index e31862933f..1283663dd2 100644
--- a/libraries/classes/Plugins/Transformations/Text_Plain_Link.php
+++ b/libraries/classes/Plugins/Transformations/Text_Plain_Link.php
@@ -27,7 +27,7 @@ class Text_Plain_Link extends TextLinkTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -37,6 +37,6 @@ class Text_Plain_Link extends TextLinkTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Text_Plain_Longtoipv4.php b/libraries/classes/Plugins/Transformations/Text_Plain_Longtoipv4.php
index ce4b9da427..d80b66edee 100644
--- a/libraries/classes/Plugins/Transformations/Text_Plain_Longtoipv4.php
+++ b/libraries/classes/Plugins/Transformations/Text_Plain_Longtoipv4.php
@@ -27,7 +27,7 @@ class Text_Plain_Longtoipv4 extends LongToIPv4TransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -37,6 +37,6 @@ class Text_Plain_Longtoipv4 extends LongToIPv4TransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Text_Plain_PreApPend.php b/libraries/classes/Plugins/Transformations/Text_Plain_PreApPend.php
index 171f184229..3f23e60d05 100644
--- a/libraries/classes/Plugins/Transformations/Text_Plain_PreApPend.php
+++ b/libraries/classes/Plugins/Transformations/Text_Plain_PreApPend.php
@@ -28,7 +28,7 @@ class Text_Plain_PreApPend extends PreApPendTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -38,6 +38,6 @@ class Text_Plain_PreApPend extends PreApPendTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Plugins/Transformations/Text_Plain_Substring.php b/libraries/classes/Plugins/Transformations/Text_Plain_Substring.php
index b598e85a7e..76ab3fbfd9 100644
--- a/libraries/classes/Plugins/Transformations/Text_Plain_Substring.php
+++ b/libraries/classes/Plugins/Transformations/Text_Plain_Substring.php
@@ -27,7 +27,7 @@ class Text_Plain_Substring extends SubstringTransformationsPlugin
      */
     public static function getMIMEType()
     {
-        return "Text";
+        return 'Text';
     }
 
     /**
@@ -37,6 +37,6 @@ class Text_Plain_Substring extends SubstringTransformationsPlugin
      */
     public static function getMIMESubtype()
     {
-        return "Plain";
+        return 'Plain';
     }
 }
diff --git a/libraries/classes/Properties/Options/Groups/OptionsPropertyMainGroup.php b/libraries/classes/Properties/Options/Groups/OptionsPropertyMainGroup.php
index 0abd2e306a..d08a9c1db0 100644
--- a/libraries/classes/Properties/Options/Groups/OptionsPropertyMainGroup.php
+++ b/libraries/classes/Properties/Options/Groups/OptionsPropertyMainGroup.php
@@ -29,6 +29,6 @@ class OptionsPropertyMainGroup extends OptionsPropertyGroup
      */
     public function getItemType()
     {
-        return "main";
+        return 'main';
     }
 }
diff --git a/libraries/classes/Properties/Options/Groups/OptionsPropertyRootGroup.php b/libraries/classes/Properties/Options/Groups/OptionsPropertyRootGroup.php
index ffecafaa39..f29caef1d1 100644
--- a/libraries/classes/Properties/Options/Groups/OptionsPropertyRootGroup.php
+++ b/libraries/classes/Properties/Options/Groups/OptionsPropertyRootGroup.php
@@ -29,6 +29,6 @@ class OptionsPropertyRootGroup extends OptionsPropertyGroup
      */
     public function getItemType()
     {
-        return "root";
+        return 'root';
     }
 }
diff --git a/libraries/classes/Properties/Options/Groups/OptionsPropertySubgroup.php b/libraries/classes/Properties/Options/Groups/OptionsPropertySubgroup.php
index 3a372195d6..cfe8ecfaea 100644
--- a/libraries/classes/Properties/Options/Groups/OptionsPropertySubgroup.php
+++ b/libraries/classes/Properties/Options/Groups/OptionsPropertySubgroup.php
@@ -38,7 +38,7 @@ class OptionsPropertySubgroup extends OptionsPropertyGroup
      */
     public function getItemType()
     {
-        return "subgroup";
+        return 'subgroup';
     }
 
     /**
diff --git a/libraries/classes/Properties/Options/Items/BoolPropertyItem.php b/libraries/classes/Properties/Options/Items/BoolPropertyItem.php
index 86f90d1af7..9372c98d73 100644
--- a/libraries/classes/Properties/Options/Items/BoolPropertyItem.php
+++ b/libraries/classes/Properties/Options/Items/BoolPropertyItem.php
@@ -29,6 +29,6 @@ class BoolPropertyItem extends OptionsPropertyOneItem
      */
     public function getItemType()
     {
-        return "bool";
+        return 'bool';
     }
 }
diff --git a/libraries/classes/Properties/Options/Items/DocPropertyItem.php b/libraries/classes/Properties/Options/Items/DocPropertyItem.php
index 6657ecd94f..2675b1bba1 100644
--- a/libraries/classes/Properties/Options/Items/DocPropertyItem.php
+++ b/libraries/classes/Properties/Options/Items/DocPropertyItem.php
@@ -29,6 +29,6 @@ class DocPropertyItem extends OptionsPropertyOneItem
      */
     public function getItemType()
     {
-        return "doc";
+        return 'doc';
     }
 }
diff --git a/libraries/classes/Properties/Options/Items/HiddenPropertyItem.php b/libraries/classes/Properties/Options/Items/HiddenPropertyItem.php
index ccffb26f61..e61d730884 100644
--- a/libraries/classes/Properties/Options/Items/HiddenPropertyItem.php
+++ b/libraries/classes/Properties/Options/Items/HiddenPropertyItem.php
@@ -29,6 +29,6 @@ class HiddenPropertyItem extends OptionsPropertyOneItem
      */
     public function getItemType()
     {
-        return "hidden";
+        return 'hidden';
     }
 }
diff --git a/libraries/classes/Properties/Options/Items/MessageOnlyPropertyItem.php b/libraries/classes/Properties/Options/Items/MessageOnlyPropertyItem.php
index 4f500bcd76..28544e2bb9 100644
--- a/libraries/classes/Properties/Options/Items/MessageOnlyPropertyItem.php
+++ b/libraries/classes/Properties/Options/Items/MessageOnlyPropertyItem.php
@@ -29,6 +29,6 @@ class MessageOnlyPropertyItem extends OptionsPropertyOneItem
      */
     public function getItemType()
     {
-        return "messageOnly";
+        return 'messageOnly';
     }
 }
diff --git a/libraries/classes/Properties/Options/Items/NumberPropertyItem.php b/libraries/classes/Properties/Options/Items/NumberPropertyItem.php
index 50d65fbf6e..62fd923b73 100644
--- a/libraries/classes/Properties/Options/Items/NumberPropertyItem.php
+++ b/libraries/classes/Properties/Options/Items/NumberPropertyItem.php
@@ -29,6 +29,6 @@ class NumberPropertyItem extends OptionsPropertyOneItem
      */
     public function getItemType()
     {
-        return "number";
+        return 'number';
     }
 }
diff --git a/libraries/classes/Properties/Options/Items/RadioPropertyItem.php b/libraries/classes/Properties/Options/Items/RadioPropertyItem.php
index 45a4dfc99f..e532e13897 100644
--- a/libraries/classes/Properties/Options/Items/RadioPropertyItem.php
+++ b/libraries/classes/Properties/Options/Items/RadioPropertyItem.php
@@ -29,6 +29,6 @@ class RadioPropertyItem extends OptionsPropertyOneItem
      */
     public function getItemType()
     {
-        return "radio";
+        return 'radio';
     }
 }
diff --git a/libraries/classes/Properties/Options/Items/SelectPropertyItem.php b/libraries/classes/Properties/Options/Items/SelectPropertyItem.php
index eae2194026..e150428a8f 100644
--- a/libraries/classes/Properties/Options/Items/SelectPropertyItem.php
+++ b/libraries/classes/Properties/Options/Items/SelectPropertyItem.php
@@ -29,6 +29,6 @@ class SelectPropertyItem extends OptionsPropertyOneItem
      */
     public function getItemType()
     {
-        return "select";
+        return 'select';
     }
 }
diff --git a/libraries/classes/Properties/Options/Items/TextPropertyItem.php b/libraries/classes/Properties/Options/Items/TextPropertyItem.php
index 5fc16760b1..a7e3b2ab66 100644
--- a/libraries/classes/Properties/Options/Items/TextPropertyItem.php
+++ b/libraries/classes/Properties/Options/Items/TextPropertyItem.php
@@ -29,6 +29,6 @@ class TextPropertyItem extends OptionsPropertyOneItem
      */
     public function getItemType()
     {
-        return "text";
+        return 'text';
     }
 }
diff --git a/libraries/classes/Properties/Options/OptionsPropertyItem.php b/libraries/classes/Properties/Options/OptionsPropertyItem.php
index 132eb99016..557d524cc4 100644
--- a/libraries/classes/Properties/Options/OptionsPropertyItem.php
+++ b/libraries/classes/Properties/Options/OptionsPropertyItem.php
@@ -130,6 +130,6 @@ abstract class OptionsPropertyItem extends PropertyItem
      */
     public function getPropertyType()
     {
-        return "options";
+        return 'options';
     }
 }
diff --git a/libraries/classes/Properties/Plugins/ExportPluginProperties.php b/libraries/classes/Properties/Plugins/ExportPluginProperties.php
index f54c9cfce0..dd9841b488 100644
--- a/libraries/classes/Properties/Plugins/ExportPluginProperties.php
+++ b/libraries/classes/Properties/Plugins/ExportPluginProperties.php
@@ -36,7 +36,7 @@ class ExportPluginProperties extends PluginPropertyItem
      */
     public function getItemType()
     {
-        return "export";
+        return 'export';
     }
 
     /**
diff --git a/libraries/classes/Properties/Plugins/ImportPluginProperties.php b/libraries/classes/Properties/Plugins/ImportPluginProperties.php
index 758ccf2a40..4ea4ba0913 100644
--- a/libraries/classes/Properties/Plugins/ImportPluginProperties.php
+++ b/libraries/classes/Properties/Plugins/ImportPluginProperties.php
@@ -27,6 +27,6 @@ class ImportPluginProperties extends PluginPropertyItem
      */
     public function getItemType()
     {
-        return "import";
+        return 'import';
     }
 }
diff --git a/libraries/classes/Properties/Plugins/PluginPropertyItem.php b/libraries/classes/Properties/Plugins/PluginPropertyItem.php
index f72f6e933b..442ef86761 100644
--- a/libraries/classes/Properties/Plugins/PluginPropertyItem.php
+++ b/libraries/classes/Properties/Plugins/PluginPropertyItem.php
@@ -171,6 +171,6 @@ abstract class PluginPropertyItem extends PropertyItem
      */
     public function getPropertyType()
     {
-        return "plugin";
+        return 'plugin';
     }
 }
diff --git a/libraries/classes/Properties/Plugins/SchemaPluginProperties.php b/libraries/classes/Properties/Plugins/SchemaPluginProperties.php
index d46f3be4fc..092c978f9e 100644
--- a/libraries/classes/Properties/Plugins/SchemaPluginProperties.php
+++ b/libraries/classes/Properties/Plugins/SchemaPluginProperties.php
@@ -30,7 +30,7 @@ class SchemaPluginProperties extends PluginPropertyItem
      */
     public function getItemType()
     {
-        return "schema";
+        return 'schema';
     }
 
     /**
diff --git a/libraries/classes/RecentFavoriteTable.php b/libraries/classes/RecentFavoriteTable.php
index 46f4c689e7..b522d660f5 100644
--- a/libraries/classes/RecentFavoriteTable.php
+++ b/libraries/classes/RecentFavoriteTable.php
@@ -104,7 +104,7 @@ class RecentFavoriteTable
     {
         // Read from phpMyAdmin database, if recent tables is not in session
         $sql_query
-            = " SELECT `tables` FROM " . $this->_getPmaTable() .
+            = ' SELECT `tables` FROM ' . $this->_getPmaTable() .
             " WHERE `username` = '" . $GLOBALS['dbi']->escapeString($GLOBALS['cfg']['Server']['user']) . "'";
 
         $return = [];
@@ -127,7 +127,7 @@ class RecentFavoriteTable
     {
         $username = $GLOBALS['cfg']['Server']['user'];
         $sql_query
-            = " REPLACE INTO " . $this->_getPmaTable() . " (`username`, `tables`)" .
+            = ' REPLACE INTO ' . $this->_getPmaTable() . ' (`username`, `tables`)' .
                 " VALUES ('" . $GLOBALS['dbi']->escapeString($username) . "', '"
                 . $GLOBALS['dbi']->escapeString(
                     json_encode($this->_tables)
@@ -210,9 +210,9 @@ class RecentFavoriteTable
                         'remove_favorite' => true,
                     ]);
                     $html .= 'href="' . $fav_rm_url
-                        . '" title="' . __("Remove from Favorites")
+                        . '" title="' . __('Remove from Favorites')
                         . '" data-favtargetn="'
-                        . md5($table['db'] . "." . $table['table'])
+                        . md5($table['db'] . '.' . $table['table'])
                         . '" >'
                         . Generator::getIcon('b_favorite')
                         . '</a>';
@@ -390,7 +390,7 @@ class RecentFavoriteTable
         if (! empty($cfgRelation['db'])
             && ! empty($cfgRelation[$this->_tableType])
         ) {
-            return Util::backquote($cfgRelation['db']) . "."
+            return Util::backquote($cfgRelation['db']) . '.'
                 . Util::backquote($cfgRelation[$this->_tableType]);
         }
         return null;
diff --git a/libraries/classes/Relation.php b/libraries/classes/Relation.php
index 4cb00234f8..913e0000a7 100644
--- a/libraries/classes/Relation.php
+++ b/libraries/classes/Relation.php
@@ -775,8 +775,8 @@ class Relation
         // From 4.3, new input oriented transformation feature was introduced.
         // Check whether column_info table has input transformation columns
         $new_cols = [
-            "input_transformation",
-            "input_transformation_options",
+            'input_transformation',
+            'input_transformation_options',
         ];
         $query = 'SHOW COLUMNS FROM '
             . Util::backquote($GLOBALS['cfg']['Server']['pmadb'])
@@ -1025,10 +1025,10 @@ class Relation
 
         if ($cfgRelation['commwork']) {
             // pmadb internal db comment
-            $com_qry = "
+            $com_qry = '
                 SELECT `comment`
-                FROM " . Util::backquote($cfgRelation['db'])
-                    . "." . Util::backquote($cfgRelation['column_info'])
+                FROM ' . Util::backquote($cfgRelation['db'])
+                    . '.' . Util::backquote($cfgRelation['column_info'])
                     . "
                 WHERE db_name     = '" . $this->dbi->escapeString($db) . "'
                     AND table_name  = ''
@@ -1063,10 +1063,10 @@ class Relation
 
         if ($cfgRelation['commwork']) {
             // pmadb internal db comment
-            $com_qry = "
+            $com_qry = '
                 SELECT `db_name`, `comment`
-                FROM " . Util::backquote($cfgRelation['db'])
-                    . "." . Util::backquote($cfgRelation['column_info'])
+                FROM ' . Util::backquote($cfgRelation['db'])
+                    . '.' . Util::backquote($cfgRelation['column_info'])
                     . "
                 WHERE `column_name` = '(db_comment)'";
             $com_rs = $this->queryAsControlUser(
@@ -1333,7 +1333,7 @@ class Relation
                 $key = htmlspecialchars($key);
             } else {
                 $key = '0x' . bin2hex($key);
-                if (false !== strpos($data, "0x")) {
+                if (false !== strpos($data, '0x')) {
                     $selected = ($key == trim($data));
                 } else {
                     $selected = ($key == '0x' . $data);
@@ -1789,8 +1789,8 @@ class Relation
             } else {
                 // if the table is moved out of the database we can no loger keep the
                 // record for table coordinate
-                $remove_query = "DELETE FROM "
-                    . Util::backquote($GLOBALS['cfgRelation']['db']) . "."
+                $remove_query = 'DELETE FROM '
+                    . Util::backquote($GLOBALS['cfgRelation']['db']) . '.'
                     . Util::backquote($GLOBALS['cfgRelation']['table_coords'])
                     . " WHERE db_name  = '" . $this->dbi->escapeString($source_db) . "'"
                     . " AND table_name = '" . $this->dbi->escapeString($source_table)
@@ -1824,8 +1824,8 @@ class Relation
             );
 
             // update data for hidden table
-            $query = "UPDATE "
-                . Util::backquote($GLOBALS['cfgRelation']['db']) . "."
+            $query = 'UPDATE '
+                . Util::backquote($GLOBALS['cfgRelation']['db']) . '.'
                 . Util::backquote(
                     $GLOBALS['cfgRelation']['navigationhiding']
                 )
@@ -1882,9 +1882,9 @@ class Relation
     {
         $child_references = [];
         if (! $GLOBALS['cfg']['Server']['DisableIS']) {
-            $rel_query = "SELECT `column_name`, `table_name`,"
-                . " `table_schema`, `referenced_column_name`"
-                . " FROM `information_schema`.`key_column_usage`"
+            $rel_query = 'SELECT `column_name`, `table_name`,'
+                . ' `table_schema`, `referenced_column_name`'
+                . ' FROM `information_schema`.`key_column_usage`'
                 . " WHERE `referenced_table_name` = '"
                 . $this->dbi->escapeString($table) . "'"
                 . " AND `referenced_table_schema` = '"
@@ -2046,7 +2046,7 @@ class Relation
      */
     public function createPmaDatabase()
     {
-        $this->dbi->tryQuery("CREATE DATABASE IF NOT EXISTS `phpmyadmin`");
+        $this->dbi->tryQuery('CREATE DATABASE IF NOT EXISTS `phpmyadmin`');
         if ($error = $this->dbi->getError()) {
             if ($GLOBALS['errno'] == 1044) {
                 $GLOBALS['message'] =    __(
diff --git a/libraries/classes/RelationCleanup.php b/libraries/classes/RelationCleanup.php
index 121bb64feb..ce002d40ef 100644
--- a/libraries/classes/RelationCleanup.php
+++ b/libraries/classes/RelationCleanup.php
@@ -299,90 +299,90 @@ class RelationCleanup
         $cfgRelation = $this->relation->getRelationsParam();
 
         if ($cfgRelation['bookmarkwork']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['bookmark'])
+                . '.' . Util::backquote($cfgRelation['bookmark'])
                 . " WHERE `user`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
         }
 
         if ($cfgRelation['historywork']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['history'])
+                . '.' . Util::backquote($cfgRelation['history'])
                 . " WHERE `username`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
         }
 
         if ($cfgRelation['recentwork']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['recent'])
+                . '.' . Util::backquote($cfgRelation['recent'])
                 . " WHERE `username`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
         }
 
         if ($cfgRelation['favoritework']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['favorite'])
+                . '.' . Util::backquote($cfgRelation['favorite'])
                 . " WHERE `username`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
         }
 
         if ($cfgRelation['uiprefswork']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['table_uiprefs'])
+                . '.' . Util::backquote($cfgRelation['table_uiprefs'])
                 . " WHERE `username`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
         }
 
         if ($cfgRelation['userconfigwork']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['userconfig'])
+                . '.' . Util::backquote($cfgRelation['userconfig'])
                 . " WHERE `username`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
         }
 
         if ($cfgRelation['menuswork']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['users'])
+                . '.' . Util::backquote($cfgRelation['users'])
                 . " WHERE `username`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
         }
 
         if ($cfgRelation['navwork']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['navigationhiding'])
+                . '.' . Util::backquote($cfgRelation['navigationhiding'])
                 . " WHERE `username`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
         }
 
         if ($cfgRelation['savedsearcheswork']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['savedsearches'])
+                . '.' . Util::backquote($cfgRelation['savedsearches'])
                 . " WHERE `username`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
         }
 
         if ($cfgRelation['designersettingswork']) {
-            $remove_query = "DELETE FROM "
+            $remove_query = 'DELETE FROM '
                 . Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['designer_settings'])
+                . '.' . Util::backquote($cfgRelation['designer_settings'])
                 . " WHERE `username`  = '" . $this->dbi->escapeString($username)
                 . "'";
             $this->relation->queryAsControlUser($remove_query);
diff --git a/libraries/classes/Replication.php b/libraries/classes/Replication.php
index eab03f477e..7624530c93 100644
--- a/libraries/classes/Replication.php
+++ b/libraries/classes/Replication.php
@@ -35,7 +35,7 @@ class Replication
             = empty($mysqlInfo[$mysqlKey])
                 ? []
                 : explode(
-                    ",",
+                    ',',
                     $mysqlInfo[$mysqlKey]
                 );
 
@@ -52,7 +52,7 @@ class Replication
      */
     public function extractDbOrTable($string, $what = 'db')
     {
-        $list = explode(".", $string);
+        $list = explode('.', $string);
         if ('db' == $what) {
             return $list[0];
         } else {
@@ -77,14 +77,14 @@ class Replication
         $action = mb_strtoupper($action);
         $control = mb_strtoupper($control);
 
-        if ($action != "START" && $action != "STOP") {
+        if ($action != 'START' && $action != 'STOP') {
             return -1;
         }
-        if ($control != "SQL_THREAD" && $control != "IO_THREAD" && $control != null) {
+        if ($control != 'SQL_THREAD' && $control != 'IO_THREAD' && $control != null) {
             return -1;
         }
 
-        return $GLOBALS['dbi']->tryQuery($action . " SLAVE " . $control . ";", $link);
+        return $GLOBALS['dbi']->tryQuery($action . ' SLAVE ' . $control . ';', $link);
     }
 
     /**
@@ -113,7 +113,7 @@ class Replication
         $link = null
     ) {
         if ($stop) {
-            $this->slaveControl("STOP", null, $link);
+            $this->slaveControl('STOP', null, $link);
         }
 
         $out = $GLOBALS['dbi']->tryQuery(
@@ -122,13 +122,13 @@ class Replication
             'MASTER_PORT=' . ($port * 1) . ',' .
             'MASTER_USER=\'' . $user . '\',' .
             'MASTER_PASSWORD=\'' . $password . '\',' .
-            'MASTER_LOG_FILE=\'' . $pos["File"] . '\',' .
-            'MASTER_LOG_POS=' . $pos["Position"] . ';',
+            'MASTER_LOG_FILE=\'' . $pos['File'] . '\',' .
+            'MASTER_LOG_POS=' . $pos['Position'] . ';',
             $link
         );
 
         if ($start) {
-            $this->slaveControl("START", null, $link);
+            $this->slaveControl('START', null, $link);
         }
 
         return $out;
@@ -155,9 +155,9 @@ class Replication
         $server = [];
         $server['user'] = $user;
         $server['password'] = $password;
-        $server["host"] = Core::sanitizeMySQLHost($host);
-        $server["port"] = $port;
-        $server["socket"] = $socket;
+        $server['host'] = Core::sanitizeMySQLHost($host);
+        $server['port'] = $port;
+        $server['socket'] = $socket;
 
         // 5th parameter set to true means that it's an auxiliary connection
         // and we must not go back to login page if it fails
@@ -178,8 +178,8 @@ class Replication
         $output = [];
 
         if (! empty($data)) {
-            $output["File"] = $data[0]["File"];
-            $output["Position"] = $data[0]["Position"];
+            $output['File'] = $data[0]['File'];
+            $output['Position'] = $data[0]['Position'];
         }
         return $output;
     }
diff --git a/libraries/classes/ReplicationGui.php b/libraries/classes/ReplicationGui.php
index c35a000062..00aafbf25a 100644
--- a/libraries/classes/ReplicationGui.php
+++ b/libraries/classes/ReplicationGui.php
@@ -550,9 +550,9 @@ class ReplicationGui
             $_POST['sr_slave_control_parm'] = null;
         }
         if ($_POST['sr_slave_action'] == 'reset') {
-            $qStop = $this->replication->slaveControl("STOP");
-            $qReset = $GLOBALS['dbi']->tryQuery("RESET SLAVE;");
-            $qStart = $this->replication->slaveControl("START");
+            $qStop = $this->replication->slaveControl('STOP');
+            $qReset = $GLOBALS['dbi']->tryQuery('RESET SLAVE;');
+            $qStart = $this->replication->slaveControl('START');
 
             $result = ($qStop !== false && $qStop !== -1 &&
                 $qReset !== false && $qReset !== -1 &&
@@ -581,11 +581,11 @@ class ReplicationGui
             $count = $_POST['sr_skip_errors_count'] * 1;
         }
 
-        $qStop = $this->replication->slaveControl("STOP");
+        $qStop = $this->replication->slaveControl('STOP');
         $qSkip = $GLOBALS['dbi']->tryQuery(
-            "SET GLOBAL SQL_SLAVE_SKIP_COUNTER = " . $count . ";"
+            'SET GLOBAL SQL_SLAVE_SKIP_COUNTER = ' . $count . ';'
         );
-        $qStart = $this->replication->slaveControl("START");
+        $qStart = $this->replication->slaveControl('START');
 
         $result = ($qStop !== false && $qStop !== -1 &&
             $qSkip !== false && $qSkip !== -1 &&
diff --git a/libraries/classes/Rte/Events.php b/libraries/classes/Rte/Events.php
index 18c34c9912..58a7b3b9d1 100644
--- a/libraries/classes/Rte/Events.php
+++ b/libraries/classes/Rte/Events.php
@@ -164,7 +164,7 @@ class Events
                         'EVENT',
                         $_POST['item_original_name']
                     );
-                    $drop_item = "DROP EVENT "
+                    $drop_item = 'DROP EVENT '
                         . Util::backquote($_POST['item_original_name'])
                         . ";\n";
                     $result = $this->dbi->tryQuery($drop_item);
@@ -289,7 +289,7 @@ class Events
                 $item = $this->getDataFromRequest();
                 $mode = 'add';
             } elseif (! empty($_REQUEST['edit_item'])) {
-                $title = __("Edit event");
+                $title = __('Edit event');
                 if (! empty($_REQUEST['item_name'])
                     && empty($_POST['editor_process_edit'])
                     && empty($_POST['item_changetype'])
@@ -354,13 +354,13 @@ class Events
         global $db;
 
         $retval = [];
-        $columns = "`EVENT_NAME`, `STATUS`, `EVENT_TYPE`, `EXECUTE_AT`, "
-                 . "`INTERVAL_VALUE`, `INTERVAL_FIELD`, `STARTS`, `ENDS`, "
-                 . "`EVENT_DEFINITION`, `ON_COMPLETION`, `DEFINER`, `EVENT_COMMENT`";
-        $where   = "EVENT_SCHEMA " . Util::getCollateForIS() . "="
+        $columns = '`EVENT_NAME`, `STATUS`, `EVENT_TYPE`, `EXECUTE_AT`, '
+                 . '`INTERVAL_VALUE`, `INTERVAL_FIELD`, `STARTS`, `ENDS`, '
+                 . '`EVENT_DEFINITION`, `ON_COMPLETION`, `DEFINER`, `EVENT_COMMENT`';
+        $where   = 'EVENT_SCHEMA ' . Util::getCollateForIS() . '='
                  . "'" . $this->dbi->escapeString($db) . "' "
                  . "AND EVENT_NAME='" . $this->dbi->escapeString($name) . "'";
-        $query   = "SELECT $columns FROM `INFORMATION_SCHEMA`.`EVENTS` WHERE $where;";
+        $query   = 'SELECT ' . $columns . ' FROM `INFORMATION_SCHEMA`.`EVENTS` WHERE ' . $where . ';';
         $item    = $this->dbi->fetchSingleRow($query);
         if (! $item) {
             return false;
@@ -429,7 +429,7 @@ class Events
         $original_data = '';
         if ($mode == 'edit') {
             $original_data = "<input name='item_original_name' "
-                           . "type='hidden' value='{$item['item_original_name']}'>\n";
+                           . "type='hidden' value='" . $item['item_original_name'] . "'>\n";
         }
         // Handle some logic first
         if ($operation == 'change') {
@@ -449,54 +449,54 @@ class Events
             $isonetime_class   = ' hide';
         }
         // Create the output
-        $retval  = "";
-        $retval .= "<!-- START " . $modeToUpper . " EVENT FORM -->\n\n";
+        $retval  = '';
+        $retval .= '<!-- START ' . $modeToUpper . " EVENT FORM -->\n\n";
         $retval .= '<form class="rte_form" action="' . Url::getFromRoute('/database/events') . '" method="post">' . "\n";
-        $retval .= "<input name='{$mode}_item' type='hidden' value='1'>\n";
+        $retval .= "<input name='" . $mode . "_item' type='hidden' value='1'>\n";
         $retval .= $original_data;
         $retval .= Url::getHiddenInputs($db, $table) . "\n";
         $retval .= "<fieldset>\n";
-        $retval .= "<legend>" . __('Details') . "</legend>\n";
+        $retval .= '<legend>' . __('Details') . "</legend>\n";
         $retval .= "<table class='rte_table'>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Event name') . "</td>\n";
+        $retval .= '    <td>' . __('Event name') . "</td>\n";
         $retval .= "    <td><input type='text' name='item_name' \n";
-        $retval .= "               value='{$item['item_name']}'\n";
+        $retval .= "               value='" . $item['item_name'] . "'\n";
         $retval .= "               maxlength='64'></td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Status') . "</td>\n";
+        $retval .= '    <td>' . __('Status') . "</td>\n";
         $retval .= "    <td>\n";
         $retval .= "        <select name='item_status'>\n";
         foreach ($event_status['display'] as $key => $value) {
-            $selected = "";
+            $selected = '';
             if (! empty($item['item_status']) && $item['item_status'] == $value) {
                 $selected = " selected='selected'";
             }
-            $retval .= "<option$selected>$value</option>";
+            $retval .= '<option' . $selected . '>' . $value . '</option>';
         }
         $retval .= "        </select>\n";
         $retval .= "    </td>\n";
         $retval .= "</tr>\n";
 
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Event type') . "</td>\n";
+        $retval .= '    <td>' . __('Event type') . "</td>\n";
         $retval .= "    <td>\n";
         if ($response->isAjax()) {
             $retval .= "        <select name='item_type'>";
             foreach ($event_type as $key => $value) {
-                $selected = "";
+                $selected = '';
                 if (! empty($item['item_type']) && $item['item_type'] == $value) {
                     $selected = " selected='selected'";
                 }
-                $retval .= "<option$selected>$value</option>";
+                $retval .= '<option' . $selected . '>' . $value . '</option>';
             }
             $retval .= "        </select>\n";
         } else {
             $retval .= "        <input name='item_type' type='hidden' \n";
-            $retval .= "               value='{$item['item_type']}'>\n";
+            $retval .= "               value='" . $item['item_type'] . "'>\n";
             $retval .= "        <div class='font_weight_bold text-center w-50'>\n";
-            $retval .= "            {$item['item_type']}\n";
+            $retval .= '            ' . $item['item_type'] . "\n";
             $retval .= "        </div>\n";
             $retval .= "        <input type='submit'\n";
             $retval .= "               name='item_changetype' class='w-50'\n";
@@ -506,85 +506,85 @@ class Events
         }
         $retval .= "    </td>\n";
         $retval .= "</tr>\n";
-        $retval .= "<tr class='onetime_event_row $isonetime_class'>\n";
-        $retval .= "    <td>" . __('Execute at') . "</td>\n";
+        $retval .= "<tr class='onetime_event_row " . $isonetime_class . "'>\n";
+        $retval .= '    <td>' . __('Execute at') . "</td>\n";
         $retval .= "    <td class='nowrap'>\n";
         $retval .= "        <input type='text' name='item_execute_at'\n";
-        $retval .= "               value='{$item['item_execute_at']}'\n";
+        $retval .= "               value='" . $item['item_execute_at'] . "'\n";
         $retval .= "               class='datetimefield'>\n";
         $retval .= "    </td>\n";
         $retval .= "</tr>\n";
-        $retval .= "<tr class='recurring_event_row $isrecurring_class'>\n";
-        $retval .= "    <td>" . __('Execute every') . "</td>\n";
+        $retval .= "<tr class='recurring_event_row " . $isrecurring_class . "'>\n";
+        $retval .= '    <td>' . __('Execute every') . "</td>\n";
         $retval .= "    <td>\n";
         $retval .= "        <input class='w-50' type='text'\n";
         $retval .= "               name='item_interval_value'\n";
-        $retval .= "               value='{$item['item_interval_value']}'>\n";
+        $retval .= "               value='" . $item['item_interval_value'] . "'>\n";
         $retval .= "        <select class='w-50' name='item_interval_field'>";
         foreach ($event_interval as $key => $value) {
-            $selected = "";
+            $selected = '';
             if (! empty($item['item_interval_field'])
                 && $item['item_interval_field'] == $value
             ) {
                 $selected = " selected='selected'";
             }
-            $retval .= "<option$selected>$value</option>";
+            $retval .= '<option' . $selected . '>' . $value . '</option>';
         }
         $retval .= "        </select>\n";
         $retval .= "    </td>\n";
         $retval .= "</tr>\n";
-        $retval .= "<tr class='recurring_event_row$isrecurring_class'>\n";
-        $retval .= "    <td>" . _pgettext('Start of recurring event', 'Start');
+        $retval .= "<tr class='recurring_event_row" . $isrecurring_class . "'>\n";
+        $retval .= '    <td>' . _pgettext('Start of recurring event', 'Start');
         $retval .= "    </td>\n";
         $retval .= "    <td class='nowrap'>\n";
         $retval .= "        <input type='text'\n name='item_starts'\n";
-        $retval .= "               value='{$item['item_starts']}'\n";
+        $retval .= "               value='" . $item['item_starts'] . "'\n";
         $retval .= "               class='datetimefield'>\n";
         $retval .= "    </td>\n";
         $retval .= "</tr>\n";
-        $retval .= "<tr class='recurring_event_row$isrecurring_class'>\n";
-        $retval .= "    <td>" . _pgettext('End of recurring event', 'End') . "</td>\n";
+        $retval .= "<tr class='recurring_event_row" . $isrecurring_class . "'>\n";
+        $retval .= '    <td>' . _pgettext('End of recurring event', 'End') . "</td>\n";
         $retval .= "    <td class='nowrap'>\n";
         $retval .= "        <input type='text' name='item_ends'\n";
-        $retval .= "               value='{$item['item_ends']}'\n";
+        $retval .= "               value='" . $item['item_ends'] . "'\n";
         $retval .= "               class='datetimefield'>\n";
         $retval .= "    </td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Definition') . "</td>\n";
+        $retval .= '    <td>' . __('Definition') . "</td>\n";
         $retval .= "    <td><textarea name='item_definition' rows='15' cols='40'>";
         $retval .= $item['item_definition'];
         $retval .= "</textarea></td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('On completion preserve') . "</td>\n";
+        $retval .= '    <td>' . __('On completion preserve') . "</td>\n";
         $retval .= "    <td><input type='checkbox'\n";
-        $retval .= "             name='item_preserve'{$item['item_preserve']}></td>\n";
+        $retval .= "             name='item_preserve'" . $item['item_preserve'] . "></td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Definer') . "</td>\n";
+        $retval .= '    <td>' . __('Definer') . "</td>\n";
         $retval .= "    <td><input type='text' name='item_definer'\n";
-        $retval .= "               value='{$item['item_definer']}'></td>\n";
+        $retval .= "               value='" . $item['item_definer'] . "'></td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Comment') . "</td>\n";
+        $retval .= '    <td>' . __('Comment') . "</td>\n";
         $retval .= "    <td><input type='text' name='item_comment' maxlength='64'\n";
-        $retval .= "               value='{$item['item_comment']}'></td>\n";
+        $retval .= "               value='" . $item['item_comment'] . "'></td>\n";
         $retval .= "</tr>\n";
         $retval .= "</table>\n";
         $retval .= "</fieldset>\n";
         if ($response->isAjax()) {
-            $retval .= "<input type='hidden' name='editor_process_{$mode}'\n";
+            $retval .= "<input type='hidden' name='editor_process_" . $mode . "'\n";
             $retval .= "       value='true'>\n";
             $retval .= "<input type='hidden' name='ajax_request' value='true'>\n";
         } else {
             $retval .= "<fieldset class='tblFooters'>\n";
-            $retval .= "    <input type='submit' name='editor_process_{$mode}'\n";
+            $retval .= "    <input type='submit' name='editor_process_" . $mode . "'\n";
             $retval .= "           value='" . __('Go') . "'>\n";
             $retval .= "</fieldset>\n";
         }
         $retval .= "</form>\n\n";
-        $retval .= "<!-- END " . $modeToUpper . " EVENT FORM -->\n\n";
+        $retval .= '<!-- END ' . $modeToUpper . " EVENT FORM -->\n\n";
 
         return $retval;
     }
diff --git a/libraries/classes/Rte/Export.php b/libraries/classes/Rte/Export.php
index e07aa2613c..3ea0c9c7bb 100644
--- a/libraries/classes/Rte/Export.php
+++ b/libraries/classes/Rte/Export.php
@@ -67,7 +67,7 @@ class Export
                 $export_data = '<textarea cols="40" rows="15" style="width: 100%;">'
                    . $export_data . '</textarea>';
                 echo "<fieldset>\n"
-                   , "<legend>$title</legend>\n"
+                   , '<legend>' . $title . "</legend>\n"
                    , $export_data
                    , "</fieldset>\n";
             }
diff --git a/libraries/classes/Rte/Footer.php b/libraries/classes/Rte/Footer.php
index 965a1b8d22..9fb7bdf6ef 100644
--- a/libraries/classes/Rte/Footer.php
+++ b/libraries/classes/Rte/Footer.php
@@ -65,10 +65,10 @@ class Footer
         }
 
         $icon = mb_strtolower($name) . '_add';
-        $retval  = "";
-        $retval .= "<!-- ADD " . $name . " FORM START -->\n";
+        $retval  = '';
+        $retval .= '<!-- ADD ' . $name . " FORM START -->\n";
         $retval .= "<fieldset class='left'>\n";
-        $retval .= "<legend>" . _pgettext('Create new procedure', 'New') . "</legend>\n";
+        $retval .= '<legend>' . _pgettext('Create new procedure', 'New') . "</legend>\n";
         $retval .= "        <div class='wrap'>\n";
         if (Util::currentUserHasPrivilege($priv, $db, $table)) {
             $retval .= '            <a class="ajax add_anchor" ';
@@ -86,10 +86,10 @@ class Footer
             $retval .= Generator::getIcon($icon);
             $retval .= $this->words->get('add') . "\n";
         }
-        $retval .= "            " . MySQLDocumentation::show($docu) . "\n";
+        $retval .= '            ' . MySQLDocumentation::show($docu) . "\n";
         $retval .= "        </div>\n";
         $retval .= "</fieldset>\n";
-        $retval .= "<!-- ADD " . $name . " FORM END -->\n\n";
+        $retval .= '<!-- ADD ' . $name . " FORM END -->\n\n";
 
         return $retval;
     }
@@ -137,12 +137,12 @@ class Footer
         $options = [
             0 => [
                 'label' => __('OFF'),
-                'value' => "SET GLOBAL event_scheduler=\"OFF\"",
+                'value' => 'SET GLOBAL event_scheduler="OFF"',
                 'selected' => $es_state != 'on',
             ],
             1 => [
                 'label' => __('ON'),
-                'value' => "SET GLOBAL event_scheduler=\"ON\"",
+                'value' => 'SET GLOBAL event_scheduler="ON"',
                 'selected' => $es_state == 'on',
             ],
         ];
@@ -153,7 +153,7 @@ class Footer
         $retval .= $this->getLinks('CREATE_EVENT', 'EVENT', 'EVENT');
         $retval .= "    <fieldset class='right'>\n";
         $retval .= "        <legend>\n";
-        $retval .= "            " . __('Event scheduler status') . "\n";
+        $retval .= '            ' . __('Event scheduler status') . "\n";
         $retval .= "        </legend>\n";
         $retval .= "        <div class='wrap'>\n";
         // show the toggle button
@@ -173,7 +173,7 @@ class Footer
         $retval .= "        </div>\n";
         $retval .= "    </fieldset>\n";
         $retval .= "    <div class='clearfloat'></div>\n";
-        $retval .= "</div>";
+        $retval .= '</div>';
         $retval .= "<!-- FOOTER LINKS END -->\n";
 
         return $retval;
diff --git a/libraries/classes/Rte/General.php b/libraries/classes/Rte/General.php
index d56f904bdb..83ca6a6a8b 100644
--- a/libraries/classes/Rte/General.php
+++ b/libraries/classes/Rte/General.php
@@ -58,7 +58,7 @@ class General
         // this just in case.
         $errors[] = $error . '<br>'
             . __('The backed up query was:')
-            . "\"" . htmlspecialchars($createStatement) . "\"" . '<br>'
+            . '"' . htmlspecialchars($createStatement) . '"' . '<br>'
             . __('MySQL said: ') . $this->dbi->getError();
 
         return $errors;
@@ -93,7 +93,7 @@ class General
                 $response->addJSON('message', $editor);
                 $response->addJSON('title', $title);
             } else {
-                echo "\n\n<h2>$title</h2>\n\n$editor";
+                echo "\n\n<h2>" . $title . "</h2>\n\n" . $editor;
                 unset($_POST);
             }
             exit;
diff --git a/libraries/classes/Rte/Routines.php b/libraries/classes/Rte/Routines.php
index fca54a26f5..8f303fb709 100644
--- a/libraries/classes/Rte/Routines.php
+++ b/libraries/classes/Rte/Routines.php
@@ -194,7 +194,7 @@ class Routines
                 $routine = $this->getDataFromRequest();
                 $mode = 'add';
             } elseif (! empty($_REQUEST['edit_item'])) {
-                $title = __("Edit routine");
+                $title = __('Edit routine');
                 if (! $operation && ! empty($_GET['item_name'])
                     && empty($_POST['editor_process_edit'])
                 ) {
@@ -220,7 +220,7 @@ class Routines
                     $response->addJSON('paramTemplate', $this->getParameterRow());
                     $response->addJSON('type', $routine['item_type']);
                 } else {
-                    echo "\n\n<h2>$title</h2>\n\n$editor";
+                    echo "\n\n<h2>" . $title . "</h2>\n\n" . $editor;
                 }
                 exit;
             } else {
@@ -291,7 +291,7 @@ class Routines
 
                     $privilegesBackup = $this->backupPrivileges();
 
-                    $drop_routine = "DROP {$_POST['item_original_type']} "
+                    $drop_routine = 'DROP ' . $_POST['item_original_type'] . ' '
                         . Util::backquote($_POST['item_original_name'])
                         . ";\n";
                     $result = $this->dbi->tryQuery($drop_routine);
@@ -655,14 +655,14 @@ class Routines
         $retval  = [];
 
         // Build and execute the query
-        $fields  = "SPECIFIC_NAME, ROUTINE_TYPE, DTD_IDENTIFIER, "
-                 . "ROUTINE_DEFINITION, IS_DETERMINISTIC, SQL_DATA_ACCESS, "
-                 . "ROUTINE_COMMENT, SECURITY_TYPE";
-        $where   = "ROUTINE_SCHEMA " . Util::getCollateForIS() . "="
+        $fields  = 'SPECIFIC_NAME, ROUTINE_TYPE, DTD_IDENTIFIER, '
+                 . 'ROUTINE_DEFINITION, IS_DETERMINISTIC, SQL_DATA_ACCESS, '
+                 . 'ROUTINE_COMMENT, SECURITY_TYPE';
+        $where   = 'ROUTINE_SCHEMA ' . Util::getCollateForIS() . '='
                  . "'" . $this->dbi->escapeString($db) . "' "
                  . "AND SPECIFIC_NAME='" . $this->dbi->escapeString($name) . "'"
                  . "AND ROUTINE_TYPE='" . $this->dbi->escapeString($type) . "'";
-        $query   = "SELECT $fields FROM INFORMATION_SCHEMA.ROUTINES WHERE $where;";
+        $query   = 'SELECT ' . $fields . ' FROM INFORMATION_SCHEMA.ROUTINES WHERE ' . $where . ';';
 
         $routine = $this->dbi->fetchSingleRow($query, 'ASSOC');
 
@@ -897,10 +897,10 @@ class Routines
         if ($mode == 'edit') {
             $original_routine = "<input name='item_original_name' "
                               . "type='hidden' "
-                              . "value='{$routine['item_original_name']}'>\n"
+                              . "value='" . $routine['item_original_name'] . "'>\n"
                               . "<input name='item_original_type' "
                               . "type='hidden' "
-                              . "value='{$routine['item_original_type']}'>\n";
+                              . "value='" . $routine['item_original_type'] . "'>\n";
         }
         $isfunction_class   = '';
         $isprocedure_class  = '';
@@ -915,32 +915,32 @@ class Routines
         }
 
         // Create the output
-        $retval  = "";
-        $retval .= "<!-- START " . mb_strtoupper($mode)
+        $retval  = '';
+        $retval .= '<!-- START ' . mb_strtoupper($mode)
             . " ROUTINE FORM -->\n\n";
         $retval .= '<form class="rte_form" action="' . Url::getFromRoute('/database/routines') . '" method="post">' . "\n";
-        $retval .= "<input name='{$mode}_item' type='hidden' value='1'>\n";
+        $retval .= "<input name='" . $mode . "_item' type='hidden' value='1'>\n";
         $retval .= $original_routine;
         $retval .= Url::getHiddenInputs($db) . "\n";
         $retval .= "<fieldset>\n";
-        $retval .= "<legend>" . __('Details') . "</legend>\n";
+        $retval .= '<legend>' . __('Details') . "</legend>\n";
         $retval .= "<table class='rte_table'>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Routine name') . "</td>\n";
+        $retval .= '    <td>' . __('Routine name') . "</td>\n";
         $retval .= "    <td><input type='text' name='item_name' maxlength='64'\n";
-        $retval .= "               value='{$routine['item_name']}'></td>\n";
+        $retval .= "               value='" . $routine['item_name'] . "'></td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Type') . "</td>\n";
+        $retval .= '    <td>' . __('Type') . "</td>\n";
         $retval .= "    <td>\n";
         if ($response->isAjax()) {
             $retval .= "        <select name='item_type'>\n"
-                . "<option value='PROCEDURE'$isprocedure_select>PROCEDURE</option>\n"
-                . "<option value='FUNCTION'$isfunction_select>FUNCTION</option>\n"
+                . "<option value='PROCEDURE'" . $isprocedure_select . ">PROCEDURE</option>\n"
+                . "<option value='FUNCTION'" . $isfunction_select . ">FUNCTION</option>\n"
                 . "</select>\n";
         } else {
             $retval .= "<input name='item_type' type='hidden'"
-                . " value='{$routine['item_type']}'>\n"
+                . " value='" . $routine['item_type'] . "'>\n"
                 . "<div class='font_weight_bold text-center w-50'>\n"
                 . $routine['item_type'] . "\n"
                 . "</div>\n"
@@ -951,58 +951,58 @@ class Routines
         $retval .= "    </td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Parameters') . "</td>\n";
+        $retval .= '    <td>' . __('Parameters') . "</td>\n";
         $retval .= "    <td>\n";
         // parameter handling start
         $retval .= "        <table class='routine_params_table'>\n";
         $retval .= "        <thead>\n";
         $retval .= "        <tr>\n";
         $retval .= "            <td></td>\n";
-        $retval .= "            <th class='routine_direction_cell$isprocedure_class'>"
+        $retval .= "            <th class='routine_direction_cell" . $isprocedure_class . "'>"
             . __('Direction') . "</th>\n";
-        $retval .= "            <th>" . __('Name') . "</th>\n";
-        $retval .= "            <th>" . __('Type') . "</th>\n";
-        $retval .= "            <th>" . __('Length/Values') . "</th>\n";
+        $retval .= '            <th>' . __('Name') . "</th>\n";
+        $retval .= '            <th>' . __('Type') . "</th>\n";
+        $retval .= '            <th>' . __('Length/Values') . "</th>\n";
         $retval .= "            <th colspan='2'>" . __('Options') . "</th>\n";
         $retval .= "            <th class='routine_param_remove hide'>&nbsp;</th>\n";
-        $retval .= "        </tr>";
+        $retval .= '        </tr>';
         $retval .= "        </thead>\n";
         $retval .= "        <tbody>\n";
         for ($i = 0; $i < $routine['item_num_params']; $i++) { // each parameter
             $retval .= $this->getParameterRow($routine, $i, $isprocedure_class);
         }
         $retval .= "        </tbody>\n";
-        $retval .= "        </table>";
-        $retval .= "    </td>";
-        $retval .= "</tr>";
-        $retval .= "<tr>";
-        $retval .= "    <td>&nbsp;</td>";
-        $retval .= "    <td>";
+        $retval .= '        </table>';
+        $retval .= '    </td>';
+        $retval .= '</tr>';
+        $retval .= '<tr>';
+        $retval .= '    <td>&nbsp;</td>';
+        $retval .= '    <td>';
         $retval .= "        <input type='button'";
         $retval .= "               name='routine_addparameter'";
         $retval .= "               value='" . __('Add parameter') . "'>";
-        $retval .= "        <input " . $disableRemoveParam . "";
+        $retval .= '        <input ' . $disableRemoveParam . '';
         $retval .= "               type='submit' ";
         $retval .= "               name='routine_removeparameter'";
         $retval .= "               value='" . __('Remove last parameter') . "'>";
-        $retval .= "    </td>";
-        $retval .= "</tr>";
+        $retval .= '    </td>';
+        $retval .= '</tr>';
         // parameter handling end
         $retval .= "<tr class='routine_return_row" . $isfunction_class . "'>";
-        $retval .= "    <td>" . __('Return type') . "</td>";
+        $retval .= '    <td>' . __('Return type') . '</td>';
         $retval .= "    <td><select name='item_returntype'>";
         $retval .= Util::getSupportedDatatypes(true, $routine['item_returntype']);
-        $retval .= "    </select></td>";
-        $retval .= "</tr>";
+        $retval .= '    </select></td>';
+        $retval .= '</tr>';
         $retval .= "<tr class='routine_return_row" . $isfunction_class . "'>";
-        $retval .= "    <td>" . __('Return length/values') . "</td>";
+        $retval .= '    <td>' . __('Return length/values') . '</td>';
         $retval .= "    <td><input type='text' name='item_returnlength'";
         $retval .= "        value='" . $routine['item_returnlength'] . "'></td>";
         $retval .= "    <td class='hide no_len'>---</td>";
-        $retval .= "</tr>";
+        $retval .= '</tr>';
         $retval .= "<tr class='routine_return_row" . $isfunction_class . "'>";
-        $retval .= "    <td>" . __('Return options') . "</td>";
-        $retval .= "    <td><div>";
+        $retval .= '    <td>' . __('Return options') . '</td>';
+        $retval .= '    <td><div>';
         $retval .= '<select lang="en" dir="ltr" name="item_returnopts_text">' . "\n";
         $retval .= '<option value="">' . __('Charset') . '</option>' . "\n";
         $retval .= '<option value=""></option>' . "\n";
@@ -1017,40 +1017,40 @@ class Routines
         }
 
         $retval .= '</select>' . "\n";
-        $retval .= "    </div>";
+        $retval .= '    </div>';
         $retval .= "    <div><select name='item_returnopts_num'>";
         $retval .= "        <option value=''></option>";
         foreach ($param_opts_num as $key => $value) {
-            $selected = "";
+            $selected = '';
             if (! empty($routine['item_returnopts_num'])
                 && $routine['item_returnopts_num'] == $value
             ) {
                 $selected = " selected='selected'";
             }
-            $retval .= "<option" . $selected . ">" . $value . "</option>";
+            $retval .= '<option' . $selected . '>' . $value . '</option>';
         }
-        $retval .= "    </select></div>";
+        $retval .= '    </select></div>';
         $retval .= "    <div class='hide no_opts'>---</div>";
-        $retval .= "</td>";
-        $retval .= "</tr>";
-        $retval .= "<tr>";
-        $retval .= "    <td>" . __('Definition') . "</td>";
+        $retval .= '</td>';
+        $retval .= '</tr>';
+        $retval .= '<tr>';
+        $retval .= '    <td>' . __('Definition') . '</td>';
         $retval .= "    <td><textarea name='item_definition' rows='15' cols='40'>";
         $retval .= $routine['item_definition'];
-        $retval .= "</textarea></td>";
-        $retval .= "</tr>";
-        $retval .= "<tr>";
-        $retval .= "    <td>" . __('Is deterministic') . "</td>";
+        $retval .= '</textarea></td>';
+        $retval .= '</tr>';
+        $retval .= '<tr>';
+        $retval .= '    <td>' . __('Is deterministic') . '</td>';
         $retval .= "    <td><input type='checkbox' name='item_isdeterministic'"
-            . $routine['item_isdeterministic'] . "></td>";
-        $retval .= "</tr>";
+            . $routine['item_isdeterministic'] . '></td>';
+        $retval .= '</tr>';
         if (isset($_REQUEST['edit_item'])
             && ! empty($_REQUEST['edit_item'])
         ) {
-            $retval .= "<tr>";
-            $retval .= "    <td>" . __('Adjust privileges');
+            $retval .= '<tr>';
+            $retval .= '    <td>' . __('Adjust privileges');
             $retval .= MySQLDocumentation::showDocumentation('faq', 'faq6-39');
-            $retval .= "</td>";
+            $retval .= '</td>';
             if ($GLOBALS['proc_priv']
                 && $GLOBALS['is_reload_priv']
             ) {
@@ -1059,48 +1059,48 @@ class Routines
             } else {
                 $retval .= "    <td><input type='checkbox' "
                     . "name='item_adjust_privileges' value='1' title='" . __(
-                        "You do not have sufficient privileges to perform this "
-                        . "operation; Please refer to the documentation for more "
-                        . "details"
+                        'You do not have sufficient privileges to perform this '
+                        . 'operation; Please refer to the documentation for more '
+                        . 'details'
                     )
                     . "' disabled></td>";
             }
-            $retval .= "</tr>";
+            $retval .= '</tr>';
         }
 
-        $retval .= "<tr>";
-        $retval .= "    <td>" . __('Definer') . "</td>";
+        $retval .= '<tr>';
+        $retval .= '    <td>' . __('Definer') . '</td>';
         $retval .= "    <td><input type='text' name='item_definer'";
         $retval .= "               value='" . $routine['item_definer'] . "'></td>";
-        $retval .= "</tr>";
-        $retval .= "<tr>";
-        $retval .= "    <td>" . __('Security type') . "</td>";
+        $retval .= '</tr>';
+        $retval .= '<tr>';
+        $retval .= '    <td>' . __('Security type') . '</td>';
         $retval .= "    <td><select name='item_securitytype'>";
         $retval .= "        <option value='DEFINER'"
-            . $routine['item_securitytype_definer'] . ">DEFINER</option>";
+            . $routine['item_securitytype_definer'] . '>DEFINER</option>';
         $retval .= "        <option value='INVOKER'"
-            . $routine['item_securitytype_invoker'] . ">INVOKER</option>";
-        $retval .= "    </select></td>";
-        $retval .= "</tr>";
-        $retval .= "<tr>";
-        $retval .= "    <td>" . __('SQL data access') . "</td>";
+            . $routine['item_securitytype_invoker'] . '>INVOKER</option>';
+        $retval .= '    </select></td>';
+        $retval .= '</tr>';
+        $retval .= '<tr>';
+        $retval .= '    <td>' . __('SQL data access') . '</td>';
         $retval .= "    <td><select name='item_sqldataaccess'>";
         foreach ($param_sqldataaccess as $key => $value) {
-            $selected = "";
+            $selected = '';
             if ($routine['item_sqldataaccess'] == $value) {
                 $selected = " selected='selected'";
             }
-            $retval .= "        <option" . $selected . ">" . $value . "</option>";
+            $retval .= '        <option' . $selected . '>' . $value . '</option>';
         }
-        $retval .= "    </select></td>";
-        $retval .= "</tr>";
-        $retval .= "<tr>";
-        $retval .= "    <td>" . __('Comment') . "</td>";
+        $retval .= '    </select></td>';
+        $retval .= '</tr>';
+        $retval .= '<tr>';
+        $retval .= '    <td>' . __('Comment') . '</td>';
         $retval .= "    <td><input type='text' name='item_comment' maxlength='64'";
         $retval .= "    value='" . $routine['item_comment'] . "'></td>";
-        $retval .= "</tr>";
-        $retval .= "</table>";
-        $retval .= "</fieldset>";
+        $retval .= '</tr>';
+        $retval .= '</table>';
+        $retval .= '</fieldset>';
         if ($response->isAjax()) {
             $retval .= "<input type='hidden' name='editor_process_" . $mode . "'";
             $retval .= "       value='true'>";
@@ -1109,10 +1109,10 @@ class Routines
             $retval .= "<fieldset class='tblFooters'>";
             $retval .= "    <input type='submit' name='editor_process_" . $mode . "'";
             $retval .= "           value='" . __('Go') . "'>";
-            $retval .= "</fieldset>";
+            $retval .= '</fieldset>';
         }
-        $retval .= "</form>";
-        $retval .= "<!-- END " . mb_strtoupper($mode) . " ROUTINE FORM -->";
+        $retval .= '</form>';
+        $retval .= '<!-- END ' . mb_strtoupper($mode) . ' ROUTINE FORM -->';
 
         return $retval;
     }
@@ -1135,16 +1135,16 @@ class Routines
                 $arr = explode('@', $_POST['item_definer']);
 
                 $do_backquote = true;
-                if (substr($arr[0], 0, 1) === "`"
-                    && substr($arr[0], -1) === "`"
+                if (substr($arr[0], 0, 1) === '`'
+                    && substr($arr[0], -1) === '`'
                 ) {
                     $do_backquote = false;
                 }
                 $query .= 'DEFINER=' . Util::backquote($arr[0], $do_backquote);
 
                 $do_backquote = true;
-                if (substr($arr[1], 0, 1) === "`"
-                    && substr($arr[1], -1) === "`"
+                if (substr($arr[1], 0, 1) === '`'
+                    && substr($arr[1], -1) === '`'
                 ) {
                     $do_backquote = false;
                 }
@@ -1191,12 +1191,12 @@ class Routines
                         && ! empty($_POST['item_param_dir'][$i])
                         && in_array($_POST['item_param_dir'][$i], $param_directions)
                     ) {
-                        $params .= $_POST['item_param_dir'][$i] . " "
+                        $params .= $_POST['item_param_dir'][$i] . ' '
                             . Util::backquote($item_param_name[$i])
-                            . " " . $item_param_type[$i];
+                            . ' ' . $item_param_type[$i];
                     } elseif ($_POST['item_type'] == 'FUNCTION') {
                         $params .= Util::backquote($item_param_name[$i])
-                            . " " . $item_param_type[$i];
+                            . ' ' . $item_param_type[$i];
                     } elseif (! $warned_about_dir) {
                         $warned_about_dir = true;
                         $errors[] = sprintf(
@@ -1212,7 +1212,7 @@ class Routines
                             $item_param_type[$i]
                         )
                     ) {
-                        $params .= "(" . $item_param_length[$i] . ")";
+                        $params .= '(' . $item_param_length[$i] . ')';
                     } elseif ($item_param_length[$i] == ''
                         && preg_match(
                             '@^(ENUM|SET|VARCHAR|VARBINARY)$@i',
@@ -1246,7 +1246,7 @@ class Routines
                         }
                     }
                     if ($i != (count($item_param_name) - 1)) {
-                        $params .= ", ";
+                        $params .= ', ';
                     }
                 } else {
                     $errors[] = __(
@@ -1256,7 +1256,7 @@ class Routines
                 }
             }
         }
-        $query .= "(" . $params . ") ";
+        $query .= '(' . $params . ') ';
         if ($_POST['item_type'] == 'FUNCTION') {
             $item_returntype = isset($_POST['item_returntype'])
                 ? $_POST['item_returntype']
@@ -1268,7 +1268,7 @@ class Routines
                     Util::getSupportedDatatypes()
                 )
             ) {
-                $query .= "RETURNS " . $item_returntype;
+                $query .= 'RETURNS ' . $item_returntype;
             } else {
                 $errors[] = __('You must provide a valid return type for the routine.');
             }
@@ -1279,7 +1279,7 @@ class Routines
                     $item_returntype
                 )
             ) {
-                $query .= "(" . $_POST['item_returnlength'] . ")";
+                $query .= '(' . $_POST['item_returnlength'] . ')';
             } elseif (empty($_POST['item_returnlength'])
                 && preg_match(
                     '@^(ENUM|SET|VARCHAR|VARBINARY)$@i',
@@ -1393,40 +1393,40 @@ class Routines
                             $all_functions
                         )
                     ) {
-                        $queries[] = "SET @p$i="
+                        $queries[] = 'SET @p' . $i . '='
                             . $_POST['funcs'][$routine['item_param_name'][$i]]
-                            . "('$value');\n";
+                            . "('" . $value . "');\n";
                     } else {
-                        $queries[] = "SET @p$i='$value';\n";
+                        $queries[] = 'SET @p' . $i . "='" . $value . "';\n";
                     }
-                    $args[] = "@p$i";
+                    $args[] = '@p' . $i;
                 } else {
-                    $args[] = "@p$i";
+                    $args[] = '@p' . $i;
                 }
                 if ($routine['item_type'] == 'PROCEDURE') {
                     if ($routine['item_param_dir'][$i] == 'OUT'
                         || $routine['item_param_dir'][$i] == 'INOUT'
                     ) {
-                        $end_query[] = "@p$i AS "
+                        $end_query[] = '@p' . $i . ' AS '
                             . Util::backquote($routine['item_param_name'][$i]);
                     }
                 }
             }
             if ($routine['item_type'] == 'PROCEDURE') {
-                $queries[] = "CALL " . Util::backquote($routine['item_name'])
-                           . "(" . implode(', ', $args) . ");\n";
+                $queries[] = 'CALL ' . Util::backquote($routine['item_name'])
+                           . '(' . implode(', ', $args) . ");\n";
                 if (count($end_query)) {
-                    $queries[] = "SELECT " . implode(', ', $end_query) . ";\n";
+                    $queries[] = 'SELECT ' . implode(', ', $end_query) . ";\n";
                 }
             } else {
-                $queries[] = "SELECT " . Util::backquote($routine['item_name'])
-                           . "(" . implode(', ', $args) . ") "
-                           . "AS " . Util::backquote($routine['item_name'])
+                $queries[] = 'SELECT ' . Util::backquote($routine['item_name'])
+                           . '(' . implode(', ', $args) . ') '
+                           . 'AS ' . Util::backquote($routine['item_name'])
                             . ";\n";
             }
 
             // Get all the queries as one SQL statement
-            $multiple_query = implode("", $queries);
+            $multiple_query = implode('', $queries);
 
             $outcome = true;
             $affected = 0;
@@ -1444,31 +1444,31 @@ class Routines
                 $output  = Generator::formatSql(implode("\n", $queries));
 
                 // Display results
-                $output .= "<fieldset><legend>";
+                $output .= '<fieldset><legend>';
                 $output .= sprintf(
                     __('Execution results of routine %s'),
                     Util::backquote(htmlspecialchars($routine['item_name']))
                 );
-                $output .= "</legend>";
+                $output .= '</legend>';
 
                 do {
                     $result = $this->dbi->storeResult();
                     $num_rows = $this->dbi->numRows($result);
 
                     if (($result !== false) && ($num_rows > 0)) {
-                        $output .= "<table><tr>";
+                        $output .= '<table><tr>';
                         foreach ($this->dbi->getFieldsMeta($result) as $field) {
-                            $output .= "<th>";
+                            $output .= '<th>';
                             $output .= htmlspecialchars($field->name);
-                            $output .= "</th>";
+                            $output .= '</th>';
                         }
-                        $output .= "</tr>";
+                        $output .= '</tr>';
 
                         while ($row = $this->dbi->fetchAssoc($result)) {
-                            $output .= "<tr>" . $this->browseRow($row) . "</tr>";
+                            $output .= '<tr>' . $this->browseRow($row) . '</tr>';
                         }
 
-                        $output .= "</table>";
+                        $output .= '</table>';
                         $nbResultsetToDisplay++;
                         $affected = $num_rows;
                     }
@@ -1477,14 +1477,14 @@ class Routines
                         break;
                     }
 
-                    $output .= "<br>";
+                    $output .= '<br>';
 
                     $this->dbi->freeResult($result);
                 } while ($outcome = $this->dbi->nextResult());
             }
 
             if ($outcome) {
-                $output .= "</fieldset>";
+                $output .= '</fieldset>';
 
                 $message = __('Your SQL query has been executed successfully.');
                 if ($routine['item_type'] == 'PROCEDURE') {
@@ -1552,14 +1552,14 @@ class Routines
             if ($routine !== false) {
                 $form = $this->getExecuteForm($routine);
                 if ($response->isAjax()) {
-                    $title = __("Execute routine") . " " . Util::backquote(
+                    $title = __('Execute routine') . ' ' . Util::backquote(
                         htmlentities($_GET['item_name'], ENT_QUOTES)
                     );
                     $response->addJSON('message', $form);
                     $response->addJSON('title', $title);
                     $response->addJSON('dialog', true);
                 } else {
-                    echo "\n\n<h2>" . __("Execute routine") . "</h2>\n\n";
+                    echo "\n\n<h2>" . __('Execute routine') . "</h2>\n\n";
                     echo $form;
                 }
                 exit;
@@ -1595,7 +1595,7 @@ class Routines
             } else {
                 $value = htmlspecialchars($value);
             }
-            $output .= "<td>" . $value . "</td>";
+            $output .= '<td>' . $value . '</td>';
         }
         return $output;
     }
@@ -1624,33 +1624,33 @@ class Routines
         }
 
         // Create the output
-        $retval  = "";
+        $retval  = '';
         $retval .= "<!-- START ROUTINE EXECUTE FORM -->\n\n";
         $retval .= '<form action="' . Url::getFromRoute('/database/routines') . '" method="post"' . "\n";
         $retval .= "       class='rte_form ajax' onsubmit='return false'>\n";
         $retval .= "<input type='hidden' name='item_name'\n";
-        $retval .= "       value='{$routine['item_name']}'>\n";
+        $retval .= "       value='" . $routine['item_name'] . "'>\n";
         $retval .= "<input type='hidden' name='item_type'\n";
-        $retval .= "       value='{$routine['item_type']}'>\n";
+        $retval .= "       value='" . $routine['item_type'] . "'>\n";
         $retval .= Url::getHiddenInputs($db) . "\n";
         $retval .= "<fieldset>\n";
         if (! $response->isAjax()) {
-            $retval .= "<legend>{$routine['item_name']}</legend>\n";
+            $retval .= '<legend>' . $routine['item_name'] . "</legend>\n";
             $retval .= "<table class='rte_table'>\n";
             $retval .= "<caption class='tblHeaders'>\n";
             $retval .= __('Routine parameters');
             $retval .= "</caption>\n";
         } else {
-            $retval .= "<legend>" . __('Routine parameters') . "</legend>\n";
+            $retval .= '<legend>' . __('Routine parameters') . "</legend>\n";
             $retval .= "<table class='rte_table'>\n";
         }
         $retval .= "<tr>\n";
-        $retval .= "<th>" . __('Name') . "</th>\n";
-        $retval .= "<th>" . __('Type') . "</th>\n";
+        $retval .= '<th>' . __('Name') . "</th>\n";
+        $retval .= '<th>' . __('Type') . "</th>\n";
         if ($cfg['ShowFunctionFields']) {
-            $retval .= "<th>" . __('Function') . "</th>\n";
+            $retval .= '<th>' . __('Function') . "</th>\n";
         }
-        $retval .= "<th>" . __('Value') . "</th>\n";
+        $retval .= '<th>' . __('Value') . "</th>\n";
         $retval .= "</tr>\n";
         // Get a list of data types that are not yet supported.
         $no_support_types = Util::unsupportedDatatypes();
@@ -1661,8 +1661,8 @@ class Routines
                 continue;
             }
             $retval .= "\n<tr>\n";
-            $retval .= "<td>{$routine['item_param_name'][$i]}</td>\n";
-            $retval .= "<td>{$routine['item_param_type'][$i]}</td>\n";
+            $retval .= '<td>' . $routine['item_param_name'][$i] . "</td>\n";
+            $retval .= '<td>' . $routine['item_param_type'][$i] . "</td>\n";
             if ($cfg['ShowFunctionFields']) {
                 $retval .= "<td>\n";
                 if (false !== stripos($routine['item_param_type'][$i], 'enum')
@@ -1687,7 +1687,7 @@ class Routines
                     $retval .= "<select name='funcs["
                         . $routine['item_param_name'][$i] . "]'>";
                     $retval .= Generator::getFunctionsForField($field, false, []);
-                    $retval .= "</select>";
+                    $retval .= '</select>';
                 }
                 $retval .= "</td>\n";
             }
@@ -1722,7 +1722,7 @@ class Routines
             )) {
                 $retval .= "\n";
             } else {
-                $retval .= "<input class='$class' type='text' name='params["
+                $retval .= "<input class='" . $class . "' type='text' name='params["
                     . $routine['item_param_name'][$i] . "]'>\n";
             }
             $retval .= "</td>\n";
diff --git a/libraries/classes/Rte/RteList.php b/libraries/classes/Rte/RteList.php
index 8e5f691f3f..6d6c6f5b54 100644
--- a/libraries/classes/Rte/RteList.php
+++ b/libraries/classes/Rte/RteList.php
@@ -78,7 +78,7 @@ class RteList
         /**
          * Generate output
          */
-        $retval  = "<!-- LIST OF " . $this->words->get('docu') . " START -->\n";
+        $retval  = '<!-- LIST OF ' . $this->words->get('docu') . " START -->\n";
         $retval .= '<form id="rteListForm" class="ajax" action="';
         switch ($type) {
             case 'routine':
@@ -101,24 +101,24 @@ class RteList
         $retval .= Url::getHiddenInputs($GLOBALS['db'], $GLOBALS['table']);
         $retval .= "<fieldset>\n";
         $retval .= "    <legend>\n";
-        $retval .= "        " . $this->words->get('title') . "\n";
-        $retval .= "        "
+        $retval .= '        ' . $this->words->get('title') . "\n";
+        $retval .= '        '
             . MySQLDocumentation::show($this->words->get('docu')) . "\n";
         $retval .= "    </legend>\n";
-        $retval .= "    <div class='$class1' id='nothing2display'>\n";
-        $retval .= "      " . $this->words->get('nothing') . "\n";
+        $retval .= "    <div class='" . $class1 . "' id='nothing2display'>\n";
+        $retval .= '      ' . $this->words->get('nothing') . "\n";
         $retval .= "    </div>\n";
-        $retval .= "    <table class='data$class2'>\n";
+        $retval .= "    <table class='data" . $class2 . "'>\n";
         $retval .= "        <!-- TABLE HEADERS -->\n";
         $retval .= "        <tr>\n";
         // th cells with a colspan need corresponding td cells, according to W3C
         switch ($type) {
             case 'routine':
                 $retval .= "            <th></th>\n";
-                $retval .= "            <th>" . __('Name') . "</th>\n";
+                $retval .= '            <th>' . __('Name') . "</th>\n";
                 $retval .= "            <th colspan='4'>" . __('Action') . "</th>\n";
-                $retval .= "            <th>" . __('Type') . "</th>\n";
-                $retval .= "            <th>" . __('Returns') . "</th>\n";
+                $retval .= '            <th>' . __('Type') . "</th>\n";
+                $retval .= '            <th>' . __('Returns') . "</th>\n";
                 $retval .= "        </tr>\n";
                 $retval .= "        <tr class='hide'>\n"; // see comment above
                 for ($i = 0; $i < 7; $i++) {
@@ -127,13 +127,13 @@ class RteList
                 break;
             case 'trigger':
                 $retval .= "            <th></th>\n";
-                $retval .= "            <th>" . __('Name') . "</th>\n";
+                $retval .= '            <th>' . __('Name') . "</th>\n";
                 if (empty($table)) {
-                    $retval .= "            <th>" . __('Table') . "</th>\n";
+                    $retval .= '            <th>' . __('Table') . "</th>\n";
                 }
                 $retval .= "            <th colspan='3'>" . __('Action') . "</th>\n";
-                $retval .= "            <th>" . __('Time') . "</th>\n";
-                $retval .= "            <th>" . __('Event') . "</th>\n";
+                $retval .= '            <th>' . __('Time') . "</th>\n";
+                $retval .= '            <th>' . __('Event') . "</th>\n";
                 $retval .= "        </tr>\n";
                 $retval .= "        <tr class='hide'>\n"; // see comment above
                 for ($i = 0; $i < (empty($table) ? 7 : 6); $i++) {
@@ -142,10 +142,10 @@ class RteList
                 break;
             case 'event':
                 $retval .= "            <th></th>\n";
-                $retval .= "            <th>" . __('Name') . "</th>\n";
-                $retval .= "            <th>" . __('Status') . "</th>\n";
+                $retval .= '            <th>' . __('Name') . "</th>\n";
+                $retval .= '            <th>' . __('Status') . "</th>\n";
                 $retval .= "            <th colspan='3'>" . __('Action') . "</th>\n";
-                $retval .= "            <th>" . __('Type') . "</th>\n";
+                $retval .= '            <th>' . __('Type') . "</th>\n";
                 $retval .= "        </tr>\n";
                 $retval .= "        <tr class='hide'>\n"; // see comment above
                 for ($i = 0; $i < 6; $i++) {
@@ -207,7 +207,7 @@ class RteList
 
         $retval .= "</fieldset>\n";
         $retval .= "</form>\n";
-        $retval .= "<!-- LIST OF " . $this->words->get('docu') . " END -->\n";
+        $retval .= '<!-- LIST OF ' . $this->words->get('docu') . " END -->\n";
 
         return $retval;
     }
@@ -230,7 +230,7 @@ class RteList
             Util::backquote($routine['name'])
         );
 
-        $retval  = "        <tr class='$rowclass'>\n";
+        $retval  = "        <tr class='" . $rowclass . "'>\n";
         $retval .= "            <td>\n";
         $retval .= '                <input type="checkbox"'
             . ' class="checkall" name="item_name[]"'
@@ -240,7 +240,7 @@ class RteList
         $retval .= "                <span class='drop_sql hide'>"
             . htmlspecialchars($sql_drop) . "</span>\n";
         $retval .= "                <strong>\n";
-        $retval .= "                    "
+        $retval .= '                    '
             . htmlspecialchars($routine['name']) . "\n";
         $retval .= "                </strong>\n";
         $retval .= "            </td>\n";
@@ -248,11 +248,11 @@ class RteList
 
         // this is for our purpose to decide whether to
         // show the edit link or not, so we need the DEFINER for the routine
-        $where = "ROUTINE_SCHEMA " . Util::getCollateForIS() . "="
+        $where = 'ROUTINE_SCHEMA ' . Util::getCollateForIS() . '='
             . "'" . $this->dbi->escapeString($db) . "' "
             . "AND SPECIFIC_NAME='" . $this->dbi->escapeString($routine['name']) . "'"
             . "AND ROUTINE_TYPE='" . $this->dbi->escapeString($routine['type']) . "'";
-        $query = "SELECT `DEFINER` FROM INFORMATION_SCHEMA.ROUTINES WHERE $where;";
+        $query = 'SELECT `DEFINER` FROM INFORMATION_SCHEMA.ROUTINES WHERE ' . $where . ';';
         $routine_definer = $this->dbi->fetchValue($query);
 
         $curr_user = $this->dbi->getCurrentUser();
@@ -272,7 +272,7 @@ class RteList
                     'item_type' => $routine['type'],
                 ]) . '">' . $titles['Edit'] . "</a>\n";
         } else {
-            $retval .= "                {$titles['NoEdit']}\n";
+            $retval .= '                ' . $titles['NoEdit'] . "\n";
         }
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
@@ -330,7 +330,7 @@ class RteList
                     )
                     . '">' . $titles['Execute'] . "</a>\n";
             } else {
-                $retval .= "                {$titles['NoExecute']}\n";
+                $retval .= '                ' . $titles['NoExecute'] . "\n";
             }
         }
 
@@ -349,7 +349,7 @@ class RteList
                     'item_type' => $routine['type'],
                 ]) . '">' . $titles['Export'] . "</a>\n";
         } else {
-            $retval .= "                {$titles['NoExport']}\n";
+            $retval .= '                ' . $titles['NoExport'] . "\n";
         }
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
@@ -368,10 +368,10 @@ class RteList
         );
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
-        $retval .= "                 {$routine['type']}\n";
+        $retval .= '                 ' . $routine['type'] . "\n";
         $retval .= "            </td>\n";
         $retval .= "            <td dir=\"ltr\">\n";
-        $retval .= "                "
+        $retval .= '                '
             . htmlspecialchars($routine['returns']) . "\n";
         $retval .= "            </td>\n";
         $retval .= "        </tr>\n";
@@ -391,7 +391,7 @@ class RteList
     {
         global $db, $table, $titles;
 
-        $retval  = "        <tr class='$rowclass'>\n";
+        $retval  = "        <tr class='" . $rowclass . "'>\n";
         $retval .= "            <td>\n";
         $retval .= '                <input type="checkbox"'
             . ' class="checkall" name="item_name[]"'
@@ -401,7 +401,7 @@ class RteList
         $retval .= "                <span class='drop_sql hide'>"
             . htmlspecialchars($trigger['drop']) . "</span>\n";
         $retval .= "                <strong>\n";
-        $retval .= "                    " . htmlspecialchars($trigger['name']) . "\n";
+        $retval .= '                    ' . htmlspecialchars($trigger['name']) . "\n";
         $retval .= "                </strong>\n";
         $retval .= "            </td>\n";
         if (empty($table)) {
@@ -411,7 +411,7 @@ class RteList
                     'db' => $db,
                     'table' => $trigger['table'],
                 ]) . '">'
-                . htmlspecialchars($trigger['table']) . "</a>";
+                . htmlspecialchars($trigger['table']) . '</a>';
             $retval .= "            </td>\n";
         }
         $retval .= "            <td>\n";
@@ -425,7 +425,7 @@ class RteList
                     'item_name' => $trigger['name'],
                 ]) . '">' . $titles['Edit'] . "</a>\n";
         } else {
-            $retval .= "                {$titles['NoEdit']}\n";
+            $retval .= '                ' . $titles['NoEdit'] . "\n";
         }
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
@@ -454,14 +454,14 @@ class RteList
                 ['class' => 'ajax drop_anchor']
             );
         } else {
-            $retval .= "                {$titles['NoDrop']}\n";
+            $retval .= '                ' . $titles['NoDrop'] . "\n";
         }
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
-        $retval .= "                 {$trigger['action_timing']}\n";
+        $retval .= '                 ' . $trigger['action_timing'] . "\n";
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
-        $retval .= "                 {$trigger['event_manipulation']}\n";
+        $retval .= '                 ' . $trigger['event_manipulation'] . "\n";
         $retval .= "            </td>\n";
         $retval .= "        </tr>\n";
 
@@ -485,7 +485,7 @@ class RteList
             Util::backquote($event['name'])
         );
 
-        $retval  = "        <tr class='$rowclass'>\n";
+        $retval  = "        <tr class='" . $rowclass . "'>\n";
         $retval .= "            <td>\n";
         $retval .= '                <input type="checkbox"'
             . ' class="checkall" name="item_name[]"'
@@ -495,12 +495,12 @@ class RteList
         $retval .= "                <span class='drop_sql hide'>"
             . htmlspecialchars($sql_drop) . "</span>\n";
         $retval .= "                <strong>\n";
-        $retval .= "                    "
+        $retval .= '                    '
             . htmlspecialchars($event['name']) . "\n";
         $retval .= "                </strong>\n";
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
-        $retval .= "                 {$event['status']}\n";
+        $retval .= '                 ' . $event['status'] . "\n";
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
         if (Util::currentUserHasPrivilege('EVENT', $db)) {
@@ -512,7 +512,7 @@ class RteList
                     'item_name' => $event['name'],
                 ]) . '">' . $titles['Edit'] . "</a>\n";
         } else {
-            $retval .= "                {$titles['NoEdit']}\n";
+            $retval .= '                ' . $titles['NoEdit'] . "\n";
         }
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
@@ -540,11 +540,11 @@ class RteList
                 ['class' => 'ajax drop_anchor']
             );
         } else {
-            $retval .= "                {$titles['NoDrop']}\n";
+            $retval .= '                ' . $titles['NoDrop'] . "\n";
         }
         $retval .= "            </td>\n";
         $retval .= "            <td>\n";
-        $retval .= "                 {$event['type']}\n";
+        $retval .= '                 ' . $event['type'] . "\n";
         $retval .= "            </td>\n";
         $retval .= "        </tr>\n";
 
diff --git a/libraries/classes/Rte/Triggers.php b/libraries/classes/Rte/Triggers.php
index c4e17efd9d..969a28bbc1 100644
--- a/libraries/classes/Rte/Triggers.php
+++ b/libraries/classes/Rte/Triggers.php
@@ -268,7 +268,7 @@ class Triggers
                 $item = $this->getDataFromRequest();
                 $mode = 'add';
             } elseif (! empty($_REQUEST['edit_item'])) {
-                $title = __("Edit trigger");
+                $title = __('Edit trigger');
                 if (! empty($_REQUEST['item_name'])
                     && empty($_POST['editor_process_edit'])
                 ) {
@@ -373,40 +373,40 @@ class Triggers
         $original_data = '';
         if ($mode == 'edit') {
             $original_data = "<input name='item_original_name' "
-                           . "type='hidden' value='{$item['item_original_name']}'>\n";
+                           . "type='hidden' value='" . $item['item_original_name'] . "'>\n";
         }
-        $query  = "SELECT `TABLE_NAME` FROM `INFORMATION_SCHEMA`.`TABLES` ";
+        $query  = 'SELECT `TABLE_NAME` FROM `INFORMATION_SCHEMA`.`TABLES` ';
         $query .= "WHERE `TABLE_SCHEMA`='" . $this->dbi->escapeString($db) . "' ";
         $query .= "AND `TABLE_TYPE` IN ('BASE TABLE', 'SYSTEM VERSIONED')";
         $tables = $this->dbi->fetchResult($query);
 
         // Create the output
-        $retval  = "";
-        $retval .= "<!-- START " . $modeToUpper . " TRIGGER FORM -->\n\n";
+        $retval  = '';
+        $retval .= '<!-- START ' . $modeToUpper . " TRIGGER FORM -->\n\n";
         $retval .= '<form class="rte_form" action="' . Url::getFromRoute('/database/triggers') . '" method="post">' . "\n";
-        $retval .= "<input name='{$mode}_item' type='hidden' value='1'>\n";
+        $retval .= "<input name='" . $mode . "_item' type='hidden' value='1'>\n";
         $retval .= $original_data;
         $retval .= Url::getHiddenInputs($db, $table) . "\n";
         $retval .= "<fieldset>\n";
-        $retval .= "<legend>" . __('Details') . "</legend>\n";
+        $retval .= '<legend>' . __('Details') . "</legend>\n";
         $retval .= "<table class='rte_table'>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Trigger name') . "</td>\n";
+        $retval .= '    <td>' . __('Trigger name') . "</td>\n";
         $retval .= "    <td><input type='text' name='item_name' maxlength='64'\n";
-        $retval .= "               value='{$item['item_name']}'></td>\n";
+        $retval .= "               value='" . $item['item_name'] . "'></td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Table') . "</td>\n";
+        $retval .= '    <td>' . __('Table') . "</td>\n";
         $retval .= "    <td>\n";
         $retval .= "        <select name='item_table'>\n";
         foreach ($tables as $key => $value) {
-            $selected = "";
+            $selected = '';
             if ($mode == 'add' && $value == $table) {
                 $selected = " selected='selected'";
             } elseif ($mode == 'edit' && $value == $item['item_table']) {
                 $selected = " selected='selected'";
             }
-            $retval .= "<option$selected>";
+            $retval .= '<option' . $selected . '>';
             $retval .= htmlspecialchars($value);
             $retval .= "</option>\n";
         }
@@ -414,58 +414,58 @@ class Triggers
         $retval .= "    </td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . _pgettext('Trigger action time', 'Time') . "</td>\n";
+        $retval .= '    <td>' . _pgettext('Trigger action time', 'Time') . "</td>\n";
         $retval .= "    <td><select name='item_timing'>\n";
         foreach ($action_timings as $key => $value) {
-            $selected = "";
+            $selected = '';
             if (! empty($item['item_action_timing'])
                 && $item['item_action_timing'] == $value
             ) {
                 $selected = " selected='selected'";
             }
-            $retval .= "<option$selected>$value</option>";
+            $retval .= '<option' . $selected . '>' . $value . '</option>';
         }
         $retval .= "    </select></td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Event') . "</td>\n";
+        $retval .= '    <td>' . __('Event') . "</td>\n";
         $retval .= "    <td><select name='item_event'>\n";
         foreach ($event_manipulations as $key => $value) {
-            $selected = "";
+            $selected = '';
             if (! empty($item['item_event_manipulation'])
                 && $item['item_event_manipulation'] == $value
             ) {
                 $selected = " selected='selected'";
             }
-            $retval .= "<option$selected>$value</option>";
+            $retval .= '<option' . $selected . '>' . $value . '</option>';
         }
         $retval .= "    </select></td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Definition') . "</td>\n";
+        $retval .= '    <td>' . __('Definition') . "</td>\n";
         $retval .= "    <td><textarea name='item_definition' rows='15' cols='40'>";
         $retval .= $item['item_definition'];
         $retval .= "</textarea></td>\n";
         $retval .= "</tr>\n";
         $retval .= "<tr>\n";
-        $retval .= "    <td>" . __('Definer') . "</td>\n";
+        $retval .= '    <td>' . __('Definer') . "</td>\n";
         $retval .= "    <td><input type='text' name='item_definer'\n";
-        $retval .= "               value='{$item['item_definer']}'></td>\n";
+        $retval .= "               value='" . $item['item_definer'] . "'></td>\n";
         $retval .= "</tr>\n";
         $retval .= "</table>\n";
         $retval .= "</fieldset>\n";
         if ($response->isAjax()) {
-            $retval .= "<input type='hidden' name='editor_process_{$mode}'\n";
+            $retval .= "<input type='hidden' name='editor_process_" . $mode . "'\n";
             $retval .= "       value='true'>\n";
             $retval .= "<input type='hidden' name='ajax_request' value='true'>\n";
         } else {
             $retval .= "<fieldset class='tblFooters'>\n";
-            $retval .= "    <input type='submit' name='editor_process_{$mode}'\n";
+            $retval .= "    <input type='submit' name='editor_process_" . $mode . "'\n";
             $retval .= "           value='" . __('Go') . "'>\n";
             $retval .= "</fieldset>\n";
         }
         $retval .= "</form>\n\n";
-        $retval .= "<!-- END " . $modeToUpper . " TRIGGER FORM -->\n\n";
+        $retval .= '<!-- END ' . $modeToUpper . " TRIGGER FORM -->\n\n";
 
         return $retval;
     }
diff --git a/libraries/classes/Sanitize.php b/libraries/classes/Sanitize.php
index 520b35923d..7835e2826a 100644
--- a/libraries/classes/Sanitize.php
+++ b/libraries/classes/Sanitize.php
@@ -330,7 +330,7 @@ class Sanitize
         } elseif (is_array($value)) {
             $result .= '[';
             foreach ($value as $val) {
-                $result .= self::formatJsVal($val) . ",";
+                $result .= self::formatJsVal($val) . ',';
             }
             $result .= "];\n";
         } else {
diff --git a/libraries/classes/SavedSearches.php b/libraries/classes/SavedSearches.php
index b30f53fb72..8f4a2e3da8 100644
--- a/libraries/classes/SavedSearches.php
+++ b/libraries/classes/SavedSearches.php
@@ -285,7 +285,7 @@ class SavedSearches
         }
 
         $savedSearchesTbl
-            = Util::backquote($this->_config['cfgRelation']['db']) . "."
+            = Util::backquote($this->_config['cfgRelation']['db']) . '.'
             . Util::backquote($this->_config['cfgRelation']['savedsearches']);
 
         //If it's an insert.
@@ -307,9 +307,9 @@ class SavedSearches
                 exit;
             }
 
-            $sqlQuery = "INSERT INTO " . $savedSearchesTbl
-                . "(`username`, `db_name`, `search_name`, `search_data`)"
-                . " VALUES ("
+            $sqlQuery = 'INSERT INTO ' . $savedSearchesTbl
+                . '(`username`, `db_name`, `search_name`, `search_data`)'
+                . ' VALUES ('
                 . "'" . $GLOBALS['dbi']->escapeString($this->getUsername()) . "',"
                 . "'" . $GLOBALS['dbi']->escapeString($this->getDbname()) . "',"
                 . "'" . $GLOBALS['dbi']->escapeString($this->getSearchName()) . "',"
@@ -328,7 +328,7 @@ class SavedSearches
 
         //Else, it's an update.
         $wheres = [
-            "id != " . $this->getId(),
+            'id != ' . $this->getId(),
             "search_name = '" . $GLOBALS['dbi']->escapeString($this->getSearchName()) . "'",
         ];
         $existingSearches = $this->getList($wheres);
@@ -344,12 +344,12 @@ class SavedSearches
             exit;
         }
 
-        $sqlQuery = "UPDATE " . $savedSearchesTbl
+        $sqlQuery = 'UPDATE ' . $savedSearchesTbl
             . "SET `search_name` = '"
             . $GLOBALS['dbi']->escapeString($this->getSearchName()) . "', "
             . "`search_data` = '"
             . $GLOBALS['dbi']->escapeString(json_encode($this->getCriterias())) . "' "
-            . "WHERE id = " . $this->getId();
+            . 'WHERE id = ' . $this->getId();
         return (bool) $this->relation->queryAsControlUser($sqlQuery);
     }
 
@@ -372,10 +372,10 @@ class SavedSearches
         }
 
         $savedSearchesTbl
-            = Util::backquote($this->_config['cfgRelation']['db']) . "."
+            = Util::backquote($this->_config['cfgRelation']['db']) . '.'
             . Util::backquote($this->_config['cfgRelation']['savedsearches']);
 
-        $sqlQuery = "DELETE FROM " . $savedSearchesTbl
+        $sqlQuery = 'DELETE FROM ' . $savedSearchesTbl
             . "WHERE id = '" . $GLOBALS['dbi']->escapeString($this->getId()) . "'";
 
         return (bool) $this->relation->queryAsControlUser($sqlQuery);
@@ -400,10 +400,10 @@ class SavedSearches
         }
 
         $savedSearchesTbl = Util::backquote($this->_config['cfgRelation']['db'])
-            . "."
+            . '.'
             . Util::backquote($this->_config['cfgRelation']['savedsearches']);
-        $sqlQuery = "SELECT id, search_name, search_data "
-            . "FROM " . $savedSearchesTbl . " "
+        $sqlQuery = 'SELECT id, search_name, search_data '
+            . 'FROM ' . $savedSearchesTbl . ' '
             . "WHERE id = '" . $GLOBALS['dbi']->escapeString($this->getId()) . "' ";
 
         $resList = $this->relation->queryAsControlUser($sqlQuery);
@@ -439,19 +439,19 @@ class SavedSearches
         }
 
         $savedSearchesTbl = Util::backquote($this->_config['cfgRelation']['db'])
-            . "."
+            . '.'
             . Util::backquote($this->_config['cfgRelation']['savedsearches']);
-        $sqlQuery = "SELECT id, search_name "
-            . "FROM " . $savedSearchesTbl . " "
-            . "WHERE "
+        $sqlQuery = 'SELECT id, search_name '
+            . 'FROM ' . $savedSearchesTbl . ' '
+            . 'WHERE '
             . "username = '" . $GLOBALS['dbi']->escapeString($this->getUsername()) . "' "
             . "AND db_name = '" . $GLOBALS['dbi']->escapeString($this->getDbname()) . "' ";
 
         foreach ($wheres as $where) {
-            $sqlQuery .= "AND " . $where . " ";
+            $sqlQuery .= 'AND ' . $where . ' ';
         }
 
-        $sqlQuery .= "order by search_name ASC ";
+        $sqlQuery .= 'order by search_name ASC ';
 
         $resList = $this->relation->queryAsControlUser($sqlQuery);
 
diff --git a/libraries/classes/Scripts.php b/libraries/classes/Scripts.php
index 16038765fd..7adf0fb02c 100644
--- a/libraries/classes/Scripts.php
+++ b/libraries/classes/Scripts.php
@@ -122,7 +122,7 @@ class Scripts
      */
     public function addCode($code)
     {
-        $this->_code .= "$code\n";
+        $this->_code .= $code . "\n";
     }
 
     /**
@@ -136,7 +136,7 @@ class Scripts
         $retval = [];
         foreach ($this->_files as $file) {
             //If filename contains a "?", continue.
-            if (strpos($file['filename'], "?") !== false) {
+            if (strpos($file['filename'], '?') !== false) {
                 continue;
             }
             $retval[] = [
diff --git a/libraries/classes/Server/Privileges.php b/libraries/classes/Server/Privileges.php
index 5f732ebed0..2af370a216 100644
--- a/libraries/classes/Server/Privileges.php
+++ b/libraries/classes/Server/Privileges.php
@@ -513,18 +513,18 @@ class Privileges
     public function getSqlQueryForDisplayPrivTable($db, $table, $username, $hostname)
     {
         if ($db == '*') {
-            return "SELECT * FROM `mysql`.`user`"
+            return 'SELECT * FROM `mysql`.`user`'
                 . " WHERE `User` = '" . $this->dbi->escapeString($username) . "'"
                 . " AND `Host` = '" . $this->dbi->escapeString($hostname) . "';";
         } elseif ($table == '*') {
-            return "SELECT * FROM `mysql`.`db`"
+            return 'SELECT * FROM `mysql`.`db`'
                 . " WHERE `User` = '" . $this->dbi->escapeString($username) . "'"
                 . " AND `Host` = '" . $this->dbi->escapeString($hostname) . "'"
                 . " AND '" . $this->dbi->escapeString(Util::unescapeMysqlWildcards($db)) . "'"
-                . " LIKE `Db`;";
+                . ' LIKE `Db`;';
         }
-        return "SELECT `Table_priv`"
-            . " FROM `mysql`.`tables_priv`"
+        return 'SELECT `Table_priv`'
+            . ' FROM `mysql`.`tables_priv`'
             . " WHERE `User` = '" . $this->dbi->escapeString($username) . "'"
             . " AND `Host` = '" . $this->dbi->escapeString($hostname) . "'"
             . " AND `Db` = '" . $this->dbi->escapeString(Util::unescapeMysqlWildcards($db)) . "'"
@@ -543,13 +543,13 @@ class Privileges
     {
         $cfgRelation = $this->relation->getRelationsParam();
         $groupTable = Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['usergroups']);
+            . '.' . Util::backquote($cfgRelation['usergroups']);
         $userTable = Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['users']);
+            . '.' . Util::backquote($cfgRelation['users']);
 
         $userGroup = '';
         if (isset($GLOBALS['username'])) {
-            $sql_query = "SELECT `usergroup` FROM " . $userTable
+            $sql_query = 'SELECT `usergroup` FROM ' . $userTable
                 . " WHERE `username` = '" . $this->dbi->escapeString($username) . "'";
             $userGroup = $this->dbi->fetchValue(
                 $sql_query,
@@ -560,7 +560,7 @@ class Privileges
         }
 
         $allUserGroups = ['' => ''];
-        $sql_query = "SELECT DISTINCT `usergroup` FROM " . $groupTable;
+        $sql_query = 'SELECT DISTINCT `usergroup` FROM ' . $groupTable;
         $result = $this->relation->queryAsControlUser($sql_query, false);
         if ($result) {
             while ($row = $this->dbi->fetchRow($result)) {
@@ -593,9 +593,9 @@ class Privileges
         }
 
         $userTable = Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['users']);
+            . '.' . Util::backquote($cfgRelation['users']);
 
-        $sql_query = "SELECT `usergroup` FROM " . $userTable
+        $sql_query = 'SELECT `usergroup` FROM ' . $userTable
             . " WHERE `username` = '" . $this->dbi->escapeString($username) . "'";
         $oldUserGroup = $this->dbi->fetchValue(
             $sql_query,
@@ -605,15 +605,15 @@ class Privileges
         );
 
         if ($oldUserGroup === false) {
-            $upd_query = "INSERT INTO " . $userTable . "(`username`, `usergroup`)"
+            $upd_query = 'INSERT INTO ' . $userTable . '(`username`, `usergroup`)'
                 . " VALUES ('" . $this->dbi->escapeString($username) . "', "
                 . "'" . $this->dbi->escapeString($userGroup) . "')";
         } else {
             if (empty($userGroup)) {
-                $upd_query = "DELETE FROM " . $userTable
+                $upd_query = 'DELETE FROM ' . $userTable
                     . " WHERE `username`='" . $this->dbi->escapeString($username) . "'";
             } elseif ($oldUserGroup != $userGroup) {
-                $upd_query = "UPDATE " . $userTable
+                $upd_query = 'UPDATE ' . $userTable
                     . " SET `usergroup`='" . $this->dbi->escapeString($userGroup) . "'"
                     . " WHERE `username`='" . $this->dbi->escapeString($username) . "'";
             }
@@ -823,8 +823,8 @@ class Privileges
      */
     public function getActiveAuthPlugins()
     {
-        $get_plugins_query = "SELECT `PLUGIN_NAME`, `PLUGIN_DESCRIPTION`"
-            . " FROM `information_schema`.`PLUGINS` "
+        $get_plugins_query = 'SELECT `PLUGIN_NAME`, `PLUGIN_DESCRIPTION`'
+            . ' FROM `information_schema`.`PLUGINS` '
             . "WHERE `PLUGIN_TYPE` = 'AUTHENTICATION';";
         $resultset = $this->dbi->query($get_plugins_query);
 
@@ -1087,7 +1087,7 @@ class Privileges
                     $query_prefix = "ALTER USER '"
                         . $this->dbi->escapeString($username)
                         . "'@'" . $this->dbi->escapeString($hostname) . "'"
-                        . " IDENTIFIED WITH "
+                        . ' IDENTIFIED WITH '
                         . $authentication_plugin
                         . " BY '";
                 } else {
@@ -1137,7 +1137,7 @@ class Privileges
                         : $hashing_function . '(\''
                         . preg_replace('@.@s', '*', $_POST['pma_pw']) . '\')');
 
-                $local_query = "UPDATE `mysql`.`user` SET "
+                $local_query = 'UPDATE `mysql`.`user` SET '
                     . " `authentication_string` = '" . $hashedPassword
                     . "', `Password` = '', "
                     . " `plugin` = '" . $authentication_plugin . "'"
@@ -1150,7 +1150,7 @@ class Privileges
                     'SELECT @@old_passwords;'
                 );
                 $orig_value = $row['@@old_passwords'];
-                $update_plugin_query = "UPDATE `mysql`.`user` SET"
+                $update_plugin_query = 'UPDATE `mysql`.`user` SET'
                     . " `plugin` = '" . $authentication_plugin . "'"
                     . " WHERE `User` = '" . $username . "' AND Host = '"
                     . $hostname . "';";
@@ -1164,7 +1164,7 @@ class Privileges
                         $err_url
                     );
                 }
-                $this->dbi->tryQuery("FLUSH PRIVILEGES;");
+                $this->dbi->tryQuery('FLUSH PRIVILEGES;');
 
                 if ($authentication_plugin == 'mysql_native_password') {
                     // Set the hashing method used by PASSWORD()
@@ -1199,7 +1199,7 @@ class Privileges
                 );
             }
             // Flush privileges after successful password change
-            $this->dbi->tryQuery("FLUSH PRIVILEGES;");
+            $this->dbi->tryQuery('FLUSH PRIVILEGES;');
 
             $message = Message::success(
                 __('The password for %s was changed successfully.')
@@ -1283,16 +1283,16 @@ class Privileges
                         . $this->dbi->escapeString($arr['x509_subject']) . "'";
             }
             if (count($require)) {
-                $require_clause = " REQUIRE " . implode(" AND ", $require);
+                $require_clause = ' REQUIRE ' . implode(' AND ', $require);
             } else {
-                $require_clause = " REQUIRE NONE";
+                $require_clause = ' REQUIRE NONE';
             }
         } elseif (isset($arr['ssl_type']) && $arr['ssl_type'] == 'X509') {
-            $require_clause = " REQUIRE X509";
+            $require_clause = ' REQUIRE X509';
         } elseif (isset($arr['ssl_type']) && $arr['ssl_type'] == 'ANY') {
-            $require_clause = " REQUIRE SSL";
+            $require_clause = ' REQUIRE SSL';
         } else {
-            $require_clause = " REQUIRE NONE";
+            $require_clause = ' REQUIRE NONE';
         }
 
         return $require_clause;
@@ -1826,9 +1826,9 @@ class Privileges
      */
     public function getUserSpecificRights($username, $hostname, $type, $dbname = '')
     {
-        $user_host_condition = " WHERE `User`"
+        $user_host_condition = ' WHERE `User`'
             . " = '" . $this->dbi->escapeString($username) . "'"
-            . " AND `Host`"
+            . ' AND `Host`'
             . " = '" . $this->dbi->escapeString($hostname) . "'";
 
         if ($type == 'database') {
@@ -1905,10 +1905,10 @@ class Privileges
                 . $user_host_condition
                 . ' ORDER BY `Table_name` ASC;';
         } else {
-            $sql_query = "SELECT `Routine_name`, `Proc_priv`"
-                . " FROM `mysql`.`procs_priv`"
+            $sql_query = 'SELECT `Routine_name`, `Proc_priv`'
+                . ' FROM `mysql`.`procs_priv`'
                 . $user_host_condition
-                . " ORDER BY `Routine_name`";
+                . ' ORDER BY `Routine_name`';
         }
 
         $result = $this->dbi->query($sql_query);
@@ -2107,7 +2107,7 @@ class Privileges
             $data['databases'] = $databases;
         } elseif ($type == 'table') {
             $result = @$this->dbi->tryQuery(
-                "SHOW TABLES FROM " . Util::backquote($dbname),
+                'SHOW TABLES FROM ' . Util::backquote($dbname),
                 DatabaseInterface::CONNECT_USER,
                 DatabaseInterface::QUERY_STORE
             );
@@ -2180,7 +2180,7 @@ class Privileges
         foreach ($db_rights as $user) {
             ksort($user);
             foreach ($user as $host) {
-                $check_plugin_query = "SELECT * FROM `mysql`.`user` WHERE "
+                $check_plugin_query = 'SELECT * FROM `mysql`.`user` WHERE '
                     . "`User` = '" . $host['User'] . "' AND `Host` = '"
                     . $host['Host'] . "'";
                 $res = $this->dbi->fetchSingleRow($check_plugin_query);
@@ -2250,7 +2250,7 @@ class Privileges
         // just letters. For letters A-Z, we add the non-used letters
         // as greyed out.
 
-        uksort($array_initials, "strnatcasecmp");
+        uksort($array_initials, 'strnatcasecmp');
 
         return $this->template->render('server/privileges/initials_row', [
             'array_initials' => $array_initials,
@@ -3025,7 +3025,7 @@ class Privileges
         // $sql_query_all is for counting the total no. of users
 
         $sql_query = $sql_query_all = 'SELECT *,' .
-            " IF(`" . $password_column . "` = _latin1 '', 'N', 'Y') AS 'Password'" .
+            ' IF(`' . $password_column . "` = _latin1 '', 'N', 'Y') AS 'Password'" .
             ' FROM `mysql`.`user`';
 
         $sql_query .= (isset($_GET['initial'])
@@ -3832,9 +3832,9 @@ class Privileges
             $password_set_show = null;
         } else {
             if ($password_set_real !== null) {
-                $password_set_real .= ";";
+                $password_set_real .= ';';
             }
-            $password_set_show .= ";";
+            $password_set_show .= ';';
         }
 
         return [
@@ -3883,8 +3883,8 @@ class Privileges
         string $database,
         string $routine
     ): array {
-        $sql = "SELECT `Proc_priv`"
-            . " FROM `mysql`.`procs_priv`"
+        $sql = 'SELECT `Proc_priv`'
+            . ' FROM `mysql`.`procs_priv`'
             . " WHERE `User` = '" . $this->dbi->escapeString($username) . "'"
             . " AND `Host` = '" . $this->dbi->escapeString($hostname) . "'"
             . " AND `Db` = '"
diff --git a/libraries/classes/Server/Status/Monitor.php b/libraries/classes/Server/Status/Monitor.php
index eb6676caa0..38463672f6 100644
--- a/libraries/classes/Server/Status/Monitor.php
+++ b/libraries/classes/Server/Status/Monitor.php
@@ -467,7 +467,7 @@ class Monitor
                 $escapedValue = "'" . $escapedValue . "'";
             }
 
-            if (! preg_match("/[^a-zA-Z0-9_]+/", $name)) {
+            if (! preg_match('/[^a-zA-Z0-9_]+/', $name)) {
                 $this->dbi->query(
                     'SET GLOBAL ' . $name . ' = ' . $escapedValue
                 );
diff --git a/libraries/classes/Server/UserGroups.php b/libraries/classes/Server/UserGroups.php
index b47478d747..b30fe8ffe8 100644
--- a/libraries/classes/Server/UserGroups.php
+++ b/libraries/classes/Server/UserGroups.php
@@ -36,8 +36,8 @@ class UserGroups
 
         $cfgRelation = $relation->getRelationsParam();
         $usersTable = Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['users']);
-        $sql_query = "SELECT `username` FROM " . $usersTable
+            . '.' . Util::backquote($cfgRelation['users']);
+        $sql_query = 'SELECT `username` FROM ' . $usersTable
             . " WHERE `usergroup`='" . $GLOBALS['dbi']->escapeString($userGroup)
             . "'";
         $result = $relation->queryAsControlUser($sql_query, false);
@@ -77,8 +77,8 @@ class UserGroups
         $html_output  = '<div class="row"><h2>' . __('User groups') . '</h2></div>';
         $cfgRelation = $relation->getRelationsParam();
         $groupTable = Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['usergroups']);
-        $sql_query = "SELECT * FROM " . $groupTable . " ORDER BY `usergroup` ASC";
+            . '.' . Util::backquote($cfgRelation['usergroups']);
+        $sql_query = 'SELECT * FROM ' . $groupTable . ' ORDER BY `usergroup` ASC';
         $result = $relation->queryAsControlUser($sql_query, false);
 
         if ($result && $GLOBALS['dbi']->numRows($result)) {
@@ -201,14 +201,14 @@ class UserGroups
         $relation = new Relation($GLOBALS['dbi']);
         $cfgRelation = $relation->getRelationsParam();
         $userTable = Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['users']);
+            . '.' . Util::backquote($cfgRelation['users']);
         $groupTable = Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['usergroups']);
-        $sql_query = "DELETE FROM " . $userTable
+            . '.' . Util::backquote($cfgRelation['usergroups']);
+        $sql_query = 'DELETE FROM ' . $userTable
             . " WHERE `usergroup`='" . $GLOBALS['dbi']->escapeString($userGroup)
             . "'";
         $relation->queryAsControlUser($sql_query, true);
-        $sql_query = "DELETE FROM " . $groupTable
+        $sql_query = 'DELETE FROM ' . $groupTable
             . " WHERE `usergroup`='" . $GLOBALS['dbi']->escapeString($userGroup)
             . "'";
         $relation->queryAsControlUser($sql_query, true);
@@ -266,8 +266,8 @@ class UserGroups
         if ($userGroup != null) {
             $cfgRelation = $relation->getRelationsParam();
             $groupTable = Util::backquote($cfgRelation['db'])
-                . "." . Util::backquote($cfgRelation['usergroups']);
-            $sql_query = "SELECT * FROM " . $groupTable
+                . '.' . Util::backquote($cfgRelation['usergroups']);
+            $sql_query = 'SELECT * FROM ' . $groupTable
                 . " WHERE `usergroup`='" . $GLOBALS['dbi']->escapeString($userGroup)
                 . "'";
             $result = $relation->queryAsControlUser($sql_query, false);
@@ -358,32 +358,32 @@ class UserGroups
         $tabs = Util::getMenuTabList();
         $cfgRelation = $relation->getRelationsParam();
         $groupTable = Util::backquote($cfgRelation['db'])
-            . "." . Util::backquote($cfgRelation['usergroups']);
+            . '.' . Util::backquote($cfgRelation['usergroups']);
 
         if (! $new) {
-            $sql_query = "DELETE FROM " . $groupTable
+            $sql_query = 'DELETE FROM ' . $groupTable
                 . " WHERE `usergroup`='" . $GLOBALS['dbi']->escapeString($userGroup)
                 . "';";
             $relation->queryAsControlUser($sql_query, true);
         }
 
-        $sql_query = "INSERT INTO " . $groupTable
-            . "(`usergroup`, `tab`, `allowed`)"
-            . " VALUES ";
+        $sql_query = 'INSERT INTO ' . $groupTable
+            . '(`usergroup`, `tab`, `allowed`)'
+            . ' VALUES ';
         $first = true;
         foreach ($tabs as $tabGroupName => $tabGroup) {
             foreach ($tabGroup as $tab => $tabName) {
                 if (! $first) {
-                    $sql_query .= ", ";
+                    $sql_query .= ', ';
                 }
                 $tabName = $tabGroupName . '_' . $tab;
                 $allowed = isset($_POST[$tabName]) && $_POST[$tabName] == 'Y';
                 $sql_query .= "('" . $GLOBALS['dbi']->escapeString($userGroup) . "', '" . $tabName . "', '"
-                    . ($allowed ? "Y" : "N") . "')";
+                    . ($allowed ? 'Y' : 'N') . "')";
                 $first = false;
             }
         }
-        $sql_query .= ";";
+        $sql_query .= ';';
         $relation->queryAsControlUser($sql_query, true);
     }
 }
diff --git a/libraries/classes/Setup/ConfigGenerator.php b/libraries/classes/Setup/ConfigGenerator.php
index d0fcbbc1b0..f9289575ee 100644
--- a/libraries/classes/Setup/ConfigGenerator.php
+++ b/libraries/classes/Setup/ConfigGenerator.php
@@ -81,19 +81,19 @@ class ConfigGenerator
     private static function _getVarExport($var_name, $var_value, $crlf)
     {
         if (! is_array($var_value) || empty($var_value)) {
-            return "\$cfg['$var_name'] = "
+            return "\$cfg['" . $var_name . "'] = "
                 . var_export($var_value, true) . ';' . $crlf;
         }
         $ret = '';
         if (self::_isZeroBasedArray($var_value)) {
-            $ret = "\$cfg['$var_name'] = "
+            $ret = "\$cfg['" . $var_name . "'] = "
                 . self::_exportZeroBasedArray($var_value, $crlf)
                 . ';' . $crlf;
         } else {
             // string keys: $cfg[key][subkey] = value
             foreach ($var_value as $k => $v) {
                 $k = preg_replace('/[^A-Za-z0-9_]/', '_', $k);
-                $ret .= "\$cfg['$var_name']['$k'] = "
+                $ret .= "\$cfg['" . $var_name . "']['" . $k . "'] = "
                     . var_export($v, true) . ';' . $crlf;
             }
         }
@@ -131,7 +131,7 @@ class ConfigGenerator
         foreach ($array as $v) {
             $retv[] = var_export($v, true);
         }
-        $ret = "array(";
+        $ret = 'array(';
         if (count($retv) <= 4) {
             // up to 4 values - one line
             $ret .= implode(', ', $retv);
@@ -161,15 +161,15 @@ class ConfigGenerator
             return null;
         }
 
-        $ret = "/* Servers configuration */$crlf\$i = 0;" . $crlf . $crlf;
+        $ret = '/* Servers configuration */' . $crlf . '$i = 0;' . $crlf . $crlf;
         foreach ($servers as $id => $server) {
             $ret .= '/* Server: '
-                . strtr($cf->getServerName($id) . " [$id] ", '*/', '-')
-                . "*/" . $crlf
+                . strtr($cf->getServerName($id) . ' [' . $id . '] ', '*/', '-')
+                . '*/' . $crlf
                 . '$i++;' . $crlf;
             foreach ($server as $k => $v) {
                 $k = preg_replace('/[^A-Za-z0-9_]/', '_', $k);
-                $ret .= "\$cfg['Servers'][\$i]['$k'] = "
+                $ret .= "\$cfg['Servers'][\$i]['" . $k . "'] = "
                     . (is_array($v) && self::_isZeroBasedArray($v)
                         ? self::_exportZeroBasedArray($v, $crlf)
                         : var_export($v, true))
diff --git a/libraries/classes/Sql.php b/libraries/classes/Sql.php
index ba45e8603c..129e12b54b 100644
--- a/libraries/classes/Sql.php
+++ b/libraries/classes/Sql.php
@@ -394,7 +394,7 @@ class Sql
     private function getFullValuesForSetColumn($db, $table, $column, $where_clause)
     {
         $result = $GLOBALS['dbi']->fetchSingleRow(
-            "SELECT `$column` FROM `$db`.`$table` WHERE $where_clause"
+            'SELECT `' . $column . '` FROM `' . $db . '`.`' . $table . '` WHERE ' . $where_clause
         );
 
         return $result[$column];
@@ -434,7 +434,7 @@ class Sql
         $converted_curr_value = htmlentities(
             $curr_value,
             ENT_COMPAT,
-            "UTF-8"
+            'UTF-8'
         );
 
         $selected_values = explode(',', $converted_curr_value);
@@ -789,7 +789,7 @@ class Sql
         $column = $_POST['column'];
         $curr_value = $_POST['curr_value'];
         $response = Response::getInstance();
-        if ($columnType == "enum") {
+        if ($columnType == 'enum') {
             $dropdown = $this->getHtmlForEnumColumnDropdown(
                 $db,
                 $table,
diff --git a/libraries/classes/StorageEngine.php b/libraries/classes/StorageEngine.php
index 49e4f99a4f..eba2b8a823 100644
--- a/libraries/classes/StorageEngine.php
+++ b/libraries/classes/StorageEngine.php
@@ -119,7 +119,7 @@ class StorageEngine
                         );
                     }
                 );
-                foreach (explode(",", $disabled) as $engine) {
+                foreach (explode(',', $disabled) as $engine) {
                     if (isset($storage_engines[$engine])) {
                         $storage_engines[$engine]['Support'] = 'DISABLED';
                     }
@@ -232,7 +232,7 @@ class StorageEngine
      */
     public static function isValid($engine)
     {
-        if ($engine == "PBMS") {
+        if ($engine == 'PBMS') {
             return true;
         }
         $storage_engines = self::getStorageEngines();
diff --git a/libraries/classes/SysInfoLinux.php b/libraries/classes/SysInfoLinux.php
index 64141cc757..3f7f49531f 100644
--- a/libraries/classes/SysInfoLinux.php
+++ b/libraries/classes/SysInfoLinux.php
@@ -29,7 +29,7 @@ class SysInfoLinux extends SysInfoBase
     {
         $buf = file_get_contents('/proc/stat');
         $nums = preg_split(
-            "/\s+/",
+            '/\s+/',
             mb_substr(
                 $buf,
                 0,
diff --git a/libraries/classes/SysInfoWINNT.php b/libraries/classes/SysInfoWINNT.php
index 08be66ae46..dc474f0522 100644
--- a/libraries/classes/SysInfoWINNT.php
+++ b/libraries/classes/SysInfoWINNT.php
@@ -106,7 +106,7 @@ class SysInfoWINNT extends SysInfoBase
     public function memory()
     {
         $buffer = $this->_getWMI(
-            "Win32_OperatingSystem",
+            'Win32_OperatingSystem',
             [
                 'TotalVisibleMemorySize',
                 'FreePhysicalMemory',
diff --git a/libraries/classes/SystemDatabase.php b/libraries/classes/SystemDatabase.php
index 754e8fd1ef..bfe93ecc65 100644
--- a/libraries/classes/SystemDatabase.php
+++ b/libraries/classes/SystemDatabase.php
@@ -86,10 +86,10 @@ class SystemDatabase
 
         // Need to store new transformation details for VIEW
         $new_transformations_sql = sprintf(
-            "INSERT INTO %s.%s ("
-            . "`db_name`, `table_name`, `column_name`, "
-            . "`comment`, `mimetype`, `transformation`, "
-            . "`transformation_options`) VALUES",
+            'INSERT INTO %s.%s ('
+            . '`db_name`, `table_name`, `column_name`, '
+            . '`comment`, `mimetype`, `transformation`, '
+            . '`transformation_options`) VALUES',
             Util::backquote($cfgRelation['db']),
             Util::backquote($cfgRelation['column_info'])
         );
diff --git a/libraries/classes/Table.php b/libraries/classes/Table.php
index 1c076d1fc6..dc72d62f85 100644
--- a/libraries/classes/Table.php
+++ b/libraries/classes/Table.php
@@ -526,7 +526,7 @@ class Table
             $query .= ' ' . $attribute;
 
             if ($is_timestamp
-                && false !== stripos($attribute, "TIMESTAMP")
+                && false !== stripos($attribute, 'TIMESTAMP')
                 && strlen($length) !== 0
                 && $length !== 0
             ) {
@@ -1038,8 +1038,8 @@ class Table
              * @var ExportSql $export_sql_plugin
              */
             $export_sql_plugin = Plugins::getPlugin(
-                "export",
-                "sql",
+                'export',
+                'sql',
                 'libraries/classes/Plugins/Export/',
                 [
                     'export_type' => 'table',
@@ -1086,7 +1086,7 @@ class Table
             // queries.
             // One of the options that alters the behaviour is `ANSI_QUOTES`.
             Context::setMode(
-                $dbi->fetchValue("SELECT @@sql_mode")
+                $dbi->fetchValue('SELECT @@sql_mode')
             );
 
             // -----------------------------------------------------------------
@@ -1816,11 +1816,11 @@ class Table
     protected function getUiPrefsFromDb()
     {
         $cfgRelation = $this->relation->getRelationsParam();
-        $pma_table = Util::backquote($cfgRelation['db']) . "."
+        $pma_table = Util::backquote($cfgRelation['db']) . '.'
             . Util::backquote($cfgRelation['table_uiprefs']);
 
         // Read from phpMyAdmin database
-        $sql_query = " SELECT `prefs` FROM " . $pma_table
+        $sql_query = ' SELECT `prefs` FROM ' . $pma_table
             . " WHERE `username` = '" . $this->_dbi->escapeString($GLOBALS['cfg']['Server']['user']) . "'"
             . " AND `db_name` = '" . $this->_dbi->escapeString($this->_db_name) . "'"
             . " AND `table_name` = '" . $this->_dbi->escapeString($this->_name) . "'";
@@ -1841,13 +1841,13 @@ class Table
     protected function saveUiPrefsToDb()
     {
         $cfgRelation = $this->relation->getRelationsParam();
-        $pma_table = Util::backquote($cfgRelation['db']) . "."
+        $pma_table = Util::backquote($cfgRelation['db']) . '.'
             . Util::backquote($cfgRelation['table_uiprefs']);
 
         $secureDbName = $this->_dbi->escapeString($this->_db_name);
 
         $username = $GLOBALS['cfg']['Server']['user'];
-        $sql_query = " REPLACE INTO " . $pma_table
+        $sql_query = ' REPLACE INTO ' . $pma_table
             . " (username, db_name, table_name, prefs) VALUES ('"
             . $this->_dbi->escapeString($username) . "', '" . $secureDbName
             . "', '" . $this->_dbi->escapeString($this->_name) . "', '"
diff --git a/libraries/classes/Tracker.php b/libraries/classes/Tracker.php
index dec6e11048..f33f6c5b9f 100644
--- a/libraries/classes/Tracker.php
+++ b/libraries/classes/Tracker.php
@@ -143,10 +143,10 @@ class Tracker
             return false;
         }
 
-        $sql_query = " SELECT tracking_active FROM " . self::_getTrackingTable() .
+        $sql_query = ' SELECT tracking_active FROM ' . self::_getTrackingTable() .
         " WHERE db_name = '" . $GLOBALS['dbi']->escapeString($dbname) . "' " .
         " AND table_name = '" . $GLOBALS['dbi']->escapeString($tablename) . "' " .
-        " ORDER BY version DESC LIMIT 1";
+        ' ORDER BY version DESC LIMIT 1';
 
         $result = $GLOBALS['dbi']->fetchValue($sql_query, 0, 0, DatabaseInterface::CONNECT_CONTROL) == 1;
 
@@ -165,7 +165,7 @@ class Tracker
         $date = Util::date('Y-m-d H:i:s');
         $user = preg_replace('/\s+/', ' ', $GLOBALS['cfg']['Server']['user']);
 
-        return "# log " . $date . " " . $user . "\n";
+        return '# log ' . $date . ' ' . $user . "\n";
     }
 
     /**
@@ -203,8 +203,8 @@ class Tracker
          * @var ExportSql $export_sql_plugin
          */
         $export_sql_plugin = Plugins::getPlugin(
-            "export",
-            "sql",
+            'export',
+            'sql',
             'libraries/classes/Plugins/Export/',
             [
                 'export_type' => $export_type,
@@ -237,7 +237,7 @@ class Tracker
         // Get DROP TABLE / DROP VIEW and CREATE TABLE SQL statements
         $sql_backquotes = true;
 
-        $create_sql  = "";
+        $create_sql  = '';
 
         if ($GLOBALS['cfg']['Server']['tracking_add_drop_table'] == true
             && $is_view === false
@@ -254,22 +254,22 @@ class Tracker
         }
 
         $create_sql .= self::getLogComment() .
-            $export_sql_plugin->getTableDef($dbname, $tablename, "\n", "");
+            $export_sql_plugin->getTableDef($dbname, $tablename, "\n", '');
 
         // Save version
 
         $sql_query = "/*NOTRACK*/\n" .
-        "INSERT INTO " . self::_getTrackingTable() . " (" .
-        "db_name, " .
-        "table_name, " .
-        "version, " .
-        "date_created, " .
-        "date_updated, " .
-        "schema_snapshot, " .
-        "schema_sql, " .
-        "data_sql, " .
-        "tracking " .
-        ") " .
+        'INSERT INTO ' . self::_getTrackingTable() . ' (' .
+        'db_name, ' .
+        'table_name, ' .
+        'version, ' .
+        'date_created, ' .
+        'date_updated, ' .
+        'schema_snapshot, ' .
+        'schema_sql, ' .
+        'data_sql, ' .
+        'tracking ' .
+        ') ' .
         "values (
         '" . $GLOBALS['dbi']->escapeString($dbname) . "',
         '" . $GLOBALS['dbi']->escapeString($tablename) . "',
@@ -309,7 +309,7 @@ class Tracker
         $relation = new Relation($GLOBALS['dbi']);
 
         $sql_query = "/*NOTRACK*/\n"
-            . "DELETE FROM " . self::_getTrackingTable()
+            . 'DELETE FROM ' . self::_getTrackingTable()
             . " WHERE `db_name` = '"
             . $GLOBALS['dbi']->escapeString($dbname) . "'"
             . " AND `table_name` = '"
@@ -349,7 +349,7 @@ class Tracker
                 = $GLOBALS['cfg']['Server']['tracking_default_statements'];
         }
 
-        $create_sql  = "";
+        $create_sql  = '';
 
         if ($GLOBALS['cfg']['Server']['tracking_add_drop_database'] == true) {
             $create_sql .= self::getLogComment()
@@ -360,17 +360,17 @@ class Tracker
 
         // Save version
         $sql_query = "/*NOTRACK*/\n" .
-        "INSERT INTO " . self::_getTrackingTable() . " (" .
-        "db_name, " .
-        "table_name, " .
-        "version, " .
-        "date_created, " .
-        "date_updated, " .
-        "schema_snapshot, " .
-        "schema_sql, " .
-        "data_sql, " .
-        "tracking " .
-        ") " .
+        'INSERT INTO ' . self::_getTrackingTable() . ' (' .
+        'db_name, ' .
+        'table_name, ' .
+        'version, ' .
+        'date_created, ' .
+        'date_updated, ' .
+        'schema_snapshot, ' .
+        'schema_sql, ' .
+        'data_sql, ' .
+        'tracking ' .
+        ') ' .
         "values (
         '" . $GLOBALS['dbi']->escapeString($dbname) . "',
         '" . $GLOBALS['dbi']->escapeString('') . "',
@@ -408,7 +408,7 @@ class Tracker
     ) {
         $relation = new Relation($GLOBALS['dbi']);
 
-        $sql_query = " UPDATE " . self::_getTrackingTable() .
+        $sql_query = ' UPDATE ' . self::_getTrackingTable() .
         " SET `tracking_active` = '" . $new_state . "' " .
         " WHERE `db_name` = '" . $GLOBALS['dbi']->escapeString($dbname) . "' " .
         " AND `table_name` = '" . $GLOBALS['dbi']->escapeString($tablename) . "' " .
@@ -458,8 +458,8 @@ class Tracker
             $new_data_processed = $new_data;
         }
 
-        $sql_query = " UPDATE " . self::_getTrackingTable() .
-        " SET `" . $save_to . "` = '" . $new_data_processed . "' " .
+        $sql_query = ' UPDATE ' . self::_getTrackingTable() .
+        ' SET `' . $save_to . "` = '" . $new_data_processed . "' " .
         " WHERE `db_name` = '" . $GLOBALS['dbi']->escapeString($dbname) . "' " .
         " AND `table_name` = '" . $GLOBALS['dbi']->escapeString($tablename) . "' " .
         " AND `version` = '" . $GLOBALS['dbi']->escapeString($version) . "' ";
@@ -519,11 +519,11 @@ class Tracker
     {
         $relation = new Relation($GLOBALS['dbi']);
 
-        $sql_query = " SELECT MAX(version) FROM " . self::_getTrackingTable() .
+        $sql_query = ' SELECT MAX(version) FROM ' . self::_getTrackingTable() .
         " WHERE `db_name` = '" . $GLOBALS['dbi']->escapeString($dbname) . "' " .
         " AND `table_name` = '" . $GLOBALS['dbi']->escapeString($tablename) . "' ";
 
-        if ($statement != "") {
+        if ($statement != '') {
             $sql_query .= " AND FIND_IN_SET('"
                 . $statement . "',tracking) > 0" ;
         }
@@ -550,7 +550,7 @@ class Tracker
     {
         $relation = new Relation($GLOBALS['dbi']);
 
-        $sql_query = " SELECT * FROM " . self::_getTrackingTable() .
+        $sql_query = ' SELECT * FROM ' . self::_getTrackingTable() .
             " WHERE `db_name` = '" . $GLOBALS['dbi']->escapeString($dbname) . "' ";
         if (! empty($tablename)) {
             $sql_query .= " AND `table_name` = '"
@@ -817,7 +817,7 @@ class Tracker
         $relation = new Relation($GLOBALS['dbi']);
 
         // If query is marked as untouchable, leave
-        if (mb_strstr($query, "/*NOTRACK*/")) {
+        if (mb_strstr($query, '/*NOTRACK*/')) {
             return;
         }
 
@@ -895,9 +895,9 @@ class Tracker
 
                 // Mark it as untouchable
                 $sql_query = " /*NOTRACK*/\n"
-                    . " UPDATE " . self::_getTrackingTable()
-                    . " SET " . Util::backquote($save_to)
-                    . " = CONCAT( " . Util::backquote($save_to) . ",'\n"
+                    . ' UPDATE ' . self::_getTrackingTable()
+                    . ' SET ' . Util::backquote($save_to)
+                    . ' = CONCAT( ' . Util::backquote($save_to) . ",'\n"
                     . $GLOBALS['dbi']->escapeString($query) . "') ,"
                     . " `date_updated` = '" . $date . "' ";
 
diff --git a/libraries/classes/Tracking.php b/libraries/classes/Tracking.php
index 879c210100..697d2c7f03 100644
--- a/libraries/classes/Tracking.php
+++ b/libraries/classes/Tracking.php
@@ -115,14 +115,14 @@ class Tracking
     {
         $relation = $this->relation;
         $cfgRelation = $relation->getRelationsParam();
-        $sql_query = " SELECT * FROM " .
-            Util::backquote($cfgRelation['db']) . "." .
+        $sql_query = ' SELECT * FROM ' .
+            Util::backquote($cfgRelation['db']) . '.' .
             Util::backquote($cfgRelation['tracking']) .
             " WHERE db_name = '" . $GLOBALS['dbi']->escapeString($GLOBALS['db']) .
             "' " .
             " AND table_name = '" .
             $GLOBALS['dbi']->escapeString($GLOBALS['table']) . "' " .
-            " ORDER BY version DESC ";
+            ' ORDER BY version DESC ';
 
         return $relation->queryAsControlUser($sql_query);
     }
@@ -206,12 +206,12 @@ class Tracking
         $relation = $this->relation;
         $cfgRelation = $relation->getRelationsParam();
 
-        $sql_query = " SELECT DISTINCT db_name, table_name FROM " .
-            Util::backquote($cfgRelation['db']) . "." .
+        $sql_query = ' SELECT DISTINCT db_name, table_name FROM ' .
+            Util::backquote($cfgRelation['db']) . '.' .
             Util::backquote($cfgRelation['tracking']) .
             " WHERE db_name = '" . $GLOBALS['dbi']->escapeString($GLOBALS['db']) .
             "' " .
-            " ORDER BY db_name, table_name";
+            ' ORDER BY db_name, table_name';
 
         return $relation->queryAsControlUser($sql_query);
     }
@@ -490,8 +490,8 @@ class Tracking
 
         $str_export2 = '<input class="btn btn-primary" type="submit" value="' . __('Go') . '">';
 
-        $html .= "<br>" . sprintf(__('Export as %s'), $str_export1)
-            . $str_export2 . "<br>";
+        $html .= '<br>' . sprintf(__('Export as %s'), $str_export1)
+            . $str_export2 . '<br>';
         $html .= '</form>';
         return $html;
     }
@@ -800,13 +800,13 @@ class Tracking
     public function exportAsSqlDump(array $entries)
     {
         $html = '';
-        $new_query = "# "
+        $new_query = '# '
             . __(
                 'You can execute the dump by creating and using a temporary database. '
                 . 'Please ensure that you have the privileges to do so.'
             )
             . "\n"
-            . "# " . __('Comment out these two lines if you do not need them.') . "\n"
+            . '# ' . __('Comment out these two lines if you do not need them.') . "\n"
             . "\n"
             . "CREATE database IF NOT EXISTS pma_temp_db; \n"
             . "USE pma_temp_db; \n"
@@ -863,7 +863,7 @@ class Tracking
 
         // Replace all multiple whitespaces by a single space
         $table = htmlspecialchars(preg_replace('/\s+/', ' ', $_POST['table']));
-        $dump = "# " . sprintf(
+        $dump = '# ' . sprintf(
             __('Tracking report for table `%s`'),
             $table
         )
diff --git a/libraries/classes/Transformations.php b/libraries/classes/Transformations.php
index b3b0d4aa0c..78e3f61f58 100644
--- a/libraries/classes/Transformations.php
+++ b/libraries/classes/Transformations.php
@@ -53,7 +53,7 @@ class Transformations
         $result = [];
 
         if (strlen($option_string) === 0
-            || ! $transform_options = explode(",", $option_string)
+            || ! $transform_options = explode(',', $option_string)
         ) {
             return $result;
         }
@@ -138,7 +138,7 @@ class Transformations
                 if (preg_match('|^[^.].*_.*_.*\.php$|', $file)) {
                     // File contains transformation functions.
                     $parts = explode('_', str_replace('.php', '', $file));
-                    $mimetype = $parts[0] . "/" . $parts[1];
+                    $mimetype = $parts[0] . '/' . $parts[1];
                     $stack['mimetype'][$mimetype] = $mimetype;
 
                     $stack[$prefix . 'transformation'][] = $mimetype . ': ' . $parts[2];
@@ -172,7 +172,7 @@ class Transformations
     public function getClassName($filename)
     {
         // get the transformation class name
-        $class_name = explode(".php", $filename);
+        $class_name = explode('.php', $filename);
         $class_name = 'PhpMyAdmin\\' . str_replace('/', '\\', mb_substr($class_name[0], 18));
 
         return $class_name;
@@ -230,12 +230,12 @@ class Transformations
     {
         $value = str_replace(
             [
-                "jpeg",
-                "png",
+                'jpeg',
+                'png',
             ],
             [
-                "JPEG",
-                "PNG",
+                'JPEG',
+                'PNG',
             ],
             $value
         );
@@ -271,11 +271,11 @@ class Transformations
 
         $com_qry = '';
         if ($fullName) {
-            $com_qry .= "SELECT CONCAT("
+            $com_qry .= 'SELECT CONCAT('
                 . "`db_name`, '.', `table_name`, '.', `column_name`"
-                . ") AS column_name, ";
+                . ') AS column_name, ';
         } else {
-            $com_qry  = "SELECT `column_name`, ";
+            $com_qry  = 'SELECT `column_name`, ';
         }
         $com_qry .= '`mimetype`,
                     `transformation`,
diff --git a/libraries/classes/Twig/I18n/NodeTrans.php b/libraries/classes/Twig/I18n/NodeTrans.php
index e7db92c2e1..e0bb40bfe5 100644
--- a/libraries/classes/Twig/I18n/NodeTrans.php
+++ b/libraries/classes/Twig/I18n/NodeTrans.php
@@ -90,7 +90,7 @@ class NodeTrans extends TransNode
 
             // line breaks are not allowed cause we want a single line comment
             $message = str_replace(["\n", "\r"], ' ', $message);
-            $compiler->write("// l10n: {$message}\n");
+            $compiler->write('// l10n: ' . $message . "\n");
         }
 
         if ($vars) {
diff --git a/libraries/classes/Types.php b/libraries/classes/Types.php
index ed30986d16..0eb3916ece 100644
--- a/libraries/classes/Types.php
+++ b/libraries/classes/Types.php
@@ -289,9 +289,9 @@ class Types
                 );
             case 'YEAR':
                 return __(
-                    "A year in four-digit (4, default) or two-digit (2) format, the " .
-                    "allowable values are 70 (1970) to 69 (2069) or 1901 to 2155 and " .
-                    "0000"
+                    'A year in four-digit (4, default) or two-digit (2) format, the ' .
+                    'allowable values are 70 (1970) to 69 (2069) or 1901 to 2155 and ' .
+                    '0000'
                 );
             case 'CHAR':
                 return __(
@@ -364,11 +364,11 @@ class Types
                 );
             case 'ENUM':
                 return __(
-                    "An enumeration, chosen from the list of up to 65,535 values or " .
+                    'An enumeration, chosen from the list of up to 65,535 values or ' .
                     "the special '' error value"
                 );
             case 'SET':
-                return __("A single value chosen from a set of up to 64 members");
+                return __('A single value chosen from a set of up to 64 members');
             case 'GEOMETRY':
                 return __('A type that can store a geometry of any type');
             case 'POINT':
diff --git a/libraries/classes/UserPassword.php b/libraries/classes/UserPassword.php
index 8e0568cca4..8cd156fad3 100644
--- a/libraries/classes/UserPassword.php
+++ b/libraries/classes/UserPassword.php
@@ -237,7 +237,7 @@ class UserPassword
 
             $hashedPassword = $this->serverPrivileges->getHashedPassword($_POST['pma_pw']);
 
-            $local_query = "UPDATE `mysql`.`user` SET"
+            $local_query = 'UPDATE `mysql`.`user` SET'
                 . " `authentication_string` = '" . $hashedPassword
                 . "', `Password` = '', "
                 . " `plugin` = '" . $orig_auth_plugin . "'"
@@ -259,7 +259,7 @@ class UserPassword
         }
 
         // Flush privileges after successful password change
-        $GLOBALS['dbi']->tryQuery("FLUSH PRIVILEGES;");
+        $GLOBALS['dbi']->tryQuery('FLUSH PRIVILEGES;');
     }
 
     /**
diff --git a/libraries/classes/Util.php b/libraries/classes/Util.php
index ab16bf399c..1fd6741f2e 100644
--- a/libraries/classes/Util.php
+++ b/libraries/classes/Util.php
@@ -406,7 +406,7 @@ class Util
             // 5.0.37 has profiling but for example, 5.1.20 does not
             // (avoid a trip to the server for MySQL before 5.0.37)
             // and do not set a constant as we might be switching servers
-            if ($GLOBALS['dbi']->fetchValue("SELECT @@have_profiling")
+            if ($GLOBALS['dbi']->fetchValue('SELECT @@have_profiling')
             ) {
                 self::cacheSet('profiling_supported', true);
             } else {
@@ -1421,10 +1421,10 @@ class Util
             // this would be a BINARY or VARBINARY column type;
             // by the way, a BLOB should not show the BINARY attribute
             // because this is not accepted in MySQL syntax.
-            if (false !== strpos($printtype, "binary")
+            if (false !== strpos($printtype, 'binary')
                 && ! preg_match('@binary[\(]@', $printtype)
             ) {
-                $printtype = str_replace("binary", '', $printtype);
+                $printtype = str_replace('binary', '', $printtype);
                 $binary = true;
             } else {
                 $binary = false;
@@ -1463,7 +1463,7 @@ class Util
         $can_contain_collation = false;
         if (! $binary
             && preg_match(
-                "@^(char|varchar|text|tinytext|mediumtext|longtext|set|enum)@",
+                '@^(char|varchar|text|tinytext|mediumtext|longtext|set|enum)@',
                 $type
             )
         ) {
@@ -1512,7 +1512,7 @@ class Util
             return true;
         } elseif ($engine == 'NDBCLUSTER' || $engine == 'NDB') {
             $ndbver = strtolower(
-                $GLOBALS['dbi']->fetchValue("SELECT @@ndb_version_string")
+                $GLOBALS['dbi']->fetchValue('SELECT @@ndb_version_string')
             );
             if (substr($ndbver, 0, 4) == 'ndb-') {
                 $ndbver = substr($ndbver, 4);
@@ -1592,9 +1592,9 @@ class Util
             $spatialAsText = 'ST_ASTEXT';
             $spatialSrid = 'ST_SRID';
         }
-        $wktsql     = "SELECT $spatialAsText(x'" . $hex . "')";
+        $wktsql     = 'SELECT ' . $spatialAsText . "(x'" . $hex . "')";
         if ($includeSRID) {
-            $wktsql .= ", $spatialSrid(x'" . $hex . "')";
+            $wktsql .= ', ' . $spatialSrid . "(x'" . $hex . "')";
         }
 
         $wktresult  = $GLOBALS['dbi']->tryQuery(
@@ -1909,7 +1909,7 @@ class Util
             . 'POLYGON|MULTIPOLYGON|GEOMETRYCOLLECTION)';
         if (preg_match("/^'" . $geom_types . "\(.*\)',[0-9]*$/i", $gis_string)) {
             return $geomFromText . '(' . $gis_string . ')';
-        } elseif (preg_match("/^" . $geom_types . "\(.*\)$/i", $gis_string)) {
+        } elseif (preg_match('/^' . $geom_types . '\(.*\)$/i', $gis_string)) {
             return $geomFromText . "('" . $gis_string . "')";
         }
 
@@ -2191,7 +2191,7 @@ class Util
         $username .= "''";
 
         // Prepare the query
-        $query = "SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`.`%s` "
+        $query = 'SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`.`%s` '
                . "WHERE GRANTEE='%s' AND PRIVILEGE_TYPE='%s'";
 
         // Check global privileges first.
@@ -2283,7 +2283,7 @@ class Util
      */
     public static function parseEnumSetValues($definition, $escapeHtml = true)
     {
-        $values_string = htmlentities($definition, ENT_COMPAT, "UTF-8");
+        $values_string = htmlentities($definition, ENT_COMPAT, 'UTF-8');
         // There is a JS port of the below parser in functions.js
         // If you are fixing something here,
         // you need to also update the JS port.
@@ -2299,13 +2299,13 @@ class Util
 
             if (! $in_string && $curr == "'") {
                 $in_string = true;
-            } elseif (($in_string && $curr == "\\") && $next == "\\") {
-                $buffer .= "&#92;";
+            } elseif (($in_string && $curr == '\\') && $next == '\\') {
+                $buffer .= '&#92;';
                 $i++;
             } elseif (($in_string && $next == "'")
-                && ($curr == "'" || $curr == "\\")
+                && ($curr == "'" || $curr == '\\')
             ) {
-                $buffer .= "&#39;";
+                $buffer .= '&#39;';
                 $i++;
             } elseif ($in_string && $curr == "'") {
                 $in_string = false;
@@ -2484,11 +2484,11 @@ class Util
     {
         $names = $GLOBALS['dbi']->getLowerCaseNames();
         if ($names === '0') {
-            return "COLLATE utf8_bin";
+            return 'COLLATE utf8_bin';
         } elseif ($names === '2') {
-            return "COLLATE utf8_general_ci";
+            return 'COLLATE utf8_general_ci';
         }
-        return "";
+        return '';
     }
 
     /**
@@ -2756,7 +2756,7 @@ class Util
 
         // is there at least one "in use" table?
         if (count($sot_cache) > 0) {
-            $tblGroupSql = "";
+            $tblGroupSql = '';
             $whereAdded = false;
             if (Core::isValid($_REQUEST['tbl_group'])) {
                 $group = self::escapeMysqlWildcards($_REQUEST['tbl_group']);
@@ -2764,16 +2764,16 @@ class Util
                     $_REQUEST['tbl_group']
                     . $GLOBALS['cfg']['NavigationTreeTableSeparator']
                 );
-                $tblGroupSql .= " WHERE ("
+                $tblGroupSql .= ' WHERE ('
                     . self::backquote('Tables_in_' . $db)
                     . " LIKE '" . $groupWithSeparator . "%'"
-                    . " OR "
+                    . ' OR '
                     . self::backquote('Tables_in_' . $db)
                     . " LIKE '" . $group . "')";
                 $whereAdded = true;
             }
             if (Core::isValid($_REQUEST['tbl_type'], ['table', 'view'])) {
-                $tblGroupSql .= $whereAdded ? " AND" : " WHERE";
+                $tblGroupSql .= $whereAdded ? ' AND' : ' WHERE';
                 if ($_REQUEST['tbl_type'] == 'view') {
                     $tblGroupSql .= " `Table_type` NOT IN ('BASE TABLE', 'SYSTEM VERSIONED')";
                 } else {
diff --git a/libraries/classes/Utils/HttpRequest.php b/libraries/classes/Utils/HttpRequest.php
index 45ec37765d..c484c5ad81 100644
--- a/libraries/classes/Utils/HttpRequest.php
+++ b/libraries/classes/Utils/HttpRequest.php
@@ -120,14 +120,14 @@ class HttpRequest
         }
         $curlStatus &= curl_setopt($curlHandle, CURLOPT_USERAGENT, 'phpMyAdmin');
 
-        if ($method != "GET") {
+        if ($method != 'GET') {
             $curlStatus &= curl_setopt($curlHandle, CURLOPT_CUSTOMREQUEST, $method);
         }
         if ($header) {
             $curlStatus &= curl_setopt($curlHandle, CURLOPT_HTTPHEADER, [$header]);
         }
 
-        if ($method == "POST") {
+        if ($method == 'POST') {
             $curlStatus &= curl_setopt($curlHandle, CURLOPT_POSTFIELDS, $content);
         }
 
@@ -208,13 +208,13 @@ class HttpRequest
                 'request_fulluri' => true,
                 'timeout' => 10,
                 'user_agent' => 'phpMyAdmin',
-                'header' => "Accept: */*",
+                'header' => 'Accept: */*',
             ],
         ];
         if ($header) {
             $context['http']['header'] .= "\n" . $header;
         }
-        if ($method == "POST") {
+        if ($method == 'POST') {
             $context['http']['content'] = $content;
         }
         $context = $this->handleContext($context);
@@ -224,7 +224,7 @@ class HttpRequest
             stream_context_create($context)
         );
         if (isset($http_response_header)) {
-            preg_match("#HTTP/[0-9\.]+\s+([0-9]+)#", $http_response_header[0], $out);
+            preg_match('#HTTP/[0-9\.]+\s+([0-9]+)#', $http_response_header[0], $out);
             $httpStatus = intval($out[1]);
             return $this->response($response, $httpStatus, $returnOnlyStatus);
         }
diff --git a/libraries/classes/VersionInformation.php b/libraries/classes/VersionInformation.php
index 3ac57c181b..2fffda7285 100644
--- a/libraries/classes/VersionInformation.php
+++ b/libraries/classes/VersionInformation.php
@@ -142,7 +142,7 @@ class VersionInformation
     {
         foreach ($releases as $release) {
             $phpVersions = $release->php_versions;
-            $phpConditions = explode(",", $phpVersions);
+            $phpConditions = explode(',', $phpVersions);
             foreach ($phpConditions as $phpCondition) {
                 if (! $this->evaluateVersionCondition('PHP', $phpCondition)) {
                     continue 2;
@@ -153,7 +153,7 @@ class VersionInformation
             // one server configured.
             if (count($GLOBALS['cfg']['Servers']) === 1) {
                 $mysqlVersions = $release->mysql_versions;
-                $mysqlConditions = explode(",", $mysqlVersions);
+                $mysqlConditions = explode(',', $mysqlVersions);
                 foreach ($mysqlConditions as $mysqlCondition) {
                     if (! $this->evaluateVersionCondition('MySQL', $mysqlCondition)) {
                         continue 2;
@@ -184,13 +184,13 @@ class VersionInformation
         $operator = null;
         $version = null;
         $operators = [
-            "<=",
-            ">=",
-            "!=",
-            "<>",
-            "<",
-            ">",
-            "=",
+            '<=',
+            '>=',
+            '!=',
+            '<>',
+            '<',
+            '>',
+            '=',
         ]; // preserve order
         foreach ($operators as $oneOperator) {
             if (strpos($condition, $oneOperator) === 0) {
diff --git a/libraries/config.default.php b/libraries/config.default.php
index 222e5c6fda..9609e09b9b 100644
--- a/libraries/config.default.php
+++ b/libraries/config.default.php
@@ -642,7 +642,7 @@ if (defined('VERSION_CHECK_DEFAULT')) {
  *
  * @global string $cfg['ProxyUrl']
  */
-$cfg['ProxyUrl'] = "";
+$cfg['ProxyUrl'] = '';
 
 /**
  * The username for authenticating with the proxy. By default, no
@@ -652,14 +652,14 @@ $cfg['ProxyUrl'] = "";
  *
  * @global string $cfg['ProxyUser']
  */
-$cfg['ProxyUser'] = "";
+$cfg['ProxyUser'] = '';
 
 /**
  * The password for authenticating with the proxy.
  *
  * @global string $cfg['ProxyPass']
  */
-$cfg['ProxyPass'] = "";
+$cfg['ProxyPass'] = '';
 
 /**
  * maximum number of db's displayed in database list
diff --git a/libraries/entry_points/database/operations.php b/libraries/entry_points/database/operations.php
index 68eb5d395b..65dfabbf40 100644
--- a/libraries/entry_points/database/operations.php
+++ b/libraries/entry_points/database/operations.php
@@ -103,8 +103,8 @@ if (strlen($db) > 0
             // remove all foreign key constraints, otherwise we can get errors
             /** @var ExportSql $export_sql_plugin */
             $export_sql_plugin = Plugins::getPlugin(
-                "export",
-                "sql",
+                'export',
+                'sql',
                 'libraries/classes/Plugins/Export/',
                 [
                     'single_table' => isset($single_table),
diff --git a/libraries/entry_points/database/sql/autocomplete.php b/libraries/entry_points/database/sql/autocomplete.php
index a04010baf2..4d7fd8aa20 100644
--- a/libraries/entry_points/database/sql/autocomplete.php
+++ b/libraries/entry_points/database/sql/autocomplete.php
@@ -37,4 +37,4 @@ if ($GLOBALS['cfg']['EnableAutocompleteForTablesAndColumns']) {
     $sql_autocomplete = true;
 }
 
-$response->addJSON("tables", json_encode($sql_autocomplete));
+$response->addJSON('tables', json_encode($sql_autocomplete));
diff --git a/libraries/entry_points/database/sql/format.php b/libraries/entry_points/database/sql/format.php
index e3264cf5f0..0881da50ed 100644
--- a/libraries/entry_points/database/sql/format.php
+++ b/libraries/entry_points/database/sql/format.php
@@ -17,4 +17,4 @@ $query = ! empty($_POST['sql']) ? $_POST['sql'] : '';
 $query = PhpMyAdmin\SqlParser\Utils\Formatter::format($query);
 
 $response = Response::getInstance();
-$response->addJSON("sql", $query);
+$response->addJSON('sql', $query);
diff --git a/libraries/entry_points/export.php b/libraries/entry_points/export.php
index b41f143fa1..4ccbd1ddc1 100644
--- a/libraries/entry_points/export.php
+++ b/libraries/entry_points/export.php
@@ -53,9 +53,9 @@ if (isset($_GET['check_time_out'])) {
     if (isset($_SESSION['pma_export_error'])) {
         $err = $_SESSION['pma_export_error'];
         unset($_SESSION['pma_export_error']);
-        echo "timeout";
+        echo 'timeout';
     } else {
-        echo "success";
+        echo 'success';
     }
     exit;
 }
@@ -203,7 +203,7 @@ $what = Core::securePath($_POST['what']);
 // export class instance, not array of properties, as before
 /** @var ExportPlugin $export_plugin */
 $export_plugin = Plugins::getPlugin(
-    "export",
+    'export',
     $what,
     'libraries/classes/Plugins/Export/',
     [
@@ -491,7 +491,7 @@ try {
             $table_data = $tables;
         }
         if (isset($lock_tables)) {
-            $export->lockTables($db, $tables, "READ");
+            $export->lockTables($db, $tables, 'READ');
             try {
                 $export->exportDatabase(
                     $db,
@@ -546,7 +546,7 @@ try {
         }
         if (isset($lock_tables)) {
             try {
-                $export->lockTables($db, [$table], "READ");
+                $export->lockTables($db, [$table], 'READ');
                 $export->exportTable(
                     $db,
                     $table,
diff --git a/libraries/entry_points/import.php b/libraries/entry_points/import.php
index 6e547fd89e..636083a66c 100644
--- a/libraries/entry_points/import.php
+++ b/libraries/entry_points/import.php
@@ -550,7 +550,7 @@ if (! $error) {
      * @var ImportPlugin $import_plugin
      */
     $import_plugin = Plugins::getPlugin(
-        "import",
+        'import',
         $format,
         'libraries/classes/Plugins/Import/',
         $import_type
diff --git a/libraries/entry_points/normalization.php b/libraries/entry_points/normalization.php
index 7e09830863..e5eb39723a 100644
--- a/libraries/entry_points/normalization.php
+++ b/libraries/entry_points/normalization.php
@@ -49,7 +49,7 @@ if (isset($_POST['splitColumn'])) {
 if (isset($_POST['addNewPrimary'])) {
     $num_fields = 1;
     $columnMeta = [
-        'Field' => $table . "_id",
+        'Field' => $table . '_id',
         'Extra' => 'auto_increment',
     ];
     $html = $normalization->getHtmlForCreateNewColumn(
diff --git a/libraries/entry_points/server/privileges.php b/libraries/entry_points/server/privileges.php
index dcf94f2660..6d21b7bed3 100644
--- a/libraries/entry_points/server/privileges.php
+++ b/libraries/entry_points/server/privileges.php
@@ -215,7 +215,7 @@ if (isset($_POST['change_copy']) && $username == $_POST['old_username']
         Message::error(
             __(
                 "Username and hostname didn't change. "
-                . "If you only want to change the password, "
+                . 'If you only want to change the password, '
                 . "'Change password' tab should be used."
             )
         )->getDisplay()
@@ -453,7 +453,7 @@ if (isset($_GET['export'])
         $response->addJSON('title', $title);
         exit;
     } else {
-        $response->addHTML("<h2>$title</h2>$export");
+        $response->addHTML('<h2>' . $title . '</h2>' . $export);
     }
 }
 
diff --git a/libraries/entry_points/sql.php b/libraries/entry_points/sql.php
index 1f0fee0427..d80566db9b 100644
--- a/libraries/entry_points/sql.php
+++ b/libraries/entry_points/sql.php
@@ -115,14 +115,14 @@ if (isset($_POST['get_relational_values'])
 
 // Just like above, find possible values for enum fields during grid edit.
 if (isset($_POST['get_enum_values']) && $_POST['get_enum_values'] == true) {
-    $sql->getEnumOrSetValues($db, $table, "enum");
+    $sql->getEnumOrSetValues($db, $table, 'enum');
     // script has exited at this point
 }
 
 
 // Find possible values for set fields during grid edit.
 if (isset($_POST['get_set_values']) && $_POST['get_set_values'] == true) {
-    $sql->getEnumOrSetValues($db, $table, "set");
+    $sql->getEnumOrSetValues($db, $table, 'set');
     // script has exited at this point
 }
 
diff --git a/libraries/entry_points/table/replace.php b/libraries/entry_points/table/replace.php
index 1fdbdb4c0f..1a786de1b0 100644
--- a/libraries/entry_points/table/replace.php
+++ b/libraries/entry_points/table/replace.php
@@ -489,8 +489,8 @@ if ($response->isAjax() && ! isset($_POST['ajax_page_request'])) {
             $extra_data = [];
         }
         $transformation_types = [
-            "input_transformation",
-            "transformation",
+            'input_transformation',
+            'transformation',
         ];
         foreach ($mime_map as $transformation) {
             $column_name = $transformation['column_name'];
diff --git a/libraries/entry_points/table/tracking.php b/libraries/entry_points/table/tracking.php
index ed9336270a..9428a7567a 100644
--- a/libraries/entry_points/table/tracking.php
+++ b/libraries/entry_points/table/tracking.php
@@ -34,7 +34,7 @@ require ROOT_PATH . 'libraries/tbl_common.inc.php';
 $tracking = $containerBuilder->get('tracking');
 
 if (Tracker::isActive()
-    && Tracker::isTracked($GLOBALS["db"], $GLOBALS["table"])
+    && Tracker::isTracked($GLOBALS['db'], $GLOBALS['table'])
     && ! (isset($_POST['toggle_activation'])
     && $_POST['toggle_activation'] == 'deactivate_now')
     && ! (isset($_POST['report_export'])
@@ -43,7 +43,7 @@ if (Tracker::isActive()
     $msg = Message::notice(
         sprintf(
             __('Tracking of %s is activated.'),
-            htmlspecialchars($GLOBALS["db"] . '.' . $GLOBALS["table"])
+            htmlspecialchars($GLOBALS['db'] . '.' . $GLOBALS['table'])
         )
     );
     $response->addHTML($msg->getDisplay());
diff --git a/libraries/entry_points/view/create.php b/libraries/entry_points/view/create.php
index 1c3a0c51bd..486dd42759 100644
--- a/libraries/entry_points/view/create.php
+++ b/libraries/entry_points/view/create.php
@@ -128,7 +128,7 @@ if (isset($_POST['createview']) || isset($_POST['alterview'])) {
         $response->addJSON(
             'message',
             Message::error(
-                "<i>" . htmlspecialchars($sql_query) . "</i><br><br>"
+                '<i>' . htmlspecialchars($sql_query) . '</i><br><br>'
                 . $dbi->getError()
             )
         );
@@ -217,7 +217,7 @@ if (isset($_GET['db'], $_GET['table'])) {
         ->showCreate();
 
     // CREATE ALGORITHM=<ALGORITHM> DE...
-    $parts = explode(" ", substr($createView, 17));
+    $parts = explode(' ', substr($createView, 17));
     $item['ALGORITHM'] = $parts[0];
 
     $view['operation'] = 'alter';
diff --git a/libraries/replication.inc.php b/libraries/replication.inc.php
index 66f4ac43a1..724559de2a 100644
--- a/libraries/replication.inc.php
+++ b/libraries/replication.inc.php
@@ -130,13 +130,13 @@ $slave_variables_oks = [
 $replication_info = [];
 
 foreach ($replication_types as $type) {
-    if (count(${"server_{$type}_replication"}) > 0) {
+    if (count(${'server_' . $type . '_replication'}) > 0) {
         $replication_info[$type]['status'] = true;
     } else {
         $replication_info[$type]['status'] = false;
     }
     if ($replication_info[$type]['status']) {
-        if ($type == "master") {
+        if ($type == 'master') {
             $replication->fillInfo(
                 $type,
                 'Do_DB',
@@ -150,7 +150,7 @@ foreach ($replication_types as $type) {
                 $server_master_replication[0],
                 'Binlog_Ignore_DB'
             );
-        } elseif ($type == "slave") {
+        } elseif ($type == 'slave') {
             $replication->fillInfo(
                 $type,
                 'Do_DB',
diff --git a/libraries/tbl_columns_definition_form.inc.php b/libraries/tbl_columns_definition_form.inc.php
index bd65716f32..9c3da644f6 100644
--- a/libraries/tbl_columns_definition_form.inc.php
+++ b/libraries/tbl_columns_definition_form.inc.php
@@ -271,14 +271,14 @@ for ($columnNumber = 0; $columnNumber < $num_fields; $columnNumber++) {
         $mime_map[$columnMeta['Field']] = array_merge(
             $mime_map[$columnMeta['Field']],
             [
-                'mimetype' => Util::getValueByKey($_POST, "field_mimetype.${$columnNumber}"),
+                'mimetype' => Util::getValueByKey($_POST, "field_mimetype.${columnNumber}"),
                 'transformation' => Util::getValueByKey(
                     $_POST,
-                    "field_transformation.${$columnNumber}"
+                    "field_transformation.${columnNumber}"
                 ),
                 'transformation_options' => Util::getValueByKey(
                     $_POST,
-                    "field_transformation_options.${$columnNumber}"
+                    "field_transformation_options.${columnNumber}"
                 ),
             ]
         );
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index fc387d7abd..ccc4b7522a 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -37,6 +37,8 @@
         <exclude name="Squiz.Arrays.ArrayDeclaration.SingleLineNotAllowed"/>
     </rule>
 
+    <rule ref="Squiz.Strings.DoubleQuoteUsage"/>
+
     <arg value="sp"/>
     <arg name="colors"/>
     <arg name="extensions" value="php"/>
diff --git a/test/bootstrap-dist.php b/test/bootstrap-dist.php
index 14f39bb44b..68653ca031 100644
--- a/test/bootstrap-dist.php
+++ b/test/bootstrap-dist.php
@@ -32,7 +32,7 @@ date_default_timezone_set('UTC');
 
 // Adding phpMyAdmin sources to include path
 set_include_path(
-    get_include_path() . PATH_SEPARATOR . dirname((string) realpath("../index.php"))
+    get_include_path() . PATH_SEPARATOR . dirname((string) realpath('../index.php'))
 );
 
 // Setting constants for testing
diff --git a/test/classes/AdvisorTest.php b/test/classes/AdvisorTest.php
index 53ca50be0f..616537853a 100644
--- a/test/classes/AdvisorTest.php
+++ b/test/classes/AdvisorTest.php
@@ -111,23 +111,23 @@ class AdvisorTest extends PmaTestCase
         return [
             [
                 10,
-                "10 per second",
+                '10 per second',
             ],
             [
                 0.02,
-                "1.2 per minute",
+                '1.2 per minute',
             ],
             [
                 0.003,
-                "10.8 per hour",
+                '10.8 per hour',
             ],
             [
                 0.00003,
-                "2.59 per day",
+                '2.59 per day',
             ],
             [
                 0.0000000003,
-                "<0.01 per day",
+                '<0.01 per day',
             ],
         ];
     }
@@ -140,10 +140,10 @@ class AdvisorTest extends PmaTestCase
     public function testAdvisorTimespanFormat()
     {
         $result = Advisor::timespanFormat(1200);
-        $this->assertEquals("0 days, 0 hours, 20 minutes and 0 seconds", $result);
+        $this->assertEquals('0 days, 0 hours, 20 minutes and 0 seconds', $result);
 
         $result = Advisor::timespanFormat(100);
-        $this->assertEquals("0 days, 0 hours, 1 minutes and 40 seconds", $result);
+        $this->assertEquals('0 days, 0 hours, 1 minutes and 40 seconds', $result);
     }
 
     /**
diff --git a/test/classes/CentralColumnsTest.php b/test/classes/CentralColumnsTest.php
index 6df3456dec..93497fa30f 100644
--- a/test/classes/CentralColumnsTest.php
+++ b/test/classes/CentralColumnsTest.php
@@ -31,8 +31,8 @@ class CentralColumnsTest extends TestCase
 
     private $columnData = [
         [
-            'col_name' => "id",
-            "col_type" => 'integer',
+            'col_name' => 'id',
+            'col_type' => 'integer',
             'col_length' => 0,
             'col_isNull' => 0,
             'col_extra' => 'UNSIGNED,auto_increment',
@@ -40,7 +40,7 @@ class CentralColumnsTest extends TestCase
             'col_collation' => '',
         ],
         [
-            'col_name' => "col1",
+            'col_name' => 'col1',
             'col_type' => 'varchar',
             'col_length' => 100,
             'col_isNull' => 1,
@@ -49,7 +49,7 @@ class CentralColumnsTest extends TestCase
             'col_collation' => '',
         ],
         [
-            'col_name' => "col2",
+            'col_name' => 'col2',
             'col_type' => 'DATETIME',
             'col_length' => 0,
             'col_isNull' => 1,
@@ -61,8 +61,8 @@ class CentralColumnsTest extends TestCase
 
     private $modifiedColumnData = [
         [
-            'col_name' => "id",
-            "col_type" => 'integer',
+            'col_name' => 'id',
+            'col_type' => 'integer',
             'col_length' => 0,
             'col_isNull' => 0,
             'col_extra' => 'auto_increment',
@@ -71,7 +71,7 @@ class CentralColumnsTest extends TestCase
             'col_attribute' => 'UNSIGNED',
         ],
         [
-            'col_name' => "col1",
+            'col_name' => 'col1',
             'col_type' => 'varchar',
             'col_length' => 100,
             'col_isNull' => 1,
@@ -81,7 +81,7 @@ class CentralColumnsTest extends TestCase
             'col_attribute' => 'BINARY',
         ],
         [
-            'col_name' => "col2",
+            'col_name' => 'col2',
             'col_type' => 'DATETIME',
             'col_length' => 0,
             'col_isNull' => 1,
@@ -103,7 +103,7 @@ class CentralColumnsTest extends TestCase
         $GLOBALS['cfg']['Server']['user'] = 'pma_user';
         $GLOBALS['cfg']['Server']['DisableIS'] = true;
         $GLOBALS['cfg']['MaxRows'] = 10;
-        $GLOBALS['cfg']['ServerDefault'] = "PMA_server";
+        $GLOBALS['cfg']['ServerDefault'] = 'PMA_server';
         $GLOBALS['cfg']['ActionLinksMode'] = 'icons';
         $GLOBALS['cfg']['CharEditing'] = '';
         $GLOBALS['cfg']['LimitChars'] = 50;
@@ -137,31 +137,31 @@ class CentralColumnsTest extends TestCase
             ->will(
                 $this->returnValue(
                     [
-                        "id" => [
-                            "Type" => "integer",
-                            "Null" => "NO",
+                        'id' => [
+                            'Type' => 'integer',
+                            'Null' => 'NO',
                         ],
-                        "col1" => [
-                            "Type" => 'varchar(100)',
-                            "Null" => "YES",
+                        'col1' => [
+                            'Type' => 'varchar(100)',
+                            'Null' => 'YES',
                         ],
-                        "col2" => [
-                            "Type" => 'DATETIME',
-                            "Null" => "NO",
+                        'col2' => [
+                            'Type' => 'DATETIME',
+                            'Null' => 'NO',
                         ],
                     ]
                 )
             );
         $dbi->expects($this->any())
             ->method('getColumnNames')
-            ->will($this->returnValue(["id", "col1", "col2"]));
+            ->will($this->returnValue(['id', 'col1', 'col2']));
         $dbi->expects($this->any())
             ->method('tryQuery')
             ->will($this->returnValue(true));
         $dbi->expects($this->any())
             ->method('getTables')
             ->will(
-                $this->returnValue(["PMA_table", "PMA_table1", "PMA_table2"])
+                $this->returnValue(['PMA_table', 'PMA_table1', 'PMA_table2'])
             );
         $dbi->expects($this->any())->method('escapeString')
             ->will($this->returnArgument(0));
@@ -243,7 +243,7 @@ class CentralColumnsTest extends TestCase
         $GLOBALS['dbi']->expects($this->once())
             ->method('fetchResult')
             ->with(
-                "SELECT count(db_name) FROM `pma_central_columns` "
+                'SELECT count(db_name) FROM `pma_central_columns` '
                 . "WHERE db_name = 'phpmyadmin';",
                 null,
                 null,
@@ -290,7 +290,7 @@ class CentralColumnsTest extends TestCase
         $GLOBALS['dbi']->expects($this->at(4))
             ->method('fetchResult')
             ->with(
-                "SELECT col_name FROM `pma_central_columns` "
+                'SELECT col_name FROM `pma_central_columns` '
                 . "WHERE db_name = 'PMA_db' AND col_name IN ('col1');",
                 null,
                 null,
@@ -303,7 +303,7 @@ class CentralColumnsTest extends TestCase
         $GLOBALS['dbi']->expects($this->at(7))
             ->method('tryQuery')
             ->with(
-                "DELETE FROM `pma_central_columns` "
+                'DELETE FROM `pma_central_columns` '
                 . "WHERE db_name = 'PMA_db' AND col_name IN ('col1');",
                 DatabaseInterface::CONNECT_CONTROL
             )
@@ -314,7 +314,7 @@ class CentralColumnsTest extends TestCase
         $this->assertTrue(
             $this->centralColumns->deleteColumnsFromList(
                 $_POST['db'],
-                ["col1"],
+                ['col1'],
                 false
             )
         );
@@ -357,7 +357,7 @@ class CentralColumnsTest extends TestCase
             );
         $this->assertTrue(
             $this->centralColumns->makeConsistentWithList(
-                "phpmyadmin",
+                'phpmyadmin',
                 ['PMA_table']
             )
         );
@@ -376,7 +376,7 @@ class CentralColumnsTest extends TestCase
         $GLOBALS['dbi']->expects($this->once())
             ->method('fetchResult')
             ->with(
-                "SELECT col_name FROM `pma_central_columns` "
+                'SELECT col_name FROM `pma_central_columns` '
                 . "WHERE db_name = 'PMA_db' AND col_name IN ('id','col1','col2');",
                 null,
                 null,
@@ -387,8 +387,8 @@ class CentralColumnsTest extends TestCase
             );
         $this->assertEquals(
             [
-                "id",
-                "col1",
+                'id',
+                'col1',
             ],
             $this->centralColumns->getFromTable(
                 $db,
@@ -410,7 +410,7 @@ class CentralColumnsTest extends TestCase
         $GLOBALS['dbi']->expects($this->once())
             ->method('fetchResult')
             ->with(
-                "SELECT * FROM `pma_central_columns` "
+                'SELECT * FROM `pma_central_columns` '
                 . "WHERE db_name = 'PMA_db' AND col_name IN ('id','col1','col2');",
                 null,
                 null,
@@ -438,30 +438,30 @@ class CentralColumnsTest extends TestCase
     {
         $this->assertTrue(
             $this->centralColumns->updateOneColumn(
-                "phpmyadmin",
-                "",
-                "",
-                "",
-                "",
-                "",
+                'phpmyadmin',
+                '',
+                '',
+                '',
+                '',
+                '',
                 0,
-                "",
-                "",
-                ""
+                '',
+                '',
+                ''
             )
         );
         $this->assertTrue(
             $this->centralColumns->updateOneColumn(
-                "phpmyadmin",
-                "col1",
-                "",
-                "",
-                "",
-                "",
+                'phpmyadmin',
+                'col1',
+                '',
+                '',
+                '',
+                '',
                 0,
-                "",
-                "",
-                ""
+                '',
+                '',
+                ''
             )
         );
     }
@@ -475,36 +475,36 @@ class CentralColumnsTest extends TestCase
     {
         $params['db'] = 'phpmyadmin';
         $params['orig_col_name'] = [
-            "col1",
-            "col2",
+            'col1',
+            'col2',
         ];
         $params['field_name'] = [
-            "col1",
-            "col2",
+            'col1',
+            'col2',
         ];
         $params['field_default_type'] = [
-            "",
-            "",
+            '',
+            '',
         ];
         $params['col_extra'] = [
-            "",
-            "",
+            '',
+            '',
         ];
         $params['field_length'] = [
-            "",
-            "",
+            '',
+            '',
         ];
         $params['field_attribute'] = [
-            "",
-            "",
+            '',
+            '',
         ];
         $params['field_type'] = [
-            "",
-            "",
+            '',
+            '',
         ];
         $params['field_collation'] = [
-            "",
-            "",
+            '',
+            '',
         ];
         $this->assertTrue(
             $this->centralColumns->updateMultipleColumn($params)
@@ -521,7 +521,7 @@ class CentralColumnsTest extends TestCase
         $GLOBALS['dbi']->expects($this->any())
             ->method('fetchResult')
             ->with(
-                "SELECT * FROM `pma_central_columns` "
+                'SELECT * FROM `pma_central_columns` '
                 . "WHERE db_name = 'phpmyadmin' AND col_name IN ('col1','col2');",
                 null,
                 null,
@@ -532,8 +532,8 @@ class CentralColumnsTest extends TestCase
             );
         $result = $this->centralColumns->getHtmlForEditingPage(
             [
-                "col1",
-                "col2",
+                'col1',
+                'col2',
             ],
             'phpmyadmin'
         );
@@ -592,7 +592,7 @@ class CentralColumnsTest extends TestCase
         $GLOBALS['dbi']->expects($this->once())
             ->method('fetchResult')
             ->with(
-                "SELECT * FROM `pma_central_columns` "
+                'SELECT * FROM `pma_central_columns` '
                 . "WHERE db_name = 'phpmyadmin';",
                 null,
                 null,
@@ -620,7 +620,7 @@ class CentralColumnsTest extends TestCase
         $GLOBALS['dbi']->expects($this->once())
             ->method('fetchResult')
             ->with(
-                "SELECT * FROM `pma_central_columns` "
+                'SELECT * FROM `pma_central_columns` '
                 . "WHERE db_name = 'phpmyadmin' AND col_name "
                 . "NOT IN ('id','col1','col2');",
                 null,
@@ -649,8 +649,8 @@ class CentralColumnsTest extends TestCase
         $db = 'phpmyadmin';
         $total_rows = 50;
         $pos = 26;
-        $pmaThemeImage = "pmaThemeImage";
-        $text_dir = "text_dir";
+        $pmaThemeImage = 'pmaThemeImage';
+        $text_dir = 'text_dir';
         $max_rows = (int) $GLOBALS['cfg']['MaxRows'];
         // test for not empty table
         $result = $this->centralColumns->getHtmlForMain(
@@ -778,14 +778,14 @@ class CentralColumnsTest extends TestCase
      */
     public function testGetTableFooter()
     {
-        $pmaThemeImage = "pmaThemeImage";
-        $text_dir = "text_dir";
+        $pmaThemeImage = 'pmaThemeImage';
+        $text_dir = 'text_dir';
         $result = $this->centralColumns->getTableFooter($pmaThemeImage, $text_dir);
         $this->assertStringContainsString(
             '<input type="checkbox" id="tableslistcontainer_checkall" class="checkall_box"',
             $result
         );
-        $this->assertStringContainsString("With selected:", $result);
+        $this->assertStringContainsString('With selected:', $result);
         $this->assertStringContainsString(
             '<button class="btn btn-link mult_submit change_central_columns"',
             $result
diff --git a/test/classes/CheckUserPrivilegesTest.php b/test/classes/CheckUserPrivilegesTest.php
index 1024174421..20cd3ce71e 100644
--- a/test/classes/CheckUserPrivilegesTest.php
+++ b/test/classes/CheckUserPrivilegesTest.php
@@ -49,7 +49,7 @@ class CheckUserPrivilegesTest extends TestCase
     public function testGetItemsFromShowGrantsRow()
     {
         // TEST CASE 1
-        $show_grants_full_row = "GRANT ALL PRIVILEGES ON *.* "
+        $show_grants_full_row = 'GRANT ALL PRIVILEGES ON *.* '
             . "TO 'root'@'localhost' WITH GRANT OPTION";
 
         list(
@@ -61,22 +61,22 @@ class CheckUserPrivilegesTest extends TestCase
         );
 
         $this->assertEquals(
-            "ALL PRIVILEGES",
+            'ALL PRIVILEGES',
             $show_grants_str
         );
 
         $this->assertEquals(
-            "*",
+            '*',
             $show_grants_dbname
         );
 
         $this->assertEquals(
-            "*",
+            '*',
             $show_grants_tblname
         );
 
         // TEST CASE 2
-        $show_grants_full_row = "GRANT ALL PRIVILEGES ON `mysql`.* TO "
+        $show_grants_full_row = 'GRANT ALL PRIVILEGES ON `mysql`.* TO '
             . "'root'@'localhost' WITH GRANT OPTION";
 
         list(
@@ -88,22 +88,22 @@ class CheckUserPrivilegesTest extends TestCase
         );
 
         $this->assertEquals(
-            "ALL PRIVILEGES",
+            'ALL PRIVILEGES',
             $show_grants_str
         );
 
         $this->assertEquals(
-            "mysql",
+            'mysql',
             $show_grants_dbname
         );
 
         $this->assertEquals(
-            "*",
+            '*',
             $show_grants_tblname
         );
 
         // TEST CASE 3
-        $show_grants_full_row = "GRANT SELECT, INSERT, UPDATE, DELETE "
+        $show_grants_full_row = 'GRANT SELECT, INSERT, UPDATE, DELETE '
             . "ON `mysql`.`columns_priv` TO 'root'@'localhost'";
 
         list(
@@ -115,22 +115,22 @@ class CheckUserPrivilegesTest extends TestCase
         );
 
         $this->assertEquals(
-            "SELECT, INSERT, UPDATE, DELETE",
+            'SELECT, INSERT, UPDATE, DELETE',
             $show_grants_str
         );
 
         $this->assertEquals(
-            "mysql",
+            'mysql',
             $show_grants_dbname
         );
 
         $this->assertEquals(
-            "columns_priv",
+            'columns_priv',
             $show_grants_tblname
         );
 
         // TEST CASE 4
-        $show_grants_full_row = "GRANT ALL PRIVILEGES ON `cptest\_.`.* TO "
+        $show_grants_full_row = 'GRANT ALL PRIVILEGES ON `cptest\_.`.* TO '
             . "'cptest'@'localhost'";
 
         list(
@@ -142,11 +142,11 @@ class CheckUserPrivilegesTest extends TestCase
         );
 
         $this->assertEquals(
-            "cptest\_.",
+            'cptest\_.',
             $show_grants_dbname
         );
 
-        $show_grants_full_row = "GRANT ALL PRIVILEGES ON `cptest\_.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z`.* TO "
+        $show_grants_full_row = 'GRANT ALL PRIVILEGES ON `cptest\_.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z`.* TO '
             . "'cptest'@'localhost'";
 
         list(
@@ -158,7 +158,7 @@ class CheckUserPrivilegesTest extends TestCase
         );
 
         $this->assertEquals(
-            "cptest\_.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z",
+            'cptest\_.a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z',
             $show_grants_dbname
         );
     }
@@ -171,7 +171,7 @@ class CheckUserPrivilegesTest extends TestCase
     public function testCheckRequiredPrivilegesForAdjust()
     {
         // TEST CASE 1
-        $show_grants_full_row = "GRANT ALL PRIVILEGES ON *.* "
+        $show_grants_full_row = 'GRANT ALL PRIVILEGES ON *.* '
             . "TO 'root'@'localhost' WITH GRANT OPTION";
         list(
             $show_grants_str,
@@ -212,7 +212,7 @@ class CheckUserPrivilegesTest extends TestCase
         $this->setUp();
 
         // TEST CASE 2
-        $show_grants_full_row = "GRANT ALL PRIVILEGES ON `mysql`.* TO "
+        $show_grants_full_row = 'GRANT ALL PRIVILEGES ON `mysql`.* TO '
             . "'root'@'localhost' WITH GRANT OPTION";
         list(
             $show_grants_str,
@@ -253,7 +253,7 @@ class CheckUserPrivilegesTest extends TestCase
         $this->setUp();
 
         // TEST CASE 3
-        $show_grants_full_row = "GRANT SELECT, INSERT, UPDATE, DELETE ON "
+        $show_grants_full_row = 'GRANT SELECT, INSERT, UPDATE, DELETE ON '
             . "`mysql`.* TO 'root'@'localhost'";
         list(
             $show_grants_str,
@@ -294,7 +294,7 @@ class CheckUserPrivilegesTest extends TestCase
         $this->setUp();
 
         // TEST CASE 4
-        $show_grants_full_row = "GRANT SELECT, INSERT, UPDATE, DELETE ON "
+        $show_grants_full_row = 'GRANT SELECT, INSERT, UPDATE, DELETE ON '
             . "`mysql`.`db` TO 'root'@'localhost'";
         list(
             $show_grants_str,
diff --git a/test/classes/Config/ConfigFileTest.php b/test/classes/Config/ConfigFileTest.php
index 2d6ebf447f..bbedef777d 100644
--- a/test/classes/Config/ConfigFileTest.php
+++ b/test/classes/Config/ConfigFileTest.php
@@ -71,7 +71,7 @@ class ConfigFileTest extends PmaTestCase
         // Check environment state
         $this->assertEquals(
             [],
-            $_SESSION["ConfigFile1"]
+            $_SESSION['ConfigFile1']
         );
 
         // Validate default value used in tests
@@ -399,13 +399,13 @@ class ConfigFileTest extends PmaTestCase
     public function testGetCanonicalPath()
     {
         $this->assertEquals(
-            "Servers/1/abcd",
-            $this->object->getCanonicalPath("Servers/2/abcd")
+            'Servers/1/abcd',
+            $this->object->getCanonicalPath('Servers/2/abcd')
         );
 
         $this->assertEquals(
-            "Servers/foo/bar",
-            $this->object->getCanonicalPath("Servers/foo/bar")
+            'Servers/foo/bar',
+            $this->object->getCanonicalPath('Servers/foo/bar')
         );
     }
 
@@ -518,16 +518,16 @@ class ConfigFileTest extends PmaTestCase
             [
                 'Servers' => [
                     1 => [
-                        "auth_type" => "config",
-                        "user" => "testUser",
-                        "host" => "example.com",
-                        "port" => "21",
+                        'auth_type' => 'config',
+                        'user' => 'testUser',
+                        'host' => 'example.com',
+                        'port' => '21',
                     ],
                 ],
             ]
         );
         $this->assertEquals(
-            "mysqli://testUser@example.com:21",
+            'mysqli://testUser@example.com:21',
             $this->object->getServerDSN(1)
         );
 
@@ -535,18 +535,18 @@ class ConfigFileTest extends PmaTestCase
             [
                 'Servers' => [
                     1 => [
-                        "auth_type" => "config",
-                        "user" => "testUser",
-                        "host" => "localhost",
-                        "port" => "21",
-                        "socket" => "123",
-                        "password" => "",
+                        'auth_type' => 'config',
+                        'user' => 'testUser',
+                        'host' => 'localhost',
+                        'port' => '21',
+                        'socket' => '123',
+                        'password' => '',
                     ],
                 ],
             ]
         );
         $this->assertEquals(
-            "mysqli://testUser@123",
+            'mysqli://testUser@123',
             $this->object->getServerDSN(1)
         );
 
@@ -554,17 +554,17 @@ class ConfigFileTest extends PmaTestCase
             [
                 'Servers' => [
                     1 => [
-                        "auth_type" => "config",
-                        "user" => "testUser",
-                        "host" => "example.com",
-                        "port" => "21",
-                        "password" => "testPass",
+                        'auth_type' => 'config',
+                        'user' => 'testUser',
+                        'host' => 'example.com',
+                        'port' => '21',
+                        'password' => 'testPass',
                     ],
                 ],
             ]
         );
         $this->assertEquals(
-            "mysqli://testUser:***@example.com:21",
+            'mysqli://testUser:***@example.com:21',
             $this->object->getServerDSN(1)
         );
     }
diff --git a/test/classes/Config/FormDisplayTemplateTest.php b/test/classes/Config/FormDisplayTemplateTest.php
index 5c6196a98f..9999596d85 100644
--- a/test/classes/Config/FormDisplayTemplateTest.php
+++ b/test/classes/Config/FormDisplayTemplateTest.php
@@ -121,7 +121,7 @@ class FormDisplayTemplateTest extends TestCase
             'e2',
         ];
 
-        $result = $this->formDisplayTemplate->displayFieldsetTop("TitleTest", "DescTest", $errors, $attributes);
+        $result = $this->formDisplayTemplate->displayFieldsetTop('TitleTest', 'DescTest', $errors, $attributes);
 
         $this->assertStringContainsString(
             '<fieldset class="optbox" name="attrname">',
@@ -165,8 +165,8 @@ class FormDisplayTemplateTest extends TestCase
         $opts['errors'] = ['e1'];
         $opts['userprefs_allow'] = false;
         $opts['setvalue'] = ':group';
-        $opts['doc'] = "https://example.com/";
-        $opts['comment'] = "testComment";
+        $opts['doc'] = 'https://example.com/';
+        $opts['comment'] = 'testComment';
         $opts['comment_warning'] = true;
         $opts['show_restore_default'] = true;
         $result = $this->formDisplayTemplate->displayInput(
@@ -232,7 +232,7 @@ class FormDisplayTemplateTest extends TestCase
         $opts = [];
         $opts['errors'] = [];
         $opts['setvalue'] = 'setVal';
-        $opts['comment'] = "testComment";
+        $opts['comment'] = 'testComment';
         $opts['show_restore_default'] = true;
         $opts['userprefs_comment'] = 'userprefsComment';
         $opts['userprefs_allow'] = true;
diff --git a/test/classes/Config/FormDisplayTest.php b/test/classes/Config/FormDisplayTest.php
index 47c369e12b..a07bd51503 100644
--- a/test/classes/Config/FormDisplayTest.php
+++ b/test/classes/Config/FormDisplayTest.php
@@ -82,8 +82,8 @@ class FormDisplayTest extends PmaTestCase
         $attrForms->setAccessible(true);
 
         $array = [
-            "Servers" => [
-                "1" => [
+            'Servers' => [
+                '1' => [
                     'test' => 1,
                     1 => ':group:end',
                 ],
@@ -102,8 +102,8 @@ class FormDisplayTest extends PmaTestCase
 
         $this->assertEquals(
             [
-                "Servers/2/test" => "Servers/1/test",
-                "Servers/2/:group:end:0" => "Servers/1/:group:end:0",
+                'Servers/2/test' => 'Servers/1/test',
+                'Servers/2/:group:end:0' => 'Servers/1/:group:end:0',
             ],
             $attrSystemPaths->getValue($this->object)
         );
@@ -113,8 +113,8 @@ class FormDisplayTest extends PmaTestCase
 
         $this->assertEquals(
             [
-                "Servers/2/test" => "Servers-2-test",
-                "Servers/2/:group:end:0" => "Servers-2-:group:end:0",
+                'Servers/2/test' => 'Servers-2-test',
+                'Servers/2/:group:end:0' => 'Servers-2-:group:end:0',
             ],
             $attrTranslatedPaths->getValue($this->object)
         );
@@ -179,15 +179,15 @@ class FormDisplayTest extends PmaTestCase
         );
 
         $arr = [
-            "Servers/1/test" => ['e1'],
-            "foobar" => [
+            'Servers/1/test' => ['e1'],
+            'foobar' => [
                 'e2',
                 'e3',
             ],
         ];
 
         $sysArr = [
-            "Servers/1/test" => "Servers/1/test2",
+            'Servers/1/test' => 'Servers/1/test2',
         ];
 
         $attrSystemPaths = $reflection->getProperty('_systemPaths');
@@ -225,16 +225,16 @@ class FormDisplayTest extends PmaTestCase
         $this->object->fixErrors();
 
         $arr = [
-            "Servers/1/test" => ['e1'],
-            "Servers/2/test" => [
+            'Servers/1/test' => ['e1'],
+            'Servers/2/test' => [
                 'e2',
                 'e3',
             ],
-            "Servers/3/test" => [],
+            'Servers/3/test' => [],
         ];
 
         $sysArr = [
-            "Servers/1/test" => "Servers/1/host",
+            'Servers/1/test' => 'Servers/1/host',
         ];
 
         $attrSystemPaths = $reflection->getProperty('_systemPaths');
@@ -294,7 +294,7 @@ class FormDisplayTest extends PmaTestCase
             )
         );
         $this->assertEquals(
-            "string",
+            'string',
             gettype($value)
         );
 
@@ -358,19 +358,19 @@ class FormDisplayTest extends PmaTestCase
     public function testGetDocLink()
     {
         $this->assertEquals(
-            "./url.php?url=https%3A%2F%2Fdocs.phpmyadmin.net%2Fen%2Flatest%2F" .
-            "config.html%23cfg_Servers_3_test_2_",
-            $this->object->getDocLink("Servers/3/test/2/")
+            './url.php?url=https%3A%2F%2Fdocs.phpmyadmin.net%2Fen%2Flatest%2F' .
+            'config.html%23cfg_Servers_3_test_2_',
+            $this->object->getDocLink('Servers/3/test/2/')
         );
 
         $this->assertEquals(
             '',
-            $this->object->getDocLink("Import")
+            $this->object->getDocLink('Import')
         );
 
         $this->assertEquals(
             '',
-            $this->object->getDocLink("Export")
+            $this->object->getDocLink('Export')
         );
     }
 
@@ -385,13 +385,13 @@ class FormDisplayTest extends PmaTestCase
         $method->setAccessible(true);
 
         $this->assertEquals(
-            "Servers_",
-            $method->invoke($this->object, "Servers/1/")
+            'Servers_',
+            $method->invoke($this->object, 'Servers/1/')
         );
 
         $this->assertEquals(
-            "Servers_23_",
-            $method->invoke($this->object, "Servers/1/23/")
+            'Servers_23_',
+            $method->invoke($this->object, 'Servers/1/23/')
         );
     }
 
@@ -448,12 +448,12 @@ class FormDisplayTest extends PmaTestCase
 
         $expect['comment'] = '';
         if (! function_exists('iconv')) {
-            $expect['values']['iconv'] .= " (unavailable)";
+            $expect['values']['iconv'] .= ' (unavailable)';
             $expect['comment'] = '"iconv" requires iconv extension';
         }
         if (! function_exists('recode_string')) {
-            $expect['values']['recode'] .= " (unavailable)";
-            $expect['comment'] .= ($expect['comment'] ? ", " : '') .
+            $expect['values']['recode'] .= ' (unavailable)';
+            $expect['comment'] .= ($expect['comment'] ? ', ' : '') .
                 '"recode" requires recode extension';
         }
         $expect['comment_warning'] = 1;
@@ -473,11 +473,11 @@ class FormDisplayTest extends PmaTestCase
         );
 
         $comment = '';
-        if (! function_exists("zip_open")) {
+        if (! function_exists('zip_open')) {
             $comment = 'Compressed import will not work due to missing function ' .
                 'zip_open.';
         }
-        if (! function_exists("gzcompress")) {
+        if (! function_exists('gzcompress')) {
             $comment .= ($comment ? '; ' : '') . 'Compressed export will not work ' .
             'due to missing function gzcompress.';
         }
@@ -500,11 +500,11 @@ class FormDisplayTest extends PmaTestCase
         );
 
         $comment = '';
-        if (! function_exists("gzopen")) {
+        if (! function_exists('gzopen')) {
             $comment = 'Compressed import will not work due to missing function ' .
                 'gzopen.';
         }
-        if (! function_exists("gzencode")) {
+        if (! function_exists('gzencode')) {
             $comment .= ($comment ? '; ' : '') . 'Compressed export will not work ' .
             'due to missing function gzencode.';
         }
@@ -527,11 +527,11 @@ class FormDisplayTest extends PmaTestCase
         );
 
         $comment = '';
-        if (! function_exists("bzopen")) {
+        if (! function_exists('bzopen')) {
             $comment = 'Compressed import will not work due to missing function ' .
                 'bzopen.';
         }
-        if (! function_exists("bzcompress")) {
+        if (! function_exists('bzcompress')) {
             $comment .= ($comment ? '; ' : '') . 'Compressed export will not work ' .
             'due to missing function bzcompress.';
         }
@@ -560,7 +560,7 @@ class FormDisplayTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            "maximum 10",
+            'maximum 10',
             $opts['comment']
         );
 
@@ -573,7 +573,7 @@ class FormDisplayTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            "maximum 10",
+            'maximum 10',
             $opts['comment']
         );
 
@@ -586,7 +586,7 @@ class FormDisplayTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            "maximum 10",
+            'maximum 10',
             $opts['comment']
         );
     }
diff --git a/test/classes/Config/FormTest.php b/test/classes/Config/FormTest.php
index fe420d022e..e39a7d8921 100644
--- a/test/classes/Config/FormTest.php
+++ b/test/classes/Config/FormTest.php
@@ -91,16 +91,16 @@ class FormTest extends PmaTestCase
         $attrFieldsTypes->setAccessible(true);
         $attrFieldsTypes->setValue(
             $this->object,
-            ["7" => "Seven"]
+            ['7' => 'Seven']
         );
 
         $this->assertNull(
-            $this->object->getOptionType("123/4/5/6")
+            $this->object->getOptionType('123/4/5/6')
         );
 
         $this->assertEquals(
-            "Seven",
-            $this->object->getOptionType("123/4/5/7")
+            'Seven',
+            $this->object->getOptionType('123/4/5/7')
         );
     }
 
@@ -116,7 +116,7 @@ class FormTest extends PmaTestCase
                 'NHibernate C# DO',
                 'NHibernate XML',
             ],
-            $this->object->getOptionValueList("Export/codegen_format")
+            $this->object->getOptionValueList('Export/codegen_format')
         );
 
         $this->assertEquals(
@@ -125,7 +125,7 @@ class FormTest extends PmaTestCase
                 '1' => 1,
                 '0' => 0,
             ],
-            $this->object->getOptionValueList("OBGzip")
+            $this->object->getOptionValueList('OBGzip')
         );
 
         $this->assertEquals(
@@ -133,9 +133,9 @@ class FormTest extends PmaTestCase
                 'none' => 'Nowhere',
                 'left' => 'Left',
                 'right' => 'Right',
-                'both' =>   "Both",
+                'both' =>   'Both',
             ],
-            $this->object->getOptionValueList("RowActionLinks")
+            $this->object->getOptionValueList('RowActionLinks')
         );
     }
 
@@ -151,8 +151,8 @@ class FormTest extends PmaTestCase
         $method->setAccessible(true);
 
         $array = [
-            "foo" => [
-                "bar" => [
+            'foo' => [
+                'bar' => [
                     'test' => 1,
                     1 => ':group:end',
                 ],
@@ -169,17 +169,17 @@ class FormTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            "pma_form1",
+            'pma_form1',
             $result['pma_form1']
         );
 
         $this->assertEquals(
-            "pma_form2",
+            'pma_form2',
             $result['pma_form2']
         );
 
         $this->assertEquals(
-            "preffoo/foo/bar/test",
+            'preffoo/foo/bar/test',
             $result[0]
         );
 
@@ -203,8 +203,8 @@ class FormTest extends PmaTestCase
         $method->setAccessible(true);
 
         $array = [
-            "foo" => [
-                "bar" => [
+            'foo' => [
+                'bar' => [
                     'test' => 1,
                     1 => ':group:end',
                 ],
@@ -221,7 +221,7 @@ class FormTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            "foo/bar/test",
+            'foo/bar/test',
             $result['test']
         );
 
@@ -233,15 +233,15 @@ class FormTest extends PmaTestCase
         $key = $keys[0];
 
         $this->assertRegExp(
-            "/^\:group\:end\:(\d+)$/",
+            '/^\:group\:end\:(\d+)$/',
             $key
         );
 
-        preg_match("/^\:group\:end\:(\d+)$/", $key, $matches);
+        preg_match('/^\:group\:end\:(\d+)$/', $key, $matches);
         $digit = $matches[1];
 
         $this->assertEquals(
-            "foo/bar/:group:end:" . $digit,
+            'foo/bar/:group:end:' . $digit,
             $result[':group:end:' . $digit]
         );
     }
@@ -258,10 +258,10 @@ class FormTest extends PmaTestCase
         $method->setAccessible(true);
 
         $this->object->fields = [
-            "pma_form1" => "Servers/1/port",
-            "pma_form2" => "Servers/1/auth_type",
-            ":group:end:0" => "preffoo/foo/bar/test",
-            "1" => "preffoo/foo/bar/:group:end:0",
+            'pma_form1' => 'Servers/1/port',
+            'pma_form2' => 'Servers/1/auth_type',
+            ':group:end:0' => 'preffoo/foo/bar/test',
+            '1' => 'preffoo/foo/bar/:group:end:0',
         ];
 
         $attrFieldsTypes = $reflection->getProperty('_fieldsTypes');
@@ -271,10 +271,10 @@ class FormTest extends PmaTestCase
 
         $this->assertEquals(
             [
-                "pma_form1" => "integer",
-                "pma_form2" => "select",
-                ":group:end:0" => "group",
-                "1" => "NULL",
+                'pma_form1' => 'integer',
+                'pma_form2' => 'select',
+                ':group:end:0' => 'group',
+                '1' => 'NULL',
             ],
             $attrFieldsTypes->getValue($this->object)
         );
diff --git a/test/classes/ConfigTest.php b/test/classes/ConfigTest.php
index 2614811257..eacfc40637 100644
--- a/test/classes/ConfigTest.php
+++ b/test/classes/ConfigTest.php
@@ -53,7 +53,7 @@ class ConfigTest extends PmaTestCase
         $GLOBALS['cfg']['ProxyUrl'] = '';
 
         //for testing file permissions
-        $this->permTestObj = new Config(ROOT_PATH . "config.sample.inc.php");
+        $this->permTestObj = new Config(ROOT_PATH . 'config.sample.inc.php');
     }
 
     /**
@@ -96,13 +96,13 @@ class ConfigTest extends PmaTestCase
         $this->object->set('PMA_USR_BROWSER_AGENT', 'IE');
         $this->object->set('PMA_USR_BROWSER_VER', 6);
         $this->object->checkOutputCompression();
-        $this->assertTrue($this->object->get("OBGzip"));
+        $this->assertTrue($this->object->get('OBGzip'));
 
         $this->object->set('OBGzip', 'auto');
         $this->object->set('PMA_USR_BROWSER_AGENT', 'MOZILLA');
         $this->object->set('PMA_USR_BROWSER_VER', 5);
         $this->object->checkOutputCompression();
-        $this->assertTrue($this->object->get("OBGzip"));
+        $this->assertTrue($this->object->get('OBGzip'));
     }
 
     /**
@@ -274,7 +274,7 @@ class ConfigTest extends PmaTestCase
         if (function_exists('gd_info')) {
             $this->object->checkGd2();
             $gd_nfo = gd_info();
-            if (mb_strstr($gd_nfo["GD Version"], '2.')) {
+            if (mb_strstr($gd_nfo['GD Version'], '2.')) {
                 $this->assertEquals(
                     1,
                     $this->object->get('PMA_IS_GD2'),
@@ -339,11 +339,11 @@ class ConfigTest extends PmaTestCase
     {
         return [
             [
-                "Microsoft-IIS 7.0",
+                'Microsoft-IIS 7.0',
                 1,
             ],
             [
-                "Apache/2.2.17",
+                'Apache/2.2.17',
                 0,
             ],
         ];
@@ -452,7 +452,7 @@ class ConfigTest extends PmaTestCase
      */
     public function testGetAndSet()
     {
-        $this->assertNull($this->object->get("unresisting_setting"));
+        $this->assertNull($this->object->get('unresisting_setting'));
 
         $this->object->set('test_setting', 'test_value');
 
@@ -468,14 +468,14 @@ class ConfigTest extends PmaTestCase
     {
         echo $this->object->getSource();
 
-        $this->assertEmpty($this->object->getSource(), "Source is null by default");
+        $this->assertEmpty($this->object->getSource(), 'Source is null by default');
 
-        $this->object->setSource(ROOT_PATH . "config.sample.inc.php");
+        $this->object->setSource(ROOT_PATH . 'config.sample.inc.php');
 
         $this->assertEquals(
-            ROOT_PATH . "config.sample.inc.php",
+            ROOT_PATH . 'config.sample.inc.php',
             $this->object->getSource(),
-            "Cant set new source"
+            'Cant set new source'
         );
     }
 
@@ -812,9 +812,9 @@ class ConfigTest extends PmaTestCase
     public function testSetUserValue()
     {
         $this->object->setUserValue(null, 'lang', 'cs', 'en');
-        $this->object->setUserValue("TEST_COOKIE_USER_VAL", '', 'cfg_val_1');
+        $this->object->setUserValue('TEST_COOKIE_USER_VAL', '', 'cfg_val_1');
         $this->assertEquals(
-            $this->object->getUserValue("TEST_COOKIE_USER_VAL", 'fail'),
+            $this->object->getUserValue('TEST_COOKIE_USER_VAL', 'fail'),
             'cfg_val_1'
         );
     }
@@ -955,7 +955,7 @@ class ConfigTest extends PmaTestCase
     public function testIsGitRevisionLocalGitDir()
     {
         $cwd = getcwd();
-        $test_dir = "gittestdir";
+        $test_dir = 'gittestdir';
 
         unset($_SESSION['git_location']);
         unset($_SESSION['is_git_revision']);
@@ -1016,7 +1016,7 @@ class ConfigTest extends PmaTestCase
     public function testIsGitRevisionExternalGitDir()
     {
         $cwd = getcwd();
-        $test_dir = "gittestdir";
+        $test_dir = 'gittestdir';
 
         unset($_SESSION['git_location']);
         unset($_SESSION['is_git_revision']);
@@ -1078,7 +1078,7 @@ class ConfigTest extends PmaTestCase
     public function testCheckGitRevisionPacksFolder()
     {
         $cwd = getcwd();
-        $test_dir = "gittestdir";
+        $test_dir = 'gittestdir';
 
         unset($_SESSION['git_location']);
         unset($_SESSION['is_git_revision']);
@@ -1123,8 +1123,8 @@ class ConfigTest extends PmaTestCase
             $this->object->get('PMA_VERSION_GIT_BRANCH')
         );
 
-        rmdir(".git/objects/pack");
-        rmdir(".git/objects");
+        rmdir('.git/objects/pack');
+        rmdir('.git/objects');
         unlink('.git/packed-refs');
         unlink('.git/HEAD');
         unlink('.git/config');
@@ -1143,7 +1143,7 @@ class ConfigTest extends PmaTestCase
     public function testCheckGitRevisionRefFile()
     {
         $cwd = getcwd();
-        $test_dir = "gittestdir";
+        $test_dir = 'gittestdir';
 
         unset($_SESSION['git_location']);
         unset($_SESSION['is_git_revision']);
@@ -1180,8 +1180,8 @@ class ConfigTest extends PmaTestCase
         rmdir('.git/refs/remotes/origin');
         rmdir('.git/refs/remotes');
         rmdir('.git/refs');
-        rmdir(".git/objects/pack");
-        rmdir(".git/objects");
+        rmdir('.git/objects/pack');
+        rmdir('.git/objects');
         unlink('.git/HEAD');
         unlink('.git/config');
         rmdir('.git');
@@ -1199,7 +1199,7 @@ class ConfigTest extends PmaTestCase
     public function testCheckGitRevisionPacksFile()
     {
         $cwd = getcwd();
-        $test_dir = "gittestdir";
+        $test_dir = 'gittestdir';
 
         unset($_SESSION['git_location']);
         unset($_SESSION['is_git_revision']);
@@ -1253,9 +1253,9 @@ class ConfigTest extends PmaTestCase
             $this->object->get('PMA_VERSION_GIT_BRANCH')
         );
 
-        unlink(".git/objects/info/packs");
-        rmdir(".git/objects/info");
-        rmdir(".git/objects");
+        unlink('.git/objects/info/packs');
+        rmdir('.git/objects/info');
+        rmdir('.git/objects');
         unlink('.git/packed-refs');
         unlink('.git/HEAD');
         unlink('.git/config');
diff --git a/test/classes/Controllers/Database/StructureControllerTest.php b/test/classes/Controllers/Database/StructureControllerTest.php
index 26e0515cbb..2c80e98be6 100644
--- a/test/classes/Controllers/Database/StructureControllerTest.php
+++ b/test/classes/Controllers/Database/StructureControllerTest.php
@@ -59,7 +59,7 @@ class StructureControllerTest extends PmaTestCase
     {
         $GLOBALS['server'] = 1;
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
-        $GLOBALS['table'] = "table";
+        $GLOBALS['table'] = 'table';
         $GLOBALS['db'] = 'db';
         $GLOBALS['PMA_PHP_SELF'] = 'index.php';
         $GLOBALS['replication_info']['master']['status'] = false;
diff --git a/test/classes/Controllers/Server/DatabasesControllerTest.php b/test/classes/Controllers/Server/DatabasesControllerTest.php
index f3c6502842..0d5134df52 100644
--- a/test/classes/Controllers/Server/DatabasesControllerTest.php
+++ b/test/classes/Controllers/Server/DatabasesControllerTest.php
@@ -38,7 +38,7 @@ class DatabasesControllerTest extends TestCase
         $GLOBALS['PMA_PHP_SELF'] = 'index.php';
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
         $GLOBALS['pmaThemeImage'] = 'image';
-        $GLOBALS['text_dir'] = "text_dir";
+        $GLOBALS['text_dir'] = 'text_dir';
     }
 
     /**
diff --git a/test/classes/Controllers/Server/Status/AdvisorControllerTest.php b/test/classes/Controllers/Server/Status/AdvisorControllerTest.php
index d93ab7d734..e5ca1e44db 100644
--- a/test/classes/Controllers/Server/Status/AdvisorControllerTest.php
+++ b/test/classes/Controllers/Server/Status/AdvisorControllerTest.php
@@ -79,7 +79,7 @@ class AdvisorControllerTest extends TestCase
             ],
             [
                 "SELECT concat('Com_', variable_name), variable_value "
-                . "FROM data_dictionary.GLOBAL_STATEMENTS",
+                . 'FROM data_dictionary.GLOBAL_STATEMENTS',
                 0,
                 1,
                 DatabaseInterface::CONNECT_USER,
diff --git a/test/classes/Controllers/Server/Status/MonitorControllerTest.php b/test/classes/Controllers/Server/Status/MonitorControllerTest.php
index 7319640e40..43974d045f 100644
--- a/test/classes/Controllers/Server/Status/MonitorControllerTest.php
+++ b/test/classes/Controllers/Server/Status/MonitorControllerTest.php
@@ -49,25 +49,25 @@ class MonitorControllerTest extends TestCase
         $GLOBALS['pmaThemeImage'] = '';
 
         $serverStatus = [
-            "Aborted_clients" => "0",
-            "Aborted_connects" => "0",
-            "Com_delete_multi" => "0",
-            "Com_create_function" => "0",
-            "Com_empty_query" => "0",
+            'Aborted_clients' => '0',
+            'Aborted_connects' => '0',
+            'Com_delete_multi' => '0',
+            'Com_create_function' => '0',
+            'Com_empty_query' => '0',
         ];
 
         $serverVariables = [
-            "auto_increment_increment" => "1",
-            "auto_increment_offset" => "1",
-            "automatic_sp_privileges" => "ON",
-            "back_log" => "50",
-            "big_tables" => "OFF",
-            "version" => "8.0.2",
+            'auto_increment_increment' => '1',
+            'auto_increment_offset' => '1',
+            'automatic_sp_privileges' => 'ON',
+            'back_log' => '50',
+            'big_tables' => 'OFF',
+            'version' => '8.0.2',
         ];
 
         $fetchResult = [
             [
-                "SHOW GLOBAL STATUS",
+                'SHOW GLOBAL STATUS',
                 0,
                 1,
                 DatabaseInterface::CONNECT_USER,
@@ -75,7 +75,7 @@ class MonitorControllerTest extends TestCase
                 $serverStatus,
             ],
             [
-                "SHOW GLOBAL VARIABLES",
+                'SHOW GLOBAL VARIABLES',
                 0,
                 1,
                 DatabaseInterface::CONNECT_USER,
@@ -84,7 +84,7 @@ class MonitorControllerTest extends TestCase
             ],
             [
                 "SELECT concat('Com_', variable_name), variable_value "
-                . "FROM data_dictionary.GLOBAL_STATEMENTS",
+                . 'FROM data_dictionary.GLOBAL_STATEMENTS',
                 0,
                 1,
                 DatabaseInterface::CONNECT_USER,
diff --git a/test/classes/Controllers/Server/Status/ProcessesControllerTest.php b/test/classes/Controllers/Server/Status/ProcessesControllerTest.php
index 3db8dab61d..bce58df9f5 100644
--- a/test/classes/Controllers/Server/Status/ProcessesControllerTest.php
+++ b/test/classes/Controllers/Server/Status/ProcessesControllerTest.php
@@ -81,7 +81,7 @@ class ProcessesControllerTest extends TestCase
             ],
             [
                 "SELECT concat('Com_', variable_name), variable_value "
-                . "FROM data_dictionary.GLOBAL_STATEMENTS",
+                . 'FROM data_dictionary.GLOBAL_STATEMENTS',
                 0,
                 1,
                 DatabaseInterface::CONNECT_USER,
diff --git a/test/classes/Controllers/Server/Status/QueriesControllerTest.php b/test/classes/Controllers/Server/Status/QueriesControllerTest.php
index f7a38cd70d..1e98320a00 100644
--- a/test/classes/Controllers/Server/Status/QueriesControllerTest.php
+++ b/test/classes/Controllers/Server/Status/QueriesControllerTest.php
@@ -81,7 +81,7 @@ class QueriesControllerTest extends TestCase
             ],
             [
                 "SELECT concat('Com_', variable_name), variable_value "
-                . "FROM data_dictionary.GLOBAL_STATEMENTS",
+                . 'FROM data_dictionary.GLOBAL_STATEMENTS',
                 0,
                 1,
                 DatabaseInterface::CONNECT_USER,
diff --git a/test/classes/Controllers/Server/Status/StatusControllerTest.php b/test/classes/Controllers/Server/Status/StatusControllerTest.php
index 88badc984b..866a720f8f 100644
--- a/test/classes/Controllers/Server/Status/StatusControllerTest.php
+++ b/test/classes/Controllers/Server/Status/StatusControllerTest.php
@@ -79,7 +79,7 @@ class StatusControllerTest extends TestCase
             ],
             [
                 "SELECT concat('Com_', variable_name), variable_value "
-                . "FROM data_dictionary.GLOBAL_STATEMENTS",
+                . 'FROM data_dictionary.GLOBAL_STATEMENTS',
                 0,
                 1,
                 DatabaseInterface::CONNECT_USER,
diff --git a/test/classes/Controllers/Server/Status/VariablesControllerTest.php b/test/classes/Controllers/Server/Status/VariablesControllerTest.php
index 71cbfa2247..39ad09a596 100644
--- a/test/classes/Controllers/Server/Status/VariablesControllerTest.php
+++ b/test/classes/Controllers/Server/Status/VariablesControllerTest.php
@@ -80,7 +80,7 @@ class VariablesControllerTest extends TestCase
             ],
             [
                 "SELECT concat('Com_', variable_name), variable_value "
-                . "FROM data_dictionary.GLOBAL_STATEMENTS",
+                . 'FROM data_dictionary.GLOBAL_STATEMENTS',
                 0,
                 1,
                 DatabaseInterface::CONNECT_USER,
diff --git a/test/classes/Controllers/Server/VariablesControllerTest.php b/test/classes/Controllers/Server/VariablesControllerTest.php
index 28a6de27b4..dafef28964 100644
--- a/test/classes/Controllers/Server/VariablesControllerTest.php
+++ b/test/classes/Controllers/Server/VariablesControllerTest.php
@@ -123,13 +123,13 @@ class VariablesControllerTest extends TestCase
             $html
         );
 
-        $name = "auto_increment_increment";
+        $name = 'auto_increment_increment';
         $value = htmlspecialchars(str_replace('_', ' ', $name));
         $this->assertStringContainsString(
             $value,
             $html
         );
-        $name = "auto_increment_offset";
+        $name = 'auto_increment_offset';
         $value = htmlspecialchars(str_replace('_', ' ', $name));
         $this->assertStringContainsString(
             $value,
diff --git a/test/classes/Controllers/Table/IndexesControllerTest.php b/test/classes/Controllers/Table/IndexesControllerTest.php
index 91152bb27b..d299877144 100644
--- a/test/classes/Controllers/Table/IndexesControllerTest.php
+++ b/test/classes/Controllers/Table/IndexesControllerTest.php
@@ -53,19 +53,19 @@ class IndexesControllerTest extends PmaTestCase
 
         $indexs = [
             [
-                "Schema" => "Schema1",
-                "Key_name" => "Key_name1",
-                "Column_name" => "Column_name1",
+                'Schema' => 'Schema1',
+                'Key_name' => 'Key_name1',
+                'Column_name' => 'Column_name1',
             ],
             [
-                "Schema" => "Schema2",
-                "Key_name" => "Key_name2",
-                "Column_name" => "Column_name2",
+                'Schema' => 'Schema2',
+                'Key_name' => 'Key_name2',
+                'Column_name' => 'Column_name2',
             ],
             [
-                "Schema" => "Schema3",
-                "Key_name" => "Key_name3",
-                "Column_name" => "Column_name3",
+                'Schema' => 'Schema3',
+                'Key_name' => 'Key_name3',
+                'Column_name' => 'Column_name3',
             ],
         ];
 
@@ -140,11 +140,11 @@ class IndexesControllerTest extends PmaTestCase
             ->disableOriginalConstructor()
             ->getMock();
         $table->expects($this->any())->method('getStatusInfo')
-            ->will($this->returnValue(""));
+            ->will($this->returnValue(''));
         $table->expects($this->any())->method('isView')
             ->will($this->returnValue(false));
         $table->expects($this->any())->method('getNameAndTypeOfTheColumns')
-            ->will($this->returnValue(["field_name" => "field_type"]));
+            ->will($this->returnValue(['field_name' => 'field_type']));
 
         $GLOBALS['dbi']->expects($this->any())->method('getTable')
             ->will($this->returnValue($table));
@@ -209,11 +209,11 @@ class IndexesControllerTest extends PmaTestCase
 
         //$field_name & $field_type
         $this->assertStringContainsString(
-            "field_name",
+            'field_name',
             $html
         );
         $this->assertStringContainsString(
-            "field_type",
+            'field_type',
             $html
         );
     }
diff --git a/test/classes/Controllers/Table/SearchControllerTest.php b/test/classes/Controllers/Table/SearchControllerTest.php
index 27cc85ac30..911f66eb79 100644
--- a/test/classes/Controllers/Table/SearchControllerTest.php
+++ b/test/classes/Controllers/Table/SearchControllerTest.php
@@ -123,15 +123,15 @@ class SearchControllerTest extends PmaTestCase
             $this->template,
             $GLOBALS['db'],
             $GLOBALS['table'],
-            "zoom",
+            'zoom',
             null,
             new Relation($GLOBALS['dbi'], $this->template)
         );
         $columnIndex = 0;
-        $find = "Field";
-        $replaceWith = "Column";
+        $find = 'Field';
+        $replaceWith = 'Column';
         $useRegex = false;
-        $charSet = "UTF-8";
+        $charSet = 'UTF-8';
         $tableSearch->replace(
             $columnIndex,
             $find,
@@ -141,7 +141,7 @@ class SearchControllerTest extends PmaTestCase
         );
 
         $sql_query = $GLOBALS['sql_query'];
-        $result = "UPDATE `PMA_BookMark` SET `Field1` = "
+        $result = 'UPDATE `PMA_BookMark` SET `Field1` = '
             . "REPLACE(`Field1`, 'Field', 'Column') "
             . "WHERE `Field1` LIKE '%Field%' COLLATE UTF-8_bin";
         $this->assertEquals(
@@ -159,9 +159,9 @@ class SearchControllerTest extends PmaTestCase
     {
         $_POST['distinct'] = true;
         $_POST['zoom_submit'] = true;
-        $_POST['table'] = "PMA";
-        $_POST['orderByColumn'] = "name";
-        $_POST['order'] = "asc";
+        $_POST['table'] = 'PMA';
+        $_POST['orderByColumn'] = 'name';
+        $_POST['order'] = 'asc';
         $_POST['customWhereClause'] = "name='pma'";
 
         $class = new ReflectionClass(SearchController::class);
@@ -173,14 +173,14 @@ class SearchControllerTest extends PmaTestCase
             $this->template,
             $GLOBALS['db'],
             $GLOBALS['table'],
-            "zoom",
+            'zoom',
             null,
             new Relation($GLOBALS['dbi'], $this->template)
         );
 
         $sql = $method->invoke($tableSearch);
         $result = "SELECT DISTINCT *  FROM `PMA` WHERE name='pma' "
-            . "ORDER BY `name` asc";
+            . 'ORDER BY `name` asc';
 
         $this->assertEquals(
             $result,
@@ -189,7 +189,7 @@ class SearchControllerTest extends PmaTestCase
 
         unset($_POST['customWhereClause']);
         $sql = $method->invoke($tableSearch);
-        $result = "SELECT DISTINCT *  FROM `PMA` ORDER BY `name` asc";
+        $result = 'SELECT DISTINCT *  FROM `PMA` ORDER BY `name` asc';
         $this->assertEquals(
             $result,
             $sql
@@ -223,29 +223,29 @@ class SearchControllerTest extends PmaTestCase
             'type4',
         ];
         $_POST['criteriaColumnCollations'] = [
-            "char1",
-            "char2",
-            "char3",
-            "char4",
-            "char5",
-            "char6",
-            "char7",
+            'char1',
+            'char2',
+            'char3',
+            'char4',
+            'char5',
+            'char6',
+            'char7',
         ];
         $_POST['criteriaColumnOperators'] = [
-            "!=",
-            ">",
-            "IS NULL",
-            "LIKE %...%",
-            "REGEXP ^...$",
-            "IN (...)",
-            "BETWEEN",
+            '!=',
+            '>',
+            'IS NULL',
+            'LIKE %...%',
+            'REGEXP ^...$',
+            'IN (...)',
+            'BETWEEN',
         ];
 
         $sql = $method->invoke($tableSearch);
         $result = "SELECT DISTINCT *  FROM `PMA` WHERE `name` != 'value1'"
             . " AND `id` > value2 AND `index` IS NULL AND `index2` LIKE '%value4%'"
-            . " AND `index3` REGEXP ^value5$ AND `index4` IN (value6) AND `index5`"
-            . " BETWEEN value7 AND value8 ORDER BY `name` asc";
+            . ' AND `index3` REGEXP ^value5$ AND `index4` IN (value6) AND `index5`'
+            . ' BETWEEN value7 AND value8 ORDER BY `name` asc';
         $this->assertEquals(
             $result,
             $sql
diff --git a/test/classes/Controllers/Table/StructureControllerTest.php b/test/classes/Controllers/Table/StructureControllerTest.php
index 813e7b75cf..3b26fe70f9 100644
--- a/test/classes/Controllers/Table/StructureControllerTest.php
+++ b/test/classes/Controllers/Table/StructureControllerTest.php
@@ -304,12 +304,12 @@ class StructureControllerTest extends PmaTestCase
             new CreateAddField($GLOBALS['dbi'])
         );
 
-        $submit_mult = "index";
-        $db = "PMA_db";
-        $table = "PMA_table";
+        $submit_mult = 'index';
+        $db = 'PMA_db';
+        $table = 'PMA_table';
         $selected = [
-            "table1",
-            "table2",
+            'table1',
+            'table2',
         ];
         $action = 'db_delete_row';
         $containerBuilder = new ContainerBuilder();
@@ -355,7 +355,7 @@ class StructureControllerTest extends PmaTestCase
             $centralColsError
         );
 
-        $submit_mult = "unique";
+        $submit_mult = 'unique';
 
         list($what, $query_type, $is_unset_submit_mult, $mult_btn, $centralColsError)
             = $method->invokeArgs(
diff --git a/test/classes/CoreTest.php b/test/classes/CoreTest.php
index 41420fef2c..e7686bf401 100644
--- a/test/classes/CoreTest.php
+++ b/test/classes/CoreTest.php
@@ -46,14 +46,14 @@ class CoreTest extends PmaTestCase
     public function testArrayRead()
     {
         $arr = [
-            "int" => 1,
-            "str" => "str_val",
-            "arr" => [
+            'int' => 1,
+            'str' => 'str_val',
+            'arr' => [
                 'val1',
                 'val2',
                 'val3',
             ],
-            "sarr" => [
+            'sarr' => [
                 'arr1' => [
                     1,
                     2,
@@ -149,14 +149,14 @@ class CoreTest extends PmaTestCase
     public function testArrayWrite()
     {
         $arr = [
-            "int" => 1,
-            "str" => "str_val",
-            "arr" => [
+            'int' => 1,
+            'str' => 'str_val',
+            'arr' => [
                 'val1',
                 'val2',
                 'val3',
             ],
-            "sarr" => [
+            'sarr' => [
                 'arr1' => [
                     1,
                     2,
@@ -218,14 +218,14 @@ class CoreTest extends PmaTestCase
     public function testArrayRemove()
     {
         $arr = [
-            "int" => 1,
-            "str" => "str_val",
-            "arr" => [
+            'int' => 1,
+            'str' => 'str_val',
+            'arr' => [
                 'val1',
                 'val2',
                 'val3',
             ],
-            "sarr" => [
+            'sarr' => [
                 'arr1' => [
                     1,
                     2,
@@ -453,8 +453,8 @@ class CoreTest extends PmaTestCase
      */
     public function testFatalErrorMessage()
     {
-        $this->expectOutputRegex("/FatalError!/");
-        Core::fatalError("FatalError!");
+        $this->expectOutputRegex('/FatalError!/');
+        Core::fatalError('FatalError!');
     }
 
     /**
@@ -464,19 +464,19 @@ class CoreTest extends PmaTestCase
      */
     public function testFatalErrorMessageWithArgs()
     {
-        $message = "Fatal error #%d in file %s.";
+        $message = 'Fatal error #%d in file %s.';
         $params = [
             1,
             'error_file.php',
         ];
 
-        $this->expectOutputRegex("/Fatal error #1 in file error_file.php./");
+        $this->expectOutputRegex('/Fatal error #1 in file error_file.php./');
         Core::fatalError($message, $params);
 
-        $message = "Fatal error in file %s.";
+        $message = 'Fatal error in file %s.';
         $params = 'error_file.php';
 
-        $this->expectOutputRegex("/Fatal error in file error_file.php./");
+        $this->expectOutputRegex('/Fatal error in file error_file.php./');
         Core::fatalError($message, $params);
     }
 
@@ -659,12 +659,12 @@ class CoreTest extends PmaTestCase
     <meta http-equiv=\"expires\" content=\"0\">"
             . "\n    <meta http-equiv=\"Pragma\" content=\"no-cache\">"
             . "\n    <meta http-equiv=\"Cache-Control\" content=\"no-cache\">"
-            . "\n    <meta http-equiv=\"Refresh\" content=\"0;url=" . $testUri_html . "\">"
+            . "\n    <meta http-equiv=\"Refresh\" content=\"0;url=" . $testUri_html . '">'
             . "\n    <script type=\"text/javascript\">\n        //<![CDATA[
         setTimeout(function() { window.location = decodeURI('" . $testUri_js . "'); }, 2000);
         //]]>\n    </script>\n</head>
 <body>\n<script type=\"text/javascript\">\n    //<![CDATA[
-    document.write('<p><a href=\"" . $testUri_html . "\">" . __('Go') . "</a></p>');
+    document.write('<p><a href=\"" . $testUri_html . '">' . __('Go') . "</a></p>');
     //]]>\n</script>\n</body>\n</html>
 ";
 
@@ -1158,7 +1158,7 @@ class CoreTest extends PmaTestCase
             ],
             [
                 'string',
-                "string",
+                'string',
             ],
             [
                 [
diff --git a/test/classes/Database/Designer/CommonTest.php b/test/classes/Database/Designer/CommonTest.php
index 5a55f562cb..a6518dfd9c 100644
--- a/test/classes/Database/Designer/CommonTest.php
+++ b/test/classes/Database/Designer/CommonTest.php
@@ -104,8 +104,8 @@ class CommonTest extends TestCase
         $dbi->expects($this->once())
             ->method('fetchResult')
             ->with(
-                "SELECT `page_descr` FROM `pmadb`.`pdf_pages`"
-                . " WHERE `page_nr` = " . $pg,
+                'SELECT `page_descr` FROM `pmadb`.`pdf_pages`'
+                . ' WHERE `page_nr` = ' . $pg,
                 null,
                 null,
                 DatabaseInterface::CONNECT_CONTROL,
@@ -168,7 +168,7 @@ class CommonTest extends TestCase
         $dbi->expects($this->once())
             ->method('fetchResult')
             ->with(
-                "SELECT `page_nr` FROM `pmadb`.`pdf_pages`"
+                'SELECT `page_nr` FROM `pmadb`.`pdf_pages`'
                 . " WHERE `db_name` = '" . $db . "'"
                 . " AND `page_descr` = '" . $db . "'",
                 null,
@@ -203,7 +203,7 @@ class CommonTest extends TestCase
         $dbi->expects($this->once())
             ->method('fetchResult')
             ->with(
-                "SELECT `page_nr` FROM `pmadb`.`pdf_pages`"
+                'SELECT `page_nr` FROM `pmadb`.`pdf_pages`'
                 . " WHERE `db_name` = '" . $db . "'"
                 . " AND `page_descr` = '" . $db . "'",
                 null,
@@ -239,7 +239,7 @@ class CommonTest extends TestCase
         $dbi->expects($this->once())
             ->method('fetchResult')
             ->with(
-                "SELECT `page_nr` FROM `pmadb`.`pdf_pages`"
+                'SELECT `page_nr` FROM `pmadb`.`pdf_pages`'
                 . " WHERE `db_name` = '" . $db . "'"
                 . " AND `page_descr` = '" . $db . "'",
                 null,
diff --git a/test/classes/Database/DesignerTest.php b/test/classes/Database/DesignerTest.php
index 78e3526f96..75754a7137 100644
--- a/test/classes/Database/DesignerTest.php
+++ b/test/classes/Database/DesignerTest.php
@@ -73,7 +73,7 @@ class DesignerTest extends TestCase
         $dbi->expects($this->once())
             ->method('tryQuery')
             ->with(
-                "SELECT `page_nr`, `page_descr` FROM `pmadb`.`pdf_pages`"
+                'SELECT `page_nr`, `page_descr` FROM `pmadb`.`pdf_pages`'
                 . " WHERE db_name = '" . $db . "' ORDER BY `page_descr`",
                 DatabaseInterface::CONNECT_CONTROL,
                 DatabaseInterface::QUERY_STORE,
diff --git a/test/classes/DatabaseInterfaceTest.php b/test/classes/DatabaseInterfaceTest.php
index 7e37fbf75a..870fd0624a 100644
--- a/test/classes/DatabaseInterfaceTest.php
+++ b/test/classes/DatabaseInterfaceTest.php
@@ -121,12 +121,12 @@ class DatabaseInterfaceTest extends PmaTestCase
             ->will($this->returnValue(true));
 
         $meta1 = new stdClass();
-        $meta1->table = "meta1_table";
-        $meta1->name = "meta1_name";
+        $meta1->table = 'meta1_table';
+        $meta1->name = 'meta1_name';
 
         $meta2 = new stdClass();
-        $meta2->table = "meta2_table";
-        $meta2->name = "meta2_name";
+        $meta2->table = 'meta2_table';
+        $meta2->name = 'meta2_name';
 
         $extension->expects($this->any())
             ->method('getFieldsMeta')
@@ -141,10 +141,10 @@ class DatabaseInterfaceTest extends PmaTestCase
 
         $dbi = new DatabaseInterface($extension);
 
-        $sql_query = "PMA_sql_query";
+        $sql_query = 'PMA_sql_query';
         $view_columns = [
-            "view_columns1",
-            "view_columns2",
+            'view_columns1',
+            'view_columns2',
         ];
 
         $column_map = $dbi->getColumnMapFromSql(
@@ -208,7 +208,7 @@ class DatabaseInterfaceTest extends PmaTestCase
         // test case for system schema
         $this->assertEquals(
             'utf8_general_ci',
-            $this->_dbi->getDbCollation("information_schema")
+            $this->_dbi->getDbCollation('information_schema')
         );
 
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
diff --git a/test/classes/Display/ChangePasswordTest.php b/test/classes/Display/ChangePasswordTest.php
index 4540b3f29e..b9f966be49 100644
--- a/test/classes/Display/ChangePasswordTest.php
+++ b/test/classes/Display/ChangePasswordTest.php
@@ -36,12 +36,12 @@ class ChangePasswordTest extends TestCase
         $GLOBALS['PMA_Config'] = new Config();
         $GLOBALS['PMA_Config']->enableBc();
         $GLOBALS['cfg']['MaxRows'] = 10;
-        $GLOBALS['cfg']['ServerDefault'] = "PMA_server";
+        $GLOBALS['cfg']['ServerDefault'] = 'PMA_server';
         $GLOBALS['cfg']['TableNavigationLinksMode'] = 'icons';
         $GLOBALS['cfg']['LimitChars'] = 100;
         $GLOBALS['cfg']['ActionLinksMode'] = 'icons';
-        $GLOBALS['cfg']['Server']['host'] = "localhost";
-        $GLOBALS['cfg']['Server']['user'] = "pma_user";
+        $GLOBALS['cfg']['Server']['host'] = 'localhost';
+        $GLOBALS['cfg']['Server']['user'] = 'pma_user';
         $GLOBALS['cfg']['ShowHint'] = true;
         $GLOBALS['cfg']['ActionLinksMode'] = 'icons';
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
@@ -49,7 +49,7 @@ class ChangePasswordTest extends TestCase
         $GLOBALS['server'] = 0;
 
         //$_SESSION
-        $_SESSION['relation'][$GLOBALS['server']] = "relation";
+        $_SESSION['relation'][$GLOBALS['server']] = 'relation';
     }
 
     /**
@@ -59,8 +59,8 @@ class ChangePasswordTest extends TestCase
      */
     public function testGetHtml()
     {
-        $username = "pma_username";
-        $hostname = "pma_hostname";
+        $username = 'pma_username';
+        $hostname = 'pma_hostname';
         $_REQUEST['route'] = '/server/privileges';
 
         //Call the test function
diff --git a/test/classes/Display/CreateTableTest.php b/test/classes/Display/CreateTableTest.php
index 7e1060f42f..f962a376d8 100644
--- a/test/classes/Display/CreateTableTest.php
+++ b/test/classes/Display/CreateTableTest.php
@@ -36,18 +36,18 @@ class CreateTableTest extends TestCase
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
         $GLOBALS['cfg']['DBG']['sql'] = false;
         $GLOBALS['cfg']['MaxRows'] = 10;
-        $GLOBALS['cfg']['ServerDefault'] = "PMA_server";
+        $GLOBALS['cfg']['ServerDefault'] = 'PMA_server';
         $GLOBALS['cfg']['TableNavigationLinksMode'] = 'icons';
         $GLOBALS['cfg']['LimitChars'] = 100;
         $GLOBALS['cfg']['ActionLinksMode'] = 'icons';
-        $GLOBALS['cfg']['Server']['host'] = "localhost";
-        $GLOBALS['cfg']['Server']['user'] = "pma_user";
+        $GLOBALS['cfg']['Server']['host'] = 'localhost';
+        $GLOBALS['cfg']['Server']['user'] = 'pma_user';
         $GLOBALS['cfg']['ShowHint'] = true;
         $GLOBALS['cfg']['ActionLinksMode'] = 'icons';
         $GLOBALS['PMA_PHP_SELF'] = Url::getFromRoute('/server/privileges');
 
         //$_SESSION
-        $_SESSION['relation'][$GLOBALS['server']] = "relation";
+        $_SESSION['relation'][$GLOBALS['server']] = 'relation';
     }
 
     /**
@@ -57,7 +57,7 @@ class CreateTableTest extends TestCase
      */
     public function testPMAGetHtmlForCreateTable()
     {
-        $db = "pma_db";
+        $db = 'pma_db';
 
         //Call the test function
         $html = CreateTable::getHtml($db);
diff --git a/test/classes/Display/ExportTest.php b/test/classes/Display/ExportTest.php
index 53a1c0e9fe..768a7e58a2 100644
--- a/test/classes/Display/ExportTest.php
+++ b/test/classes/Display/ExportTest.php
@@ -35,15 +35,15 @@ class ExportTest extends TestCase
     {
         $GLOBALS['PMA_Config'] = new Config();
         $GLOBALS['PMA_Config']->enableBc();
-        $GLOBALS['cfg']['Server']['host'] = "localhost";
-        $GLOBALS['cfg']['Server']['user'] = "pma_user";
+        $GLOBALS['cfg']['Server']['host'] = 'localhost';
+        $GLOBALS['cfg']['Server']['user'] = 'pma_user';
         $GLOBALS['server'] = 0;
 
-        $GLOBALS['table'] = "table";
-        $GLOBALS['db'] = "PMA";
+        $GLOBALS['table'] = 'table';
+        $GLOBALS['db'] = 'PMA';
 
         //$_SESSION
-        $_SESSION['relation'][$GLOBALS['server']] = "";
+        $_SESSION['relation'][$GLOBALS['server']] = '';
 
         $pmaconfig = $this->getMockBuilder('PhpMyAdmin\Config')
             ->disableOriginalConstructor()
@@ -65,11 +65,11 @@ class ExportTest extends TestCase
      */
     public function testGetHtmlForHiddenInputs()
     {
-        $export_type = "server";
-        $db = "PMA";
-        $table = "PMA_test";
-        $single_table_str = "PMA_single_str";
-        $sql_query_str = "sql_query_str";
+        $export_type = 'server';
+        $db = 'PMA';
+        $table = 'PMA_test';
+        $single_table_str = 'PMA_single_str';
+        $sql_query_str = 'sql_query_str';
 
         //Call the test function
         $html = $this->export->getHtmlForHiddenInputs(
@@ -105,15 +105,15 @@ class ExportTest extends TestCase
     public function testGetHtmlForOptions()
     {
         global $cfg;
-        $cfg['Export']['method'] = "XML";
-        $cfg['SaveDir'] = "/tmp";
+        $cfg['Export']['method'] = 'XML';
+        $cfg['SaveDir'] = '/tmp';
 
-        $export_type = "server";
-        $db = "PMA";
-        $table = "PMA_test";
-        $multi_values_str = "multi_values_str";
-        $num_tables_str = "10";
-        $unlim_num_rows_str = "unlim_num_rows_str";
+        $export_type = 'server';
+        $db = 'PMA';
+        $table = 'PMA_test';
+        $multi_values_str = 'multi_values_str';
+        $num_tables_str = '10';
+        $unlim_num_rows_str = 'unlim_num_rows_str';
         //$single_table = "single_table";
         $GLOBALS['dbi']->cacheTableContent([$db, $table, 'ENGINE'], 'MERGE');
 
@@ -138,7 +138,7 @@ class ExportTest extends TestCase
 
         /* Scan for plugins */
         $export_list = Plugins::getPlugins(
-            "export",
+            'export',
             'libraries/classes/Plugins/Export/',
             [
                 'export_type' => $export_type,
diff --git a/test/classes/EncodingTest.php b/test/classes/EncodingTest.php
index 2a2fce8681..411c65caa0 100644
--- a/test/classes/EncodingTest.php
+++ b/test/classes/EncodingTest.php
@@ -190,7 +190,7 @@ class EncodingTest extends TestCase
      */
     public function testFileConv()
     {
-        $file_str = "教育漢字常用漢字";
+        $file_str = '教育漢字常用漢字';
         $filename = 'test.kanji';
         $file = fopen($filename, 'w');
         fwrite($file, $file_str);
diff --git a/test/classes/EnvironmentTest.php b/test/classes/EnvironmentTest.php
index 2c8c774d84..6e9a30c960 100644
--- a/test/classes/EnvironmentTest.php
+++ b/test/classes/EnvironmentTest.php
@@ -41,29 +41,29 @@ class EnvironmentTest extends TestCase
     {
         try {
             $pdo = new PDO(
-                "mysql:host=" . $GLOBALS['TESTSUITE_SERVER'] . ";port=" . $GLOBALS['TESTSUITE_PORT'],
+                'mysql:host=' . $GLOBALS['TESTSUITE_SERVER'] . ';port=' . $GLOBALS['TESTSUITE_PORT'],
                 $GLOBALS['TESTSUITE_USER'],
                 $GLOBALS['TESTSUITE_PASSWORD']
             );
             $this->assertNull(
                 $pdo->errorCode(),
-                "Error when trying to connect to database"
+                'Error when trying to connect to database'
             );
 
-            $pdo->exec("SHOW DATABASES;");
+            $pdo->exec('SHOW DATABASES;');
             $this->assertEquals(
                 0,
                 $pdo->errorCode(),
                 'Error trying to show tables for database'
             );
         } catch (Exception $e) {
-            $this->markTestSkipped("Error: " . $e->getMessage());
+            $this->markTestSkipped('Error: ' . $e->getMessage());
         }
 
         // Check id MySQL server is 5 version
         preg_match(
-            "/^(\d+)?\.(\d+)?\.(\*|\d+)/",
-            $pdo->getAttribute(constant("PDO::ATTR_SERVER_VERSION")),
+            '/^(\d+)?\.(\d+)?\.(\*|\d+)/',
+            $pdo->getAttribute(constant('PDO::ATTR_SERVER_VERSION')),
             $version_parts
         );
         $this->assertEquals(5, $version_parts[1]);
diff --git a/test/classes/ErrorReportTest.php b/test/classes/ErrorReportTest.php
index dbbf6883f8..478bfb450d 100644
--- a/test/classes/ErrorReportTest.php
+++ b/test/classes/ErrorReportTest.php
@@ -132,10 +132,10 @@ class ErrorReportTest extends TestCase
             ->method('create')
             ->with(
                 $submissionUrl,
-                "POST",
+                'POST',
                 false,
                 json_encode($report),
-                "Content-Type: application/json"
+                'Content-Type: application/json'
             )
             ->willReturn($return);
 
diff --git a/test/classes/FontTest.php b/test/classes/FontTest.php
index a1bda75ef8..f70f01f84c 100644
--- a/test/classes/FontTest.php
+++ b/test/classes/FontTest.php
@@ -43,115 +43,115 @@ class FontTest extends PmaTestCase
         // empty string
         $this->assertEquals(
             0,
-            $this->font->getStringWidth("", "arial", 10)
+            $this->font->getStringWidth('', 'arial', 10)
         );
 
         // empty string
         $this->assertEquals(
             3,
-            $this->font->getStringWidth(" ", "arial", 10)
+            $this->font->getStringWidth(' ', 'arial', 10)
         );
 
         // string "a"
         $this->assertEquals(
             6,
-            $this->font->getStringWidth("a", "arial", 10)
+            $this->font->getStringWidth('a', 'arial', 10)
         );
 
         // string "aa"
         $this->assertEquals(
             12,
-            $this->font->getStringWidth("aa", "arial", 10)
+            $this->font->getStringWidth('aa', 'arial', 10)
         );
 
         // string "i"
         $this->assertEquals(
             3,
-            $this->font->getStringWidth("i", "arial", 10)
+            $this->font->getStringWidth('i', 'arial', 10)
         );
 
         // string "f"
         $this->assertEquals(
             3,
-            $this->font->getStringWidth("f", "arial", 10)
+            $this->font->getStringWidth('f', 'arial', 10)
         );
 
         // string "t"
         $this->assertEquals(
             3,
-            $this->font->getStringWidth("t", "arial", 10)
+            $this->font->getStringWidth('t', 'arial', 10)
         );
 
         // string "if"
         $this->assertEquals(
             5,
-            $this->font->getStringWidth("if", "arial", 10)
+            $this->font->getStringWidth('if', 'arial', 10)
         );
 
         // string "it"
         $this->assertEquals(
             6,
-            $this->font->getStringWidth("it", "arial", 10)
+            $this->font->getStringWidth('it', 'arial', 10)
         );
 
         // string "r"
         $this->assertEquals(
             4,
-            $this->font->getStringWidth("r", "arial", 10)
+            $this->font->getStringWidth('r', 'arial', 10)
         );
 
         // string "1"
         $this->assertEquals(
             5,
-            $this->font->getStringWidth("1", "arial", 10)
+            $this->font->getStringWidth('1', 'arial', 10)
         );
 
         // string "c"
         $this->assertEquals(
             5,
-            $this->font->getStringWidth("c", "arial", 10)
+            $this->font->getStringWidth('c', 'arial', 10)
         );
 
         // string "F"
         $this->assertEquals(
             7,
-            $this->font->getStringWidth("F", "arial", 10)
+            $this->font->getStringWidth('F', 'arial', 10)
         );
 
         // string "A"
         $this->assertEquals(
             7,
-            $this->font->getStringWidth("A", "arial", 10)
+            $this->font->getStringWidth('A', 'arial', 10)
         );
 
         // string "w"
         $this->assertEquals(
             8,
-            $this->font->getStringWidth("w", "arial", 10)
+            $this->font->getStringWidth('w', 'arial', 10)
         );
 
         // string "G"
         $this->assertEquals(
             8,
-            $this->font->getStringWidth("G", "arial", 10)
+            $this->font->getStringWidth('G', 'arial', 10)
         );
 
         // string "m"
         $this->assertEquals(
             9,
-            $this->font->getStringWidth("m", "arial", 10)
+            $this->font->getStringWidth('m', 'arial', 10)
         );
 
         // string "W"
         $this->assertEquals(
             10,
-            $this->font->getStringWidth("W", "arial", 10)
+            $this->font->getStringWidth('W', 'arial', 10)
         );
 
         // string "$"
         $this->assertEquals(
             3,
-            $this->font->getStringWidth("$", "arial", 10)
+            $this->font->getStringWidth('$', 'arial', 10)
         );
     }
 
@@ -165,25 +165,25 @@ class FontTest extends PmaTestCase
         // string "phpMyAdmin", with Arial 10
         $this->assertEquals(
             59,
-            $this->font->getStringWidth("phpMyAdmin", "arial", 10)
+            $this->font->getStringWidth('phpMyAdmin', 'arial', 10)
         );
 
         // string "phpMyAdmin", with No font
         $this->assertEquals(
             59,
-            $this->font->getStringWidth("phpMyAdmin", "", 10)
+            $this->font->getStringWidth('phpMyAdmin', '', 10)
         );
 
         // string "phpMyAdmin", with Times 10
         $this->assertEquals(
             55,
-            $this->font->getStringWidth("phpMyAdmin", "times", 10)
+            $this->font->getStringWidth('phpMyAdmin', 'times', 10)
         );
 
         // string "phpMyAdmin", with Broadway 10
         $this->assertEquals(
             73,
-            $this->font->getStringWidth("phpMyAdmin", "broadway", 10)
+            $this->font->getStringWidth('phpMyAdmin', 'broadway', 10)
         );
     }
 
@@ -197,25 +197,25 @@ class FontTest extends PmaTestCase
         // string "phpMyAdmin", with font size 0
         $this->assertEquals(
             0,
-            $this->font->getStringWidth("phpMyAdmin", "arial", 0)
+            $this->font->getStringWidth('phpMyAdmin', 'arial', 0)
         );
 
         // string "phpMyAdmin", with Arial 10
         $this->assertEquals(
             59,
-            $this->font->getStringWidth("phpMyAdmin", "arial", 10)
+            $this->font->getStringWidth('phpMyAdmin', 'arial', 10)
         );
 
         // string "phpMyAdmin", with Arial 11
         $this->assertEquals(
             65,
-            $this->font->getStringWidth("phpMyAdmin", "arial", 11)
+            $this->font->getStringWidth('phpMyAdmin', 'arial', 11)
         );
 
         // string "phpMyAdmin", with Arial 20
         $this->assertEquals(
             118,
-            $this->font->getStringWidth("phpMyAdmin", "arial", 20)
+            $this->font->getStringWidth('phpMyAdmin', 'arial', 20)
         );
     }
 
@@ -229,7 +229,7 @@ class FontTest extends PmaTestCase
         // string "a", with invalid charlist (= array without proper structure)
         $this->assertEquals(
             6,
-            $this->font->getStringWidth("a", "arial", 10, ["list"])
+            $this->font->getStringWidth('a', 'arial', 10, ['list'])
         );
 
         // string "a", with invalid charlist (= array without proper structure :
@@ -237,10 +237,10 @@ class FontTest extends PmaTestCase
         $this->assertEquals(
             6,
             $this->font->getStringWidth(
-                "a",
-                "arial",
+                'a',
+                'arial',
                 10,
-                [["chars" => "a"]]
+                [['chars' => 'a']]
             )
         );
 
@@ -249,10 +249,10 @@ class FontTest extends PmaTestCase
         $this->assertEquals(
             6,
             $this->font->getStringWidth(
-                "a",
-                "arial",
+                'a',
+                'arial',
                 10,
-                [["modifier" => 0.61]]
+                [['modifier' => 0.61]]
             )
         );
 
@@ -261,13 +261,13 @@ class FontTest extends PmaTestCase
         $this->assertEquals(
             6,
             $this->font->getStringWidth(
-                "a",
-                "arial",
+                'a',
+                'arial',
                 10,
                 [
                     [
-                        "chars" => "a",
-                        "modifier" => 0.61,
+                        'chars' => 'a',
+                        'modifier' => 0.61,
                     ],
                 ]
             )
@@ -277,13 +277,13 @@ class FontTest extends PmaTestCase
         $this->assertEquals(
             7,
             $this->font->getStringWidth(
-                "a",
-                "arial",
+                'a',
+                'arial',
                 10,
                 [
                     [
-                        "chars" => ["a"],
-                        "modifier" => 0.61,
+                        'chars' => ['a'],
+                        'modifier' => 0.61,
                     ],
                 ]
             )
diff --git a/test/classes/GetCheckboxTest.php b/test/classes/GetCheckboxTest.php
index c8d63c0f48..d20ee3968b 100644
--- a/test/classes/GetCheckboxTest.php
+++ b/test/classes/GetCheckboxTest.php
@@ -42,8 +42,8 @@ class GetCheckboxTest extends TestCase
      */
     public function testGetCheckbox()
     {
-        $name = "test_display_html_checkbox";
-        $label = "text_label_for_checkbox";
+        $name = 'test_display_html_checkbox';
+        $label = 'text_label_for_checkbox';
 
         $this->assertSame(
             $this->template->render('checkbox', [
@@ -66,8 +66,8 @@ class GetCheckboxTest extends TestCase
      */
     public function testGetCheckboxChecked()
     {
-        $name = "test_display_html_checkbox";
-        $label = "text_label_for_checkbox";
+        $name = 'test_display_html_checkbox';
+        $label = 'text_label_for_checkbox';
 
         $this->assertSame(
             $this->template->render('checkbox', [
@@ -90,8 +90,8 @@ class GetCheckboxTest extends TestCase
      */
     public function testGetCheckboxOnclick()
     {
-        $name = "test_display_html_checkbox";
-        $label = "text_label_for_checkbox";
+        $name = 'test_display_html_checkbox';
+        $label = 'text_label_for_checkbox';
 
         $this->assertSame(
             $this->template->render('checkbox', [
@@ -114,8 +114,8 @@ class GetCheckboxTest extends TestCase
      */
     public function testGetCheckboxCheckedOnclick()
     {
-        $name = "test_display_html_checkbox";
-        $label = "text_label_for_checkbox";
+        $name = 'test_display_html_checkbox';
+        $label = 'text_label_for_checkbox';
 
         $this->assertSame(
             $this->template->render('checkbox', [
diff --git a/test/classes/Gis/GisGeometryTest.php b/test/classes/Gis/GisGeometryTest.php
index 1beb57c13e..0b45288d86 100644
--- a/test/classes/Gis/GisGeometryTest.php
+++ b/test/classes/Gis/GisGeometryTest.php
@@ -166,7 +166,7 @@ class GisGeometryTest extends TestCase
                 ],
             ],
             [
-                "foo",
+                'foo',
                 [
                     'srid' => '0',
                     'wkt'  => '',
diff --git a/test/classes/Html/GeneratorTest.php b/test/classes/Html/GeneratorTest.php
index 6c472a194a..3176cf3532 100644
--- a/test/classes/Html/GeneratorTest.php
+++ b/test/classes/Html/GeneratorTest.php
@@ -132,7 +132,7 @@ class GeneratorTest extends PmaTestCase
 
         $this->assertXmlStringEqualsXmlString(
             '<root>' . Generator::getDivForSliderEffect($id, $message) . '</div></root>',
-            "<root><div id=\"$id\" class=\"pma_auto_slider\"\ntitle=\""
+            '<root><div id="' . $id . "\" class=\"pma_auto_slider\"\ntitle=\""
             . htmlspecialchars($message) . "\" >\n</div></root>"
         );
     }
@@ -156,7 +156,7 @@ class GeneratorTest extends PmaTestCase
 
         $this->assertXmlStringEqualsXmlString(
             '<root>' . Generator::getDivForSliderEffect($id, $message) . '</div></root>',
-            "<root><div id=\"$id\" style=\"display: none; overflow:auto;\" class=\"pma_auto_slider\"\ntitle=\""
+            '<root><div id="' . $id . "\" style=\"display: none; overflow:auto;\" class=\"pma_auto_slider\"\ntitle=\""
             . htmlspecialchars($message) . "\" >\n</div></root>"
         );
     }
@@ -180,7 +180,7 @@ class GeneratorTest extends PmaTestCase
 
         $this->assertXmlStringEqualsXmlString(
             '<root>' . Generator::getDivForSliderEffect($id, $message) . '</div></root>',
-            "<root><div id=\"$id\">\n</div></root>"
+            '<root><div id="' . $id . "\">\n</div></root>"
         );
     }
 
diff --git a/test/classes/IndexTest.php b/test/classes/IndexTest.php
index dd7a6a9cd0..c5f7e77aa7 100644
--- a/test/classes/IndexTest.php
+++ b/test/classes/IndexTest.php
@@ -27,36 +27,36 @@ class IndexTest extends PmaTestCase
      */
     protected function setUp(): void
     {
-        $this->_params['Schema'] = "PMA_Schema";
-        $this->_params['Table'] = "PMA_Table";
-        $this->_params['Key_name'] = "PMA_Key_name";
-        $this->_params['Index_choice'] = "PMA_Index_choice";
-        $this->_params['Comment'] = "PMA_Comment";
-        $this->_params['Index_comment'] = "PMA_Index_comment";
-        $this->_params['Non_unique'] = "PMA_Non_unique";
-        $this->_params['Packed'] = "PMA_Packed";
+        $this->_params['Schema'] = 'PMA_Schema';
+        $this->_params['Table'] = 'PMA_Table';
+        $this->_params['Key_name'] = 'PMA_Key_name';
+        $this->_params['Index_choice'] = 'PMA_Index_choice';
+        $this->_params['Comment'] = 'PMA_Comment';
+        $this->_params['Index_comment'] = 'PMA_Index_comment';
+        $this->_params['Non_unique'] = 'PMA_Non_unique';
+        $this->_params['Packed'] = 'PMA_Packed';
 
         //test add columns
         $column1 = [
-            "Column_name" => "column1",
-            "Seq_in_index" => "index1",
-            "Collation" => "Collation1",
-            "Cardinality" => "Cardinality1",
-            "Null" => "null1",
+            'Column_name' => 'column1',
+            'Seq_in_index' => 'index1',
+            'Collation' => 'Collation1',
+            'Cardinality' => 'Cardinality1',
+            'Null' => 'null1',
         ];
         $column2 = [
-            "Column_name" => "column2",
-            "Seq_in_index" => "index2",
-            "Collation" => "Collation2",
-            "Cardinality" => "Cardinality2",
-            "Null" => "null2",
+            'Column_name' => 'column2',
+            'Seq_in_index' => 'index2',
+            'Collation' => 'Collation2',
+            'Cardinality' => 'Cardinality2',
+            'Null' => 'null2',
         ];
         $column3 = [
-            "Column_name" => "column3",
-            "Seq_in_index" => "index3",
-            "Collation" => "Collation3",
-            "Cardinality" => "Cardinality3",
-            "Null" => "null3",
+            'Column_name' => 'column3',
+            'Seq_in_index' => 'index3',
+            'Collation' => 'Collation3',
+            'Cardinality' => 'Cardinality3',
+            'Null' => 'null3',
         ];
         $this->_params['columns'][] = $column1;
         $this->_params['columns'][] = $column2;
@@ -116,7 +116,7 @@ class IndexTest extends PmaTestCase
         $this->assertCount(5, $index_choices);
         $this->assertEquals(
             'PRIMARY,INDEX,UNIQUE,SPATIAL,FULLTEXT',
-            implode(",", $index_choices)
+            implode(',', $index_choices)
         );
     }
 
@@ -127,7 +127,7 @@ class IndexTest extends PmaTestCase
      */
     public function testIsUniquer()
     {
-        $this->_params['Non_unique'] = "0";
+        $this->_params['Non_unique'] = '0';
         $index = new Index($this->_params);
         $this->assertTrue(
             $index->isUnique()
@@ -147,9 +147,9 @@ class IndexTest extends PmaTestCase
     {
         $index = new Index();
         $index->addColumns($this->_params['columns']);
-        $this->assertTrue($index->hasColumn("column1"));
-        $this->assertTrue($index->hasColumn("column2"));
-        $this->assertTrue($index->hasColumn("column3"));
+        $this->assertTrue($index->hasColumn('column1'));
+        $this->assertTrue($index->hasColumn('column2'));
+        $this->assertTrue($index->hasColumn('column3'));
         $this->assertEquals(
             3,
             $index->getColumnCount()
diff --git a/test/classes/InsertEditTest.php b/test/classes/InsertEditTest.php
index a5942d03d1..d66fa3462e 100644
--- a/test/classes/InsertEditTest.php
+++ b/test/classes/InsertEditTest.php
@@ -855,7 +855,7 @@ class InsertEditTest extends TestCase
             2,
             0,
             1,
-            "<script>",
+            '<script>',
             $foreigners,
             [],
             false,
@@ -899,7 +899,7 @@ class InsertEditTest extends TestCase
             2,
             0,
             1,
-            "<script>",
+            '<script>',
             [],
             [],
             false,
@@ -919,7 +919,7 @@ class InsertEditTest extends TestCase
             2,
             0,
             1,
-            "<script>",
+            '<script>',
             [],
             [],
             true,
@@ -1007,7 +1007,7 @@ class InsertEditTest extends TestCase
             2,
             0,
             1,
-            "abc",
+            'abc',
             [
                 'tbl',
                 'db',
@@ -1062,7 +1062,7 @@ class InsertEditTest extends TestCase
             2,
             0,
             1,
-            "<s>",
+            '<s>',
             $foreignData,
             false,
         ]);
@@ -1107,7 +1107,7 @@ class InsertEditTest extends TestCase
             2,
             0,
             1,
-            "<s>",
+            '<s>',
             $foreignData,
             false,
         ]);
@@ -1154,7 +1154,7 @@ class InsertEditTest extends TestCase
             2,
             0,
             1,
-            "abc/",
+            'abc/',
             'foobar',
             'CHAR',
             false,
@@ -1573,7 +1573,7 @@ class InsertEditTest extends TestCase
         );
 
         // case 2
-        $GLOBALS['cfg']['ProtectBinary'] = "all";
+        $GLOBALS['cfg']['ProtectBinary'] = 'all';
         $column['is_binary'] = true;
 
         $result = $this->callProtectedMethod('getBinaryAndBlobColumn', [
@@ -1602,7 +1602,7 @@ class InsertEditTest extends TestCase
         );
 
         // case 3
-        $GLOBALS['cfg']['ProtectBinary'] = "noblob";
+        $GLOBALS['cfg']['ProtectBinary'] = 'noblob';
         $column['is_blob'] = false;
 
         $result = $this->callProtectedMethod('getBinaryAndBlobColumn', [
@@ -1892,8 +1892,8 @@ class InsertEditTest extends TestCase
             '&lt;',
             12,
             1,
-            "/",
-            "&lt;",
+            '/',
+            '&lt;',
             "foo\nbar",
             $extracted_columnspec,
             false,
@@ -1923,8 +1923,8 @@ class InsertEditTest extends TestCase
             '&lt;',
             12,
             1,
-            "/",
-            "&lt;",
+            '/',
+            '&lt;',
             "foo\nbar",
             $extracted_columnspec,
             false,
@@ -1951,8 +1951,8 @@ class InsertEditTest extends TestCase
             '&lt;',
             12,
             1,
-            "/",
-            "&lt;",
+            '/',
+            '&lt;',
             "foo\nbar",
             $extracted_columnspec,
             false,
@@ -2026,18 +2026,18 @@ class InsertEditTest extends TestCase
      */
     public function testGetContinueInsertionForm()
     {
-        $where_clause_array = ["a<b"];
+        $where_clause_array = ['a<b'];
         $GLOBALS['cfg']['InsertRows'] = 1;
         $GLOBALS['cfg']['ServerDefault'] = 1;
-        $GLOBALS['goto'] = "index.php";
+        $GLOBALS['goto'] = 'index.php';
         $_POST['where_clause'] = true;
-        $_POST['sql_query'] = "SELECT 1";
+        $_POST['sql_query'] = 'SELECT 1';
 
         $result = $this->insertEdit->getContinueInsertionForm(
-            "tbl",
-            "db",
+            'tbl',
+            'db',
             $where_clause_array,
-            "localhost"
+            'localhost'
         );
 
         $this->assertStringContainsString(
@@ -2136,7 +2136,7 @@ class InsertEditTest extends TestCase
     public function testGetAfterInsertDropDown()
     {
         $result = $this->callProtectedMethod('getAfterInsertDropDown', [
-            "`t`.`f` = 2",
+            '`t`.`f` = 2',
             'new_insert',
             true,
         ]);
@@ -2259,7 +2259,7 @@ class InsertEditTest extends TestCase
         // Case 2 (bit)
         unset($_POST['default_action']);
 
-        $current_row['f'] = "123";
+        $current_row['f'] = '123';
         $extracted_columnspec['spec_in_brackets'] = 20;
         $column['True_Type'] = 'bit';
 
@@ -2276,15 +2276,15 @@ class InsertEditTest extends TestCase
         $this->assertEquals(
             [
                 false,
-                "",
-                "00000000000001111011",
+                '',
+                '00000000000001111011',
                 null,
                 '<input type="hidden" name="fields_preva" value="123">',
             ],
             $result
         );
 
-        $current_row['f'] = "abcd";
+        $current_row['f'] = 'abcd';
         $result = $this->callProtectedMethod('getSpecialCharsAndBackupFieldForExistingRow', [
             $current_row,
             $column,
@@ -2298,8 +2298,8 @@ class InsertEditTest extends TestCase
         $this->assertEquals(
             [
                 false,
-                "",
-                "abcd",
+                '',
+                'abcd',
                 null,
                 '<input type="hidden" name="fields_preva" value="abcd">',
             ],
@@ -2314,7 +2314,7 @@ class InsertEditTest extends TestCase
         $GLOBALS['dbi'] = $dbi;
         $this->insertEdit = new InsertEdit($GLOBALS['dbi']);
 
-        $current_row['f'] = "123";
+        $current_row['f'] = '123';
         $extracted_columnspec['spec_in_brackets'] = 20;
         $column['True_Type'] = 'int';
 
@@ -2331,7 +2331,7 @@ class InsertEditTest extends TestCase
         $this->assertEquals(
             [
                 false,
-                "",
+                '',
                 "'',",
                 null,
                 '<input type="hidden" name="fields_preva" value="\'\',">',
@@ -2343,7 +2343,7 @@ class InsertEditTest extends TestCase
         $column['is_binary'] = false;
         $column['is_blob'] = true;
         $GLOBALS['cfg']['ProtectBinary'] = false;
-        $current_row['f'] = "11001";
+        $current_row['f'] = '11001';
         $extracted_columnspec['spec_in_brackets'] = 20;
         $column['True_Type'] = 'char';
         $GLOBALS['cfg']['ShowFunctionFields'] = true;
@@ -2361,9 +2361,9 @@ class InsertEditTest extends TestCase
         $this->assertEquals(
             [
                 false,
-                "3131303031",
-                "3131303031",
-                "3131303031",
+                '3131303031',
+                '3131303031',
+                '3131303031',
                 '<input type="hidden" name="fields_preva" value="3131303031">',
             ],
             $result
@@ -2385,9 +2385,9 @@ class InsertEditTest extends TestCase
         $this->assertEquals(
             [
                 false,
-                "313130303100",
-                "313130303100",
-                "313130303100",
+                '313130303100',
+                '313130303100',
+                '313130303100',
                 '<input type="hidden" name="fields_preva" value="313130303100">',
             ],
             $result
@@ -2889,8 +2889,8 @@ class InsertEditTest extends TestCase
 
         $this->assertEquals(
             [
-                "1: #42 msg1",
-                "2: #43 msg2",
+                '1: #42 msg1',
+                '2: #43 msg2',
             ],
             $result
         );
@@ -2935,7 +2935,7 @@ class InsertEditTest extends TestCase
         $GLOBALS['dbi'] = $dbi;
         $this->insertEdit = new InsertEdit($GLOBALS['dbi']);
 
-        $result = $this->insertEdit->getDisplayValueForForeignTableColumn("=1", $map, 'f');
+        $result = $this->insertEdit->getDisplayValueForForeignTableColumn('=1', $map, 'f');
 
         $this->assertEquals(2, $result);
     }
@@ -2954,7 +2954,7 @@ class InsertEditTest extends TestCase
         $map['f']['foreign_table'] = 'TABLES';
         $map['f']['foreign_field'] = 'f';
 
-        $result = $this->insertEdit->getLinkForRelationalDisplayField($map, 'f', "=1", "a>", "b<");
+        $result = $this->insertEdit->getLinkForRelationalDisplayField($map, 'f', '=1', 'a>', 'b<');
 
         $this->assertEquals(
             '<a href="index.php?route=/sql&amp;db=information_schema&amp;table=TABLES&amp;pos=0&amp;'
@@ -2964,7 +2964,7 @@ class InsertEditTest extends TestCase
         );
 
         $_SESSION['tmpval']['relational_display'] = 'D';
-        $result = $this->insertEdit->getLinkForRelationalDisplayField($map, 'f', "=1", "a>", "b<");
+        $result = $this->insertEdit->getLinkForRelationalDisplayField($map, 'f', '=1', 'a>', 'b<');
 
         $this->assertEquals(
             '<a href="index.php?route=/sql&amp;db=information_schema&amp;table=TABLES&amp;pos=0&amp;'
@@ -3007,7 +3007,7 @@ class InsertEditTest extends TestCase
         $this->assertEquals(
             [
                 'a' => 'b',
-                'transformations' => ["cnameoption ,, quoted"],
+                'transformations' => ['cnameoption ,, quoted'],
             ],
             $result
         );
@@ -3177,7 +3177,7 @@ class InsertEditTest extends TestCase
 
         // case 3
         $multi_edit_funcs = ['AES_ENCRYPT'];
-        $multi_edit_salt = [""];
+        $multi_edit_salt = [''];
         $result = $this->insertEdit->getCurrentValueAsAnArrayForMultipleEdit(
             $multi_edit_funcs,
             $multi_edit_salt,
@@ -3216,7 +3216,7 @@ class InsertEditTest extends TestCase
             ['func'],
             '0'
         );
-        $this->assertEquals("func()", $result);
+        $this->assertEquals('func()', $result);
     }
 
     /**
@@ -3358,7 +3358,7 @@ class InsertEditTest extends TestCase
         );
 
         $this->assertEquals(
-            "0x313031",
+            '0x313031',
             $result
         );
 
@@ -3381,7 +3381,7 @@ class InsertEditTest extends TestCase
         );
 
         $this->assertEquals(
-            "",
+            '',
             $result
         );
 
@@ -3451,7 +3451,7 @@ class InsertEditTest extends TestCase
         );
 
         $this->assertEquals(
-            "NULL",
+            'NULL',
             $result
         );
 
@@ -3661,7 +3661,7 @@ class InsertEditTest extends TestCase
                 [null],
                 [null],
                 false,
-                "edit_next",
+                'edit_next',
             ],
             $result
         );
@@ -3687,7 +3687,7 @@ class InsertEditTest extends TestCase
                     false,
                 ],
                 false,
-                "edit_next",
+                'edit_next',
             ],
             $result
         );
diff --git a/test/classes/IpAllowDenyTest.php b/test/classes/IpAllowDenyTest.php
index 2e8acffc8e..782385d9c4 100644
--- a/test/classes/IpAllowDenyTest.php
+++ b/test/classes/IpAllowDenyTest.php
@@ -33,20 +33,20 @@ class IpAllowDenyTest extends TestCase
      */
     protected function setUp(): void
     {
-        $GLOBALS['cfg']['Server']['user'] = "pma_username";
+        $GLOBALS['cfg']['Server']['user'] = 'pma_username';
         $GLOBALS['cfg']['Server']['AllowDeny']['rules'][]
-            = "allow % 255.255.255.0/4";
+            = 'allow % 255.255.255.0/4';
         $GLOBALS['cfg']['Server']['AllowDeny']['rules'][]
-            = "allow % from 255.255.2.0/4";
+            = 'allow % from 255.255.2.0/4';
         $GLOBALS['cfg']['Server']['AllowDeny']['rules'][]
-            = "allow % from 2001:4998:c:a0d:0000:0000:4998:1020";
+            = 'allow % from 2001:4998:c:a0d:0000:0000:4998:1020';
         $GLOBALS['cfg']['Server']['AllowDeny']['rules'][]
-            = "allow % from 2001:4998:c:a0d:0000:0000:4998:[1001-2010]";
+            = 'allow % from 2001:4998:c:a0d:0000:0000:4998:[1001-2010]';
         $GLOBALS['cfg']['Server']['AllowDeny']['rules'][]
-            = "allow % from 2001:4998:c:a0d:0000:0000:4998:3020/24";
-        $GLOBALS['cfg']['Server']['AllowDeny']['rules'][] = "deny % 255.255.0.0/8";
+            = 'allow % from 2001:4998:c:a0d:0000:0000:4998:3020/24';
+        $GLOBALS['cfg']['Server']['AllowDeny']['rules'][] = 'deny % 255.255.0.0/8';
         $GLOBALS['cfg']['Server']['AllowDeny']['rules'][]
-            = "deny % from 255.255.0.0/8";
+            = 'deny % from 255.255.0.0/8';
 
         $this->ipAllowDeny = new IpAllowDeny();
     }
@@ -147,27 +147,27 @@ class IpAllowDenyTest extends TestCase
     public function testIpMaskTest()
     {
         //IPV4 testing
-        $testRange = "255.255.0.0/8";
-        $ipToTest = "10.0.0.0";
+        $testRange = '255.255.0.0/8';
+        $ipToTest = '10.0.0.0';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
         );
 
-        $testRange = "255.255.0.0/4";
-        $ipToTest = "255.3.0.0";
+        $testRange = '255.255.0.0/4';
+        $ipToTest = '255.3.0.0';
         $this->assertEquals(
             true,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
         );
 
-        $testRange = "255.255.0.[0-10]";
-        $ipToTest = "255.3.0.3";
+        $testRange = '255.255.0.[0-10]';
+        $ipToTest = '255.3.0.3';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
         );
-        $ipToTest = "255.3.0.12";
+        $ipToTest = '255.3.0.12';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
@@ -175,42 +175,42 @@ class IpAllowDenyTest extends TestCase
 
         //IPV6 testing
         //not range
-        $ipToTest = "2001:4998:c:a0d:0000:0000:4998:1020";
-        $testRange = "2001:4998:c:a0d:0000:0000:4998:1020";
+        $ipToTest = '2001:4998:c:a0d:0000:0000:4998:1020';
+        $testRange = '2001:4998:c:a0d:0000:0000:4998:1020';
         $this->assertEquals(
             true,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
         );
-        $ipToTest = "2001:4998:c:a0d:0000:0000:4998:1020";
-        $testRange = "2001:4998:c:a0d:0000:0000:4998:2020";
+        $ipToTest = '2001:4998:c:a0d:0000:0000:4998:1020';
+        $testRange = '2001:4998:c:a0d:0000:0000:4998:2020';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
         );
 
         //range
-        $ipToTest = "2001:4998:c:a0d:0000:0000:4998:1020";
-        $testRange = "2001:4998:c:a0d:0000:0000:4998:[1001-2010]";
+        $ipToTest = '2001:4998:c:a0d:0000:0000:4998:1020';
+        $testRange = '2001:4998:c:a0d:0000:0000:4998:[1001-2010]';
         $this->assertEquals(
             true,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
         );
-        $ipToTest = "2001:4998:c:a0d:0000:0000:4998:3020";
-        $testRange = "2001:4998:c:a0d:0000:0000:4998:[1001-2010]";
+        $ipToTest = '2001:4998:c:a0d:0000:0000:4998:3020';
+        $testRange = '2001:4998:c:a0d:0000:0000:4998:[1001-2010]';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
         );
 
         //CDIR
-        $ipToTest = "2001:4998:c:a0d:0000:0000:4998:1020";
-        $testRange = "2001:4998:c:a0d:0000:0000:4998:[1001-2010]";
+        $ipToTest = '2001:4998:c:a0d:0000:0000:4998:1020';
+        $testRange = '2001:4998:c:a0d:0000:0000:4998:[1001-2010]';
         $this->assertEquals(
             true,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
         );
-        $ipToTest = "2001:4998:c:a0d:0000:0000:4998:1000";
-        $testRange = "2001:4998:c:a0d:0000:0000:4998:3020/24";
+        $ipToTest = '2001:4998:c:a0d:0000:0000:4998:1000';
+        $testRange = '2001:4998:c:a0d:0000:0000:4998:3020/24';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->ipMaskTest($testRange, $ipToTest)
@@ -224,51 +224,51 @@ class IpAllowDenyTest extends TestCase
      */
     public function testAllowDeny()
     {
-        $_SERVER['REMOTE_ADDR'] = "";
+        $_SERVER['REMOTE_ADDR'] = '';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->allow()
         );
 
-        $_SERVER['REMOTE_ADDR'] = "255.0.1.0";
+        $_SERVER['REMOTE_ADDR'] = '255.0.1.0';
         $this->assertEquals(
             true,
             $this->ipAllowDeny->allow()
         );
-        $_SERVER['REMOTE_ADDR'] = "10.0.0.0";
+        $_SERVER['REMOTE_ADDR'] = '10.0.0.0';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->allow()
         );
 
-        $_SERVER['REMOTE_ADDR'] = "255.255.0.1";
+        $_SERVER['REMOTE_ADDR'] = '255.255.0.1';
         $this->assertEquals(
             true,
             $this->ipAllowDeny->deny()
         );
-        $_SERVER['REMOTE_ADDR'] = "255.124.0.5";
+        $_SERVER['REMOTE_ADDR'] = '255.124.0.5';
         $this->assertEquals(
             true,
             $this->ipAllowDeny->deny()
         );
-        $_SERVER['REMOTE_ADDR'] = "122.124.0.5";
+        $_SERVER['REMOTE_ADDR'] = '122.124.0.5';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->deny()
         );
 
         //IPV6
-        $_SERVER['REMOTE_ADDR'] = "2001:4998:c:a0d:0000:0000:4998:1020";
+        $_SERVER['REMOTE_ADDR'] = '2001:4998:c:a0d:0000:0000:4998:1020';
         $this->assertEquals(
             true,
             $this->ipAllowDeny->allow()
         );
-        $_SERVER['REMOTE_ADDR'] = "2001:4998:c:a0d:0000:0000:4998:1000";
+        $_SERVER['REMOTE_ADDR'] = '2001:4998:c:a0d:0000:0000:4998:1000';
         $this->assertEquals(
             false,
             $this->ipAllowDeny->allow()
         );
-        $_SERVER['REMOTE_ADDR'] = "2001:4998:c:a0d:0000:0000:4998:1020";
+        $_SERVER['REMOTE_ADDR'] = '2001:4998:c:a0d:0000:0000:4998:1020';
         $this->assertEquals(
             true,
             $this->ipAllowDeny->allow()
diff --git a/test/classes/LinterTest.php b/test/classes/LinterTest.php
index 252464eac5..342bf6c80f 100644
--- a/test/classes/LinterTest.php
+++ b/test/classes/LinterTest.php
@@ -144,7 +144,7 @@ class LinterTest extends PmaTestCase
                         'severity' => 'warning',
                     ],
                 ],
-                str_repeat(";", 10001),
+                str_repeat(';', 10001),
             ],
         ];
     }
diff --git a/test/classes/MessageTest.php b/test/classes/MessageTest.php
index 42501b8f0b..0ae8dc67b9 100644
--- a/test/classes/MessageTest.php
+++ b/test/classes/MessageTest.php
@@ -310,15 +310,15 @@ class MessageTest extends PmaTestCase
     public function testAddMessages()
     {
         $messages = [];
-        $messages[] = new Message("Test1");
-        $messages[] = new Message("PMA_Test2", Message::ERROR);
-        $messages[] = new Message("Test3");
+        $messages[] = new Message('Test1');
+        $messages[] = new Message('PMA_Test2', Message::ERROR);
+        $messages[] = new Message('Test3');
         $this->object->addMessages($messages, '');
 
         $this->assertEquals(
             [
                 Message::notice('Test1'),
-                Message::error("PMA_Test2"),
+                Message::error('PMA_Test2'),
                 Message::notice('Test3'),
             ],
             $this->object->getAddedMessages()
diff --git a/test/classes/MultSubmitsTest.php b/test/classes/MultSubmitsTest.php
index 07e246a7a4..97ceaa48f1 100644
--- a/test/classes/MultSubmitsTest.php
+++ b/test/classes/MultSubmitsTest.php
@@ -32,7 +32,7 @@ class MultSubmitsTest extends TestCase
     {
         //$GLOBALS
         $GLOBALS['cfg']['MaxRows'] = 10;
-        $GLOBALS['cfg']['ServerDefault'] = "server";
+        $GLOBALS['cfg']['ServerDefault'] = 'server';
         $GLOBALS['cfg']['RememberSorting'] = true;
         $GLOBALS['cfg']['SQP'] = [];
         $GLOBALS['cfg']['MaxCharactersInDisplayedSQL'] = 1000;
@@ -41,14 +41,14 @@ class MultSubmitsTest extends TestCase
         $GLOBALS['cfg']['LimitChars'] = 100;
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
         $GLOBALS['server'] = 0;
-        $GLOBALS['cfg']['ActionLinksMode'] = "both";
+        $GLOBALS['cfg']['ActionLinksMode'] = 'both';
 
         //_SESSION
         $_SESSION['relation'][$GLOBALS['server']] = [
             'PMA_VERSION' => PMA_VERSION,
-            'table_coords' => "table_name",
+            'table_coords' => 'table_name',
             'displaywork' => 'displaywork',
-            'db' => "information_schema",
+            'db' => 'information_schema',
             'table_info' => 'table_info',
             'relwork' => 'relwork',
             'commwork' => 'commwork',
@@ -194,14 +194,14 @@ class MultSubmitsTest extends TestCase
         $what = 'row_delete';
         $reload = true;
         $action = 'db_delete_row';
-        $db = "PMA_db";
-        $table = "PMA_table";
+        $db = 'PMA_db';
+        $table = 'PMA_table';
         $selected = [
-            "index1" => "table1",
+            'index1' => 'table1',
         ];
         $views = null;
-        $originalSqlQuery = "original_sql_query";
-        $originalUrlQuery = "original_url_query";
+        $originalSqlQuery = 'original_sql_query';
+        $originalUrlQuery = 'original_url_query';
 
         $urlParams = $this->multSubmits->getUrlParams(
             $what,
@@ -244,16 +244,16 @@ class MultSubmitsTest extends TestCase
     public function testBuildOrExecuteQuery()
     {
         $queryType = 'row_delete';
-        $db = "PMA_db";
-        $table = "PMA_table";
+        $db = 'PMA_db';
+        $table = 'PMA_table';
         $selected = [
-            "table1",
-            "table2",
+            'table1',
+            'table2',
         ];
         $views = null;
         $primary = null;
-        $fromPrefix = "from_prefix";
-        $toPrefix = "to_prefix";
+        $fromPrefix = 'from_prefix';
+        $toPrefix = 'to_prefix';
 
         $_REQUEST['pos'] = 1000;
         $_SESSION['tmpval']['pos'] = 1000;
@@ -325,15 +325,15 @@ class MultSubmitsTest extends TestCase
      */
     public function testGetQueryFromSelected()
     {
-        $what = "drop_tbl";
-        $table = "PMA_table";
+        $what = 'drop_tbl';
+        $table = 'PMA_table';
         $selected = [
-            "table1",
-            "table2",
+            'table1',
+            'table2',
         ];
         $views = [
-            "table1",
-            "table2",
+            'table1',
+            'table2',
         ];
 
         list($fullQuery, $reload, $fullQueryViews)
@@ -346,7 +346,7 @@ class MultSubmitsTest extends TestCase
 
         //validate 1: $fullQuery
         $this->assertStringContainsString(
-            "DROP VIEW `table1`, `table2`",
+            'DROP VIEW `table1`, `table2`',
             $fullQuery
         );
 
@@ -362,7 +362,7 @@ class MultSubmitsTest extends TestCase
             $fullQueryViews
         );
 
-        $what = "drop_db";
+        $what = 'drop_db';
 
         list($fullQuery, $reload, $fullQueryViews)
             = $this->multSubmits->getQueryFromSelected(
@@ -374,7 +374,7 @@ class MultSubmitsTest extends TestCase
 
         //validate 1: $fullQuery
         $this->assertStringContainsString(
-            "DROP DATABASE `table1`;<br>DROP DATABASE `table2`;",
+            'DROP DATABASE `table1`;<br>DROP DATABASE `table2`;',
             $fullQuery
         );
 
diff --git a/test/classes/Navigation/NavigationTest.php b/test/classes/Navigation/NavigationTest.php
index abcef04a7f..064117a1fa 100644
--- a/test/classes/Navigation/NavigationTest.php
+++ b/test/classes/Navigation/NavigationTest.php
@@ -70,8 +70,8 @@ class NavigationTest extends PmaTestCase
      */
     public function testHideNavigationItem()
     {
-        $expectedQuery = "INSERT INTO `pmadb`.`navigationhiding`"
-            . "(`username`, `item_name`, `item_type`, `db_name`, `table_name`)"
+        $expectedQuery = 'INSERT INTO `pmadb`.`navigationhiding`'
+            . '(`username`, `item_name`, `item_type`, `db_name`, `table_name`)'
             . " VALUES ('user','itemName','itemType','db','')";
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
             ->disableOriginalConstructor()
@@ -95,7 +95,7 @@ class NavigationTest extends PmaTestCase
      */
     public function testUnhideNavigationItem()
     {
-        $expectedQuery = "DELETE FROM `pmadb`.`navigationhiding`"
+        $expectedQuery = 'DELETE FROM `pmadb`.`navigationhiding`'
             . " WHERE `username`='user' AND `item_name`='itemName'"
             . " AND `item_type`='itemType' AND `db_name`='db'";
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
diff --git a/test/classes/Navigation/Nodes/NodeTest.php b/test/classes/Navigation/Nodes/NodeTest.php
index fdd4854365..3893b43854 100644
--- a/test/classes/Navigation/Nodes/NodeTest.php
+++ b/test/classes/Navigation/Nodes/NodeTest.php
@@ -61,11 +61,11 @@ class NodeTest extends PmaTestCase
     {
         $parent = NodeFactory::getInstance('Node', 'parent');
         $this->assertEquals(
-            $parent->getChild("foo"),
+            $parent->getChild('foo'),
             false
         );
         $this->assertEquals(
-            $parent->getChild("foo", true),
+            $parent->getChild('foo', true),
             false
         );
     }
@@ -299,7 +299,7 @@ class NodeTest extends PmaTestCase
         // Vanilla case
         $node = NodeFactory::getInstance();
         $this->assertEquals(
-            "WHERE TRUE ",
+            'WHERE TRUE ',
             $method->invoke($node, 'SCHEMA_NAME')
         );
 
@@ -358,23 +358,23 @@ class NodeTest extends PmaTestCase
         $GLOBALS['cfg']['FirstLevelNavigationItems'] = $limit;
         $GLOBALS['cfg']['NavigationTreeDbSeparator'] = '_';
 
-        $expectedSql  = "SELECT `SCHEMA_NAME` ";
-        $expectedSql .= "FROM `INFORMATION_SCHEMA`.`SCHEMATA`, ";
-        $expectedSql .= "(";
-        $expectedSql .= "SELECT DB_first_level ";
-        $expectedSql .= "FROM ( ";
-        $expectedSql .= "SELECT DISTINCT SUBSTRING_INDEX(SCHEMA_NAME, ";
+        $expectedSql  = 'SELECT `SCHEMA_NAME` ';
+        $expectedSql .= 'FROM `INFORMATION_SCHEMA`.`SCHEMATA`, ';
+        $expectedSql .= '(';
+        $expectedSql .= 'SELECT DB_first_level ';
+        $expectedSql .= 'FROM ( ';
+        $expectedSql .= 'SELECT DISTINCT SUBSTRING_INDEX(SCHEMA_NAME, ';
         $expectedSql .= "'_', 1) ";
-        $expectedSql .= "DB_first_level ";
-        $expectedSql .= "FROM INFORMATION_SCHEMA.SCHEMATA ";
-        $expectedSql .= "WHERE TRUE ";
-        $expectedSql .= ") t ";
-        $expectedSql .= "ORDER BY DB_first_level ASC ";
-        $expectedSql .= "LIMIT $pos, $limit";
-        $expectedSql .= ") t2 ";
+        $expectedSql .= 'DB_first_level ';
+        $expectedSql .= 'FROM INFORMATION_SCHEMA.SCHEMATA ';
+        $expectedSql .= 'WHERE TRUE ';
+        $expectedSql .= ') t ';
+        $expectedSql .= 'ORDER BY DB_first_level ASC ';
+        $expectedSql .= 'LIMIT ' . $pos . ', ' . $limit;
+        $expectedSql .= ') t2 ';
         $expectedSql .= "WHERE TRUE AND 1 = LOCATE(CONCAT(DB_first_level, '_'), ";
         $expectedSql .= "CONCAT(SCHEMA_NAME, '_')) ";
-        $expectedSql .= "ORDER BY SCHEMA_NAME ASC";
+        $expectedSql .= 'ORDER BY SCHEMA_NAME ASC';
 
         // It would have been better to mock _getWhereClause method
         // but strangely, mocking private methods is not supported in PHPUnit
@@ -407,11 +407,11 @@ class NodeTest extends PmaTestCase
         $GLOBALS['cfg']['NavigationTreeEnableGrouping'] = false;
         $GLOBALS['cfg']['FirstLevelNavigationItems'] = $limit;
 
-        $expectedSql  = "SELECT `SCHEMA_NAME` ";
-        $expectedSql .= "FROM `INFORMATION_SCHEMA`.`SCHEMATA` ";
-        $expectedSql .= "WHERE TRUE ";
-        $expectedSql .= "ORDER BY `SCHEMA_NAME` ";
-        $expectedSql .= "LIMIT $pos, $limit";
+        $expectedSql  = 'SELECT `SCHEMA_NAME` ';
+        $expectedSql .= 'FROM `INFORMATION_SCHEMA`.`SCHEMATA` ';
+        $expectedSql .= 'WHERE TRUE ';
+        $expectedSql .= 'ORDER BY `SCHEMA_NAME` ';
+        $expectedSql .= 'LIMIT ' . $pos . ', ' . $limit;
 
         // It would have been better to mock _getWhereClause method
         // but strangely, mocking private methods is not supported in PHPUnit
@@ -495,13 +495,13 @@ class NodeTest extends PmaTestCase
         $GLOBALS['cfg']['NavigationTreeEnableGrouping'] = true;
         $GLOBALS['cfg']['NavigationTreeDbSeparator'] = '_';
 
-        $query = "SELECT COUNT(*) ";
-        $query .= "FROM ( ";
+        $query = 'SELECT COUNT(*) ';
+        $query .= 'FROM ( ';
         $query .= "SELECT DISTINCT SUBSTRING_INDEX(SCHEMA_NAME, '_', 1) ";
-        $query .= "DB_first_level ";
-        $query .= "FROM INFORMATION_SCHEMA.SCHEMATA ";
-        $query .= "WHERE TRUE ";
-        $query .= ") t ";
+        $query .= 'DB_first_level ';
+        $query .= 'FROM INFORMATION_SCHEMA.SCHEMATA ';
+        $query .= 'WHERE TRUE ';
+        $query .= ') t ';
 
         // It would have been better to mock _getWhereClause method
         // but strangely, mocking private methods is not supported in PHPUnit
@@ -529,9 +529,9 @@ class NodeTest extends PmaTestCase
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
         $GLOBALS['cfg']['NavigationTreeEnableGrouping'] = false;
 
-        $query = "SELECT COUNT(*) ";
-        $query .= "FROM INFORMATION_SCHEMA.SCHEMATA ";
-        $query .= "WHERE TRUE ";
+        $query = 'SELECT COUNT(*) ';
+        $query .= 'FROM INFORMATION_SCHEMA.SCHEMATA ';
+        $query .= 'WHERE TRUE ';
 
         $node = NodeFactory::getInstance();
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
@@ -564,7 +564,7 @@ class NodeTest extends PmaTestCase
             ->getMock();
         $dbi->expects($this->once())
             ->method('tryQuery')
-            ->with("SHOW DATABASES WHERE TRUE ");
+            ->with('SHOW DATABASES WHERE TRUE ');
         $dbi->expects($this->any())->method('escapeString')
             ->will($this->returnArgument(0));
 
diff --git a/test/classes/NormalizationTest.php b/test/classes/NormalizationTest.php
index fde4ddeb1a..b95fd61115 100644
--- a/test/classes/NormalizationTest.php
+++ b/test/classes/NormalizationTest.php
@@ -37,7 +37,7 @@ class NormalizationTest extends TestCase
     protected function setUp(): void
     {
         $GLOBALS['cfg']['LimitChars'] = 50;
-        $GLOBALS['cfg']['ServerDefault'] = "PMA_server";
+        $GLOBALS['cfg']['ServerDefault'] = 'PMA_server';
         $GLOBALS['cfg']['ShowHint'] = true;
         $GLOBALS['cfg']['CharEditing'] = '';
         $GLOBALS['cfg']['ActionLinksMode'] = 'icons';
@@ -64,15 +64,15 @@ class NormalizationTest extends TestCase
             ->will(
                 $this->returnValue(
                     [
-                        "id" => ["Type" => "integer"],
-                        "col1" => ["Type" => 'varchar(100)'],
-                        "col2" => ["Type" => 'DATETIME'],
+                        'id' => ['Type' => 'integer'],
+                        'col1' => ['Type' => 'varchar(100)'],
+                        'col2' => ['Type' => 'DATETIME'],
                     ]
                 )
             );
         $dbi->expects($this->any())
             ->method('getColumnNames')
-            ->will($this->returnValue(["id", "col1", "col2"]));
+            ->will($this->returnValue(['id', 'col1', 'col2']));
         $map = [
             [
                 'PMA_db',
@@ -127,8 +127,8 @@ class NormalizationTest extends TestCase
      */
     public function testGetHtmlForColumnsList()
     {
-        $db = "PMA_db";
-        $table = "PMA_table";
+        $db = 'PMA_db';
+        $table = 'PMA_table';
         $this->assertStringContainsString(
             '<option value="id">id [ integer ]</option>',
             $this->normalization->getHtmlForColumnsList($table, $db)
@@ -149,8 +149,8 @@ class NormalizationTest extends TestCase
         $GLOBALS['cfg']['BrowseMIME'] = true;
         $GLOBALS['cfg']['MaxRows'] = 25;
         $GLOBALS['col_priv'] = false;
-        $db = "PMA_db";
-        $table = "PMA_table";
+        $db = 'PMA_db';
+        $table = 'PMA_table';
         $numFields = 1;
         $result = $this->normalization->getHtmlForCreateNewColumn($numFields, $db, $table);
         $this->assertStringContainsString(
@@ -166,20 +166,20 @@ class NormalizationTest extends TestCase
      */
     public function testGetHtmlFor1NFStep1()
     {
-        $db = "PMA_db";
-        $table = "PMA_table";
+        $db = 'PMA_db';
+        $table = 'PMA_table';
         $normalizedTo = '1nf';
         $result = $this->normalization->getHtmlFor1NFStep1($db, $table, $normalizedTo);
         $this->assertStringContainsString(
             "<h3 class='text-center'>"
-            . __('First step of normalization (1NF)') . "</h3>",
+            . __('First step of normalization (1NF)') . '</h3>',
             $result
         );
         $this->assertStringContainsString(
             "<div id='mainContent'",
             $result
         );
-        $this->assertStringContainsString("<legend>" . __('Step 1.'), $result);
+        $this->assertStringContainsString('<legend>' . __('Step 1.'), $result);
 
         $this->assertStringContainsString(
             '<h4',
@@ -213,8 +213,8 @@ class NormalizationTest extends TestCase
      */
     public function testGetHtmlContentsFor1NFStep2()
     {
-        $db = "PMA_db";
-        $table = "PMA_table1";
+        $db = 'PMA_db';
+        $table = 'PMA_table1';
         $result = $this->normalization->getHtmlContentsFor1NFStep2($db, $table);
         $this->assertIsArray($result);
         $this->assertArrayHasKey('legendText', $result);
@@ -243,8 +243,8 @@ class NormalizationTest extends TestCase
      */
     public function testGetHtmlContentsFor1NFStep4()
     {
-        $db = "PMA_db";
-        $table = "PMA_table";
+        $db = 'PMA_db';
+        $table = 'PMA_table';
         $result = $this->normalization->getHtmlContentsFor1NFStep4($db, $table);
         $this->assertIsArray($result);
         $this->assertArrayHasKey('legendText', $result);
@@ -253,7 +253,7 @@ class NormalizationTest extends TestCase
         $this->assertArrayHasKey('extra', $result);
         $this->assertStringContainsString(__('Step 1.') . 4, $result['legendText']);
         $this->assertStringContainsString(
-            $this->normalization->getHtmlForColumnsList($db, $table, 'all', "checkbox"),
+            $this->normalization->getHtmlForColumnsList($db, $table, 'all', 'checkbox'),
             $result['extra']
         );
         $this->assertStringContainsString(
@@ -269,8 +269,8 @@ class NormalizationTest extends TestCase
      */
     public function testGetHtmlContentsFor1NFStep3()
     {
-        $db = "PMA_db";
-        $table = "PMA_table";
+        $db = 'PMA_db';
+        $table = 'PMA_table';
         $result = $this->normalization->getHtmlContentsFor1NFStep3($db, $table);
         $this->assertIsArray($result);
         $this->assertArrayHasKey('legendText', $result);
@@ -280,7 +280,7 @@ class NormalizationTest extends TestCase
         $this->assertArrayHasKey('primary_key', $result);
         $this->assertStringContainsString(__('Step 1.') . 3, $result['legendText']);
         $this->assertStringContainsString(
-            $this->normalization->getHtmlForColumnsList($db, $table, 'all', "checkbox"),
+            $this->normalization->getHtmlForColumnsList($db, $table, 'all', 'checkbox'),
             $result['extra']
         );
         $this->assertStringContainsString(
@@ -297,8 +297,8 @@ class NormalizationTest extends TestCase
      */
     public function testGetHtmlFor2NFstep1()
     {
-        $db = "PMA_db";
-        $table = "PMA_table";
+        $db = 'PMA_db';
+        $table = 'PMA_table';
         $result = $this->normalization->getHtmlFor2NFstep1($db, $table);
         $this->assertIsArray($result);
         $this->assertArrayHasKey('legendText', $result);
@@ -308,7 +308,7 @@ class NormalizationTest extends TestCase
         $this->assertArrayHasKey('primary_key', $result);
         $this->assertStringContainsString(__('Step 2.') . 1, $result['legendText']);
         $this->assertEquals('id', $result['primary_key']);
-        $result1 = $this->normalization->getHtmlFor2NFstep1($db, "PMA_table2");
+        $result1 = $this->normalization->getHtmlFor2NFstep1($db, 'PMA_table2');
         $this->assertEquals('id, col1', $result1['primary_key']);
         $this->assertStringContainsString(
             '<a href="#" id="showPossiblePd"',
@@ -327,7 +327,7 @@ class NormalizationTest extends TestCase
      */
     public function testGetHtmlForNewTables2NF()
     {
-        $table = "PMA_table";
+        $table = 'PMA_table';
         $partialDependencies = ['col1' => ['col2']];
         $result = $this->normalization->getHtmlForNewTables2NF($partialDependencies, $table);
         $this->assertStringContainsString(
@@ -343,7 +343,7 @@ class NormalizationTest extends TestCase
      */
     public function testCreateNewTablesFor2NF()
     {
-        $table = "PMA_table";
+        $table = 'PMA_table';
         $db = 'PMA_db';
         $tablesName = new stdClass();
         $tablesName->id = 'PMA_table';
@@ -381,7 +381,7 @@ class NormalizationTest extends TestCase
      */
     public function testGetHtmlForNewTables3NF()
     {
-        $tables = ["PMA_table" => ['col1']];
+        $tables = ['PMA_table' => ['col1']];
         $db = 'PMA_db';
         $dependencies = new stdClass();
         $dependencies->col1 = ['col2'];
@@ -395,7 +395,7 @@ class NormalizationTest extends TestCase
             $result
         );
         $tables = [
-            "PMA_table" => [
+            'PMA_table' => [
                 'col1',
                 'PMA_table',
             ],
@@ -476,7 +476,7 @@ class NormalizationTest extends TestCase
         $primaryColumns = 'id,col1';
         $newTable = 'PMA_newTable';
         $newColumn = 'PMA_newCol';
-        $table = "PMA_table";
+        $table = 'PMA_table';
         $db = 'PMA_db';
         $result = $this->normalization->moveRepeatingGroup(
             $repeatingColumns,
@@ -502,8 +502,8 @@ class NormalizationTest extends TestCase
      */
     public function testGetHtmlFor3NFstep1()
     {
-        $db = "PMA_db";
-        $tables = ["PMA_table"];
+        $db = 'PMA_db';
+        $tables = ['PMA_table'];
         $result = $this->normalization->getHtmlFor3NFstep1($db, $tables);
         $this->assertIsArray($result);
         $this->assertArrayHasKey('legendText', $result);
@@ -519,7 +519,7 @@ class NormalizationTest extends TestCase
             '<input type="checkbox" name="pd" value="col1"',
             $result['extra']
         );
-        $result1 = $this->normalization->getHtmlFor3NFstep1($db, ["PMA_table2"]);
+        $result1 = $this->normalization->getHtmlFor3NFstep1($db, ['PMA_table2']);
         $this->assertEquals(
             '',
             $result1['subText']
@@ -565,7 +565,7 @@ class NormalizationTest extends TestCase
      */
     public function testFindPartialDependencies()
     {
-        $table = "PMA_table2";
+        $table = 'PMA_table2';
         $db = 'PMA_db';
         $result = $this->normalization->findPartialDependencies($table, $db);
         $this->assertStringContainsString(
diff --git a/test/classes/OperationsTest.php b/test/classes/OperationsTest.php
index a49ccf22b1..948c595aaf 100644
--- a/test/classes/OperationsTest.php
+++ b/test/classes/OperationsTest.php
@@ -66,7 +66,7 @@ class OperationsTest extends TestCase
 
         $this->assertRegExp(
             '/.*\/database\/operations(.|[\n])*Database comment.*name="comment"([\n]|.)*/m',
-            $this->operations->getHtmlForDatabaseComment("pma")
+            $this->operations->getHtmlForDatabaseComment('pma')
         );
     }
 
@@ -79,7 +79,7 @@ class OperationsTest extends TestCase
     {
 
         $db_collation = 'db1';
-        $html = $this->operations->getHtmlForRenameDatabase("pma", $db_collation);
+        $html = $this->operations->getHtmlForRenameDatabase('pma', $db_collation);
         $this->assertStringContainsString('index.php?route=/database/operations', $html);
         $this->assertRegExp(
             '/.*db_rename.*Rename database to.*/',
@@ -97,7 +97,7 @@ class OperationsTest extends TestCase
 
         $this->assertRegExp(
             '/.*DROP.DATABASE.*%2Fdatabase%2Foperations.*Drop the database.*/',
-            $this->operations->getHtmlForDropDatabaseLink("pma")
+            $this->operations->getHtmlForDropDatabaseLink('pma')
         );
     }
 
@@ -109,7 +109,7 @@ class OperationsTest extends TestCase
     public function testGetHtmlForCopyDatabase()
     {
         $db_collation = 'db1';
-        $html = $this->operations->getHtmlForCopyDatabase("pma", $db_collation);
+        $html = $this->operations->getHtmlForCopyDatabase('pma', $db_collation);
         $this->assertRegExp('/.*\/database\/operations.*/', $html);
         $this->assertRegExp('/.*db_copy.*/', $html);
         $this->assertRegExp('/.*Copy database to.*/', $html);
@@ -124,7 +124,7 @@ class OperationsTest extends TestCase
     {
 
         $db_collation = 'db1';
-        $result = $this->operations->getHtmlForChangeDatabaseCharset("pma", $db_collation);
+        $result = $this->operations->getHtmlForChangeDatabaseCharset('pma', $db_collation);
         $this->assertRegExp(
             '/.*select_db_collation.*Collation.*/m',
             $result
@@ -144,8 +144,8 @@ class OperationsTest extends TestCase
     {
         $actual = $this->operations->getHtmlForOrderTheTable(
             [
-                ['Field' => "column1"],
-                ['Field' => "column2"],
+                ['Field' => 'column1'],
+                ['Field' => 'column2'],
             ]
         );
         $this->assertStringContainsString(
@@ -222,8 +222,8 @@ class OperationsTest extends TestCase
         $this->assertRegExp(
             '/.*Delete data or table.*Empty the table.*Delete the table.*/m',
             $this->operations->getHtmlForDeleteDataOrTable(
-                ["truncate" => 'foo'],
-                ["drop" => 'bar']
+                ['truncate' => 'foo'],
+                ['drop' => 'bar']
             )
         );
     }
@@ -239,10 +239,10 @@ class OperationsTest extends TestCase
         $this->assertRegExp(
             '/.*TRUNCATE.TABLE.foo.*id_truncate.*Truncate table.*/m',
             $this->operations->getDeleteDataOrTablelink(
-                ["sql" => 'TRUNCATE TABLE foo'],
-                "TRUNCATE_TABLE",
-                "Truncate table",
-                "id_truncate"
+                ['sql' => 'TRUNCATE TABLE foo'],
+                'TRUNCATE_TABLE',
+                'Truncate table',
+                'id_truncate'
             )
         );
     }
@@ -256,12 +256,12 @@ class OperationsTest extends TestCase
     {
         $html = $this->operations->getHtmlForPartitionMaintenance(
             [
-                "partition1",
-                "partion2",
+                'partition1',
+                'partion2',
             ],
             [
-                "param1" => 'foo',
-                "param2" => 'bar',
+                'param1' => 'foo',
+                'param2' => 'bar',
             ]
         );
         $this->assertStringContainsString(
@@ -286,13 +286,13 @@ class OperationsTest extends TestCase
             [
                 [
                     'foreign_db' => 'db1',
-                    'foreign_table' => "foreign1",
-                    'foreign_field' => "foreign2",
+                    'foreign_table' => 'foreign1',
+                    'foreign_field' => 'foreign2',
                 ],
             ],
             [
-                "param1" => 'a',
-                "param2" => 'b',
+                'param1' => 'a',
+                'param2' => 'b',
             ]
         );
         $this->assertStringContainsString(
diff --git a/test/classes/Plugins/Auth/AuthenticationCookieTest.php b/test/classes/Plugins/Auth/AuthenticationCookieTest.php
index 891a647d0e..d71f8cfd3a 100644
--- a/test/classes/Plugins/Auth/AuthenticationCookieTest.php
+++ b/test/classes/Plugins/Auth/AuthenticationCookieTest.php
@@ -391,7 +391,7 @@ class AuthenticationCookieTest extends PmaTestCase
     {
         $GLOBALS['cfg']['CaptchaLoginPrivateKey'] = 'testprivkey';
         $GLOBALS['cfg']['CaptchaLoginPublicKey'] = 'testpubkey';
-        $_POST["g-recaptcha-response"] = '';
+        $_POST['g-recaptcha-response'] = '';
         $_POST['pma_username'] = 'testPMAUser';
 
         $this->assertFalse(
diff --git a/test/classes/Plugins/Auth/AuthenticationHttpTest.php b/test/classes/Plugins/Auth/AuthenticationHttpTest.php
index 00d8690e07..c670c753b3 100644
--- a/test/classes/Plugins/Auth/AuthenticationHttpTest.php
+++ b/test/classes/Plugins/Auth/AuthenticationHttpTest.php
@@ -38,8 +38,8 @@ class AuthenticationHttpTest extends PmaTestCase
         $GLOBALS['db'] = 'db';
         $GLOBALS['table'] = 'table';
         $GLOBALS['PMA_PHP_SELF'] = 'index.php';
-        $GLOBALS['lang'] = "en";
-        $GLOBALS['text_dir'] = "ltr";
+        $GLOBALS['lang'] = 'en';
+        $GLOBALS['text_dir'] = 'ltr';
         $GLOBALS['token_provided'] = true;
         $GLOBALS['token_mismatch'] = false;
         $this->object = new AuthenticationHttp();
diff --git a/test/classes/Plugins/Export/ExportCodegenTest.php b/test/classes/Plugins/Export/ExportCodegenTest.php
index 7075abd01a..27704f801b 100644
--- a/test/classes/Plugins/Export/ExportCodegenTest.php
+++ b/test/classes/Plugins/Export/ExportCodegenTest.php
@@ -68,16 +68,16 @@ class ExportCodegenTest extends PmaTestCase
 
         $this->assertEquals(
             [
-                "NHibernate C# DO",
-                "NHibernate XML",
+                'NHibernate C# DO',
+                'NHibernate XML',
             ],
             $attrCgFormats->getValue($this->object)
         );
 
         $this->assertEquals(
             [
-                "_handleNHibernateCSBody",
-                "_handleNHibernateXMLBody",
+                '_handleNHibernateCSBody',
+                '_handleNHibernateXMLBody',
             ],
             $attrCgHandlers->getValue($this->object)
         );
@@ -181,8 +181,8 @@ class ExportCodegenTest extends PmaTestCase
 
         $this->assertEquals(
             [
-                "NHibernate C# DO",
-                "NHibernate XML",
+                'NHibernate C# DO',
+                'NHibernate XML',
             ],
             $select->getValues()
         );
@@ -383,7 +383,7 @@ class ExportCodegenTest extends PmaTestCase
             "        #endregion\n" .
             "    }\n" .
             "    #endregion\n" .
-            "}",
+            '}',
             $result
         );
     }
diff --git a/test/classes/Plugins/Export/ExportCsvTest.php b/test/classes/Plugins/Export/ExportCsvTest.php
index ce2aaee4d6..7d13319abd 100644
--- a/test/classes/Plugins/Export/ExportCsvTest.php
+++ b/test/classes/Plugins/Export/ExportCsvTest.php
@@ -267,7 +267,7 @@ class ExportCsvTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            ";",
+            ';',
             $GLOBALS['csv_separator']
         );
 
@@ -302,7 +302,7 @@ class ExportCsvTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            ";",
+            ';',
             $GLOBALS['csv_separator']
         );
 
@@ -335,7 +335,7 @@ class ExportCsvTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            ",",
+            ',',
             $GLOBALS['csv_separator']
         );
 
@@ -607,7 +607,7 @@ class ExportCsvTest extends PmaTestCase
         $result = ob_get_clean();
 
         $this->assertEquals(
-            "\"foo\"bar;customNull;",
+            '"foo"bar;customNull;',
             $result
         );
 
@@ -661,7 +661,7 @@ class ExportCsvTest extends PmaTestCase
         $result = ob_get_clean();
 
         $this->assertEquals(
-            "\"foo\"\"bar;\"test\";",
+            '"foo""bar;"test";',
             $result
         );
 
@@ -768,7 +768,7 @@ class ExportCsvTest extends PmaTestCase
         $this->assertEquals(
             "\"foo#\"bar\"\"foo#\"bar;\"test\n" .
             "\"\"test\n" .
-            "\";",
+            '";',
             $result
         );
     }
diff --git a/test/classes/Plugins/Export/ExportExcelTest.php b/test/classes/Plugins/Export/ExportExcelTest.php
index b0099bc018..43b8ca2b7c 100644
--- a/test/classes/Plugins/Export/ExportExcelTest.php
+++ b/test/classes/Plugins/Export/ExportExcelTest.php
@@ -184,7 +184,7 @@ class ExportExcelTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            "Excel edition:",
+            'Excel edition:',
             $property->getText()
         );
 
diff --git a/test/classes/Plugins/Export/ExportHtmlwordTest.php b/test/classes/Plugins/Export/ExportHtmlwordTest.php
index ee00e12bc3..d8a27f2aaf 100644
--- a/test/classes/Plugins/Export/ExportHtmlwordTest.php
+++ b/test/classes/Plugins/Export/ExportHtmlwordTest.php
@@ -819,9 +819,9 @@ class ExportHtmlwordTest extends PmaTestCase
                 'db',
                 'tbl',
                 "\n",
-                "example.com",
-                "create_table",
-                "test"
+                'example.com',
+                'create_table',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -837,9 +837,9 @@ class ExportHtmlwordTest extends PmaTestCase
                 'db',
                 'tbl',
                 "\n",
-                "example.com",
-                "triggers",
-                "test"
+                'example.com',
+                'triggers',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -855,9 +855,9 @@ class ExportHtmlwordTest extends PmaTestCase
                 'db',
                 'tbl',
                 "\n",
-                "example.com",
-                "create_view",
-                "test"
+                'example.com',
+                'create_view',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -873,9 +873,9 @@ class ExportHtmlwordTest extends PmaTestCase
                 'db',
                 'tbl',
                 "\n",
-                "example.com",
-                "stand_in",
-                "test"
+                'example.com',
+                'stand_in',
+                'test'
             )
         );
         $result = ob_get_clean();
diff --git a/test/classes/Plugins/Export/ExportJsonTest.php b/test/classes/Plugins/Export/ExportJsonTest.php
index 7510e71c49..327b6d722c 100644
--- a/test/classes/Plugins/Export/ExportJsonTest.php
+++ b/test/classes/Plugins/Export/ExportJsonTest.php
@@ -271,7 +271,7 @@ class ExportJsonTest extends PmaTestCase
         );
 
         $this->assertTrue(
-            $this->object->exportData('db', 'tbl', "\n", "example.com", "SELECT")
+            $this->object->exportData('db', 'tbl', "\n", 'example.com', 'SELECT')
         );
     }
 }
diff --git a/test/classes/Plugins/Export/ExportLatexTest.php b/test/classes/Plugins/Export/ExportLatexTest.php
index 6dc1e7bc42..46fef85965 100644
--- a/test/classes/Plugins/Export/ExportLatexTest.php
+++ b/test/classes/Plugins/Export/ExportLatexTest.php
@@ -592,7 +592,7 @@ class ExportLatexTest extends PmaTestCase
 
         ob_start();
         $this->assertTrue(
-            $this->object->exportData('db', 'tbl', "\n", "example.com", "SELECT")
+            $this->object->exportData('db', 'tbl', "\n", 'example.com', 'SELECT')
         );
         $result = ob_get_clean();
 
@@ -648,7 +648,7 @@ class ExportLatexTest extends PmaTestCase
 
         ob_start();
         $this->assertTrue(
-            $this->object->exportData('db', 'tbl', "\n", "example.com", "SELECT")
+            $this->object->exportData('db', 'tbl', "\n", 'example.com', 'SELECT')
         );
         $result = ob_get_clean();
 
@@ -765,7 +765,7 @@ class ExportLatexTest extends PmaTestCase
                 'database',
                 '',
                 "\n",
-                "example.com",
+                'example.com',
                 'test',
                 'test',
                 true,
@@ -872,7 +872,7 @@ class ExportLatexTest extends PmaTestCase
                 'database',
                 '',
                 "\n",
-                "example.com",
+                'example.com',
                 'test',
                 'test',
                 true,
@@ -948,7 +948,7 @@ class ExportLatexTest extends PmaTestCase
                 'database',
                 '',
                 "\n",
-                "example.com",
+                'example.com',
                 'test',
                 'test'
             )
@@ -971,7 +971,7 @@ class ExportLatexTest extends PmaTestCase
                 'database',
                 '',
                 "\n",
-                "example.com",
+                'example.com',
                 'triggers',
                 'test'
             )
diff --git a/test/classes/Plugins/Export/ExportMediawikiTest.php b/test/classes/Plugins/Export/ExportMediawikiTest.php
index a1327c7c63..c13e439186 100644
--- a/test/classes/Plugins/Export/ExportMediawikiTest.php
+++ b/test/classes/Plugins/Export/ExportMediawikiTest.php
@@ -300,9 +300,9 @@ class ExportMediawikiTest extends PmaTestCase
                 'db',
                 'table',
                 "\n",
-                "example.com",
-                "create_table",
-                "test"
+                'example.com',
+                'create_table',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -389,8 +389,8 @@ class ExportMediawikiTest extends PmaTestCase
                 'db',
                 'table',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
         $result = ob_get_clean();
@@ -400,7 +400,7 @@ class ExportMediawikiTest extends PmaTestCase
             "Table data for `table`\n" .
             "-->\n" .
             "\n" .
-            "{| class=\"wikitable sortable\" style=\"text-align:" .
+            '{| class="wikitable sortable" style="text-align:' .
             "center;\"\n" .
             "|+'''table'''\n" .
             "|-\n" .
diff --git a/test/classes/Plugins/Export/ExportOdsTest.php b/test/classes/Plugins/Export/ExportOdsTest.php
index a0e14c17a7..e8d822fafe 100644
--- a/test/classes/Plugins/Export/ExportOdsTest.php
+++ b/test/classes/Plugins/Export/ExportOdsTest.php
@@ -308,7 +308,7 @@ class ExportOdsTest extends PmaTestCase
         $flags[] = $a;
 
         $a = new stdClass();
-        $a->type = "dummy";
+        $a->type = 'dummy';
         $a->blob = false;
         $a->numeric = false;
         $flags[] = $a;
@@ -351,10 +351,10 @@ class ExportOdsTest extends PmaTestCase
                         '01-01-2000',
                         '01-01-2000',
                         '01-01-2000 10:00:00',
-                        "01-01-2014 10:02:00",
-                        "t>s",
-                        "a&b",
-                        "<",
+                        '01-01-2014 10:02:00',
+                        't>s',
+                        'a&b',
+                        '<',
                     ]
                 )
             );
@@ -363,15 +363,15 @@ class ExportOdsTest extends PmaTestCase
         $GLOBALS['mediawiki_caption'] = true;
         $GLOBALS['mediawiki_headers'] = true;
         $GLOBALS['what'] = 'foo';
-        $GLOBALS['foo_null'] = "&";
+        $GLOBALS['foo_null'] = '&';
 
         $this->assertTrue(
             $this->object->exportData(
                 'db',
                 'table',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
 
@@ -463,7 +463,7 @@ class ExportOdsTest extends PmaTestCase
         $GLOBALS['mediawiki_caption'] = true;
         $GLOBALS['mediawiki_headers'] = true;
         $GLOBALS['what'] = 'foo';
-        $GLOBALS['foo_null'] = "&";
+        $GLOBALS['foo_null'] = '&';
         $GLOBALS['foo_columns'] = true;
 
         $this->assertTrue(
@@ -471,8 +471,8 @@ class ExportOdsTest extends PmaTestCase
                 'db',
                 'table',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
 
@@ -520,7 +520,7 @@ class ExportOdsTest extends PmaTestCase
         $GLOBALS['mediawiki_caption'] = true;
         $GLOBALS['mediawiki_headers'] = true;
         $GLOBALS['what'] = 'foo';
-        $GLOBALS['foo_null'] = "&";
+        $GLOBALS['foo_null'] = '&';
         $GLOBALS['ods_buffer'] = '';
 
         $this->assertTrue(
@@ -528,8 +528,8 @@ class ExportOdsTest extends PmaTestCase
                 'db',
                 'table',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
 
diff --git a/test/classes/Plugins/Export/ExportOdtTest.php b/test/classes/Plugins/Export/ExportOdtTest.php
index 98d05754dc..722901bffd 100644
--- a/test/classes/Plugins/Export/ExportOdtTest.php
+++ b/test/classes/Plugins/Export/ExportOdtTest.php
@@ -131,7 +131,7 @@ class ExportOdtTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            "Dump table",
+            'Dump table',
             $generalOptions->getText()
         );
 
@@ -319,11 +319,11 @@ class ExportOdtTest extends PmaTestCase
         );
 
         $this->assertStringContainsString(
-            "<office:document-content",
+            '<office:document-content',
             $GLOBALS['odt_buffer']
         );
         $this->assertStringContainsString(
-            "office:version",
+            'office:version',
             $GLOBALS['odt_buffer']
         );
     }
@@ -345,12 +345,12 @@ class ExportOdtTest extends PmaTestCase
         );
 
         $this->assertStringContainsString(
-            "header",
+            'header',
             $GLOBALS['odt_buffer']
         );
 
         $this->assertStringContainsString(
-            "</office:text></office:body></office:document-content>",
+            '</office:text></office:body></office:document-content>',
             $GLOBALS['odt_buffer']
         );
     }
@@ -369,12 +369,12 @@ class ExportOdtTest extends PmaTestCase
         );
 
         $this->assertStringContainsString(
-            "header",
+            'header',
             $GLOBALS['odt_buffer']
         );
 
         $this->assertStringContainsString(
-            "Database d&amp;b</text:h>",
+            'Database d&amp;b</text:h>',
             $GLOBALS['odt_buffer']
         );
     }
@@ -431,7 +431,7 @@ class ExportOdtTest extends PmaTestCase
         $flags[] = $a;
 
         $a = new stdClass();
-        $a->type = "timestamp";
+        $a->type = 'timestamp';
         $a->blob = false;
         $a->numeric = false;
         $flags[] = $a;
@@ -480,15 +480,15 @@ class ExportOdtTest extends PmaTestCase
 
         $GLOBALS['dbi'] = $dbi;
         $GLOBALS['what'] = 'foo';
-        $GLOBALS['foo_null'] = "&";
+        $GLOBALS['foo_null'] = '&';
 
         $this->assertTrue(
             $this->object->exportData(
                 'db',
                 'ta<ble',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
 
@@ -559,7 +559,7 @@ class ExportOdtTest extends PmaTestCase
 
         $GLOBALS['dbi'] = $dbi;
         $GLOBALS['what'] = 'foo';
-        $GLOBALS['foo_null'] = "&";
+        $GLOBALS['foo_null'] = '&';
         $GLOBALS['foo_columns'] = true;
 
         $this->assertTrue(
@@ -567,8 +567,8 @@ class ExportOdtTest extends PmaTestCase
                 'db',
                 'table',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
 
@@ -618,7 +618,7 @@ class ExportOdtTest extends PmaTestCase
         $GLOBALS['mediawiki_caption'] = true;
         $GLOBALS['mediawiki_headers'] = true;
         $GLOBALS['what'] = 'foo';
-        $GLOBALS['foo_null'] = "&";
+        $GLOBALS['foo_null'] = '&';
         $GLOBALS['odt_buffer'] = '';
 
         $this->assertTrue(
@@ -626,8 +626,8 @@ class ExportOdtTest extends PmaTestCase
                 'db',
                 'table',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
 
@@ -770,7 +770,7 @@ class ExportOdtTest extends PmaTestCase
                 'database',
                 '',
                 "\n",
-                "example.com",
+                'example.com',
                 true,
                 true,
                 true
@@ -873,7 +873,7 @@ class ExportOdtTest extends PmaTestCase
                 'database',
                 '',
                 "\n",
-                "example.com",
+                'example.com',
                 true,
                 true,
                 true
@@ -970,7 +970,7 @@ class ExportOdtTest extends PmaTestCase
 
         $this->object->expects($this->at(0))
             ->method('getTableDef')
-            ->with('db', 't&bl', "\n", "example.com", false, false, false, false)
+            ->with('db', 't&bl', "\n", 'example.com', false, false, false, false)
             ->will($this->returnValue('dumpText1'));
 
         $this->object->expects($this->once())
@@ -984,7 +984,7 @@ class ExportOdtTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
+                'example.com',
                 false,
                 false,
                 false,
@@ -1007,9 +1007,9 @@ class ExportOdtTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "create_table",
-                "test"
+                'example.com',
+                'create_table',
+                'test'
             )
         );
 
@@ -1027,9 +1027,9 @@ class ExportOdtTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "triggers",
-                "test"
+                'example.com',
+                'triggers',
+                'test'
             )
         );
 
@@ -1047,9 +1047,9 @@ class ExportOdtTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "create_view",
-                "test"
+                'example.com',
+                'create_view',
+                'test'
             )
         );
 
@@ -1066,9 +1066,9 @@ class ExportOdtTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "stand_in",
-                "test"
+                'example.com',
+                'stand_in',
+                'test'
             )
         );
 
diff --git a/test/classes/Plugins/Export/ExportPdfTest.php b/test/classes/Plugins/Export/ExportPdfTest.php
index 4ec471d96f..42297018ee 100644
--- a/test/classes/Plugins/Export/ExportPdfTest.php
+++ b/test/classes/Plugins/Export/ExportPdfTest.php
@@ -300,7 +300,7 @@ class ExportPdfTest extends PmaTestCase
                 'db',
                 'table',
                 "\n",
-                "phpmyadmin.net/err",
+                'phpmyadmin.net/err',
                 'SELECT'
             )
         );
@@ -338,7 +338,7 @@ class ExportPdfTest extends PmaTestCase
     {
         $setter = new ReflectionMethod('PhpMyAdmin\Plugins\Export\ExportPdf', '_setPdfReportTitle');
         $setter->setAccessible(true);
-        $setter->invoke($this->object, "title");
+        $setter->invoke($this->object, 'title');
 
         $getter = new ReflectionMethod('PhpMyAdmin\Plugins\Export\ExportPdf', '_getPdfReportTitle');
         $getter->setAccessible(true);
diff --git a/test/classes/Plugins/Export/ExportPhparrayTest.php b/test/classes/Plugins/Export/ExportPhparrayTest.php
index 3ee2e1d20e..a1ccfcf551 100644
--- a/test/classes/Plugins/Export/ExportPhparrayTest.php
+++ b/test/classes/Plugins/Export/ExportPhparrayTest.php
@@ -169,7 +169,7 @@ class ExportPhparrayTest extends PmaTestCase
 
         ob_start();
         $this->assertTrue(
-            $this->object->exportDBHeader("db")
+            $this->object->exportDBHeader('db')
         );
         $result = ob_get_clean();
 
diff --git a/test/classes/Plugins/Export/ExportSqlTest.php b/test/classes/Plugins/Export/ExportSqlTest.php
index bb355527fa..91766e212c 100644
--- a/test/classes/Plugins/Export/ExportSqlTest.php
+++ b/test/classes/Plugins/Export/ExportSqlTest.php
@@ -551,7 +551,7 @@ class ExportSqlTest extends PmaTestCase
         );
 
         $this->assertStringContainsString(
-            "40101 SET",
+            '40101 SET',
             $result
         );
 
@@ -674,7 +674,7 @@ class ExportSqlTest extends PmaTestCase
         $result = ob_get_clean();
 
         $this->assertStringContainsString(
-            "&quot;testDB&quot;",
+            '&quot;testDB&quot;',
             $result
         );
 
@@ -689,7 +689,7 @@ class ExportSqlTest extends PmaTestCase
         $result = ob_get_clean();
 
         $this->assertStringContainsString(
-            "testDB",
+            'testDB',
             $result
         );
     }
@@ -780,7 +780,7 @@ class ExportSqlTest extends PmaTestCase
     public function testExportDBFooter()
     {
         $GLOBALS['crlf'] = "\n";
-        $GLOBALS['sql_constraints'] = "SqlConstraints";
+        $GLOBALS['sql_constraints'] = 'SqlConstraints';
         $GLOBALS['sql_structure_or_data'] = 'structure';
         $GLOBALS['sql_procedure_function'] = true;
 
@@ -831,15 +831,15 @@ class ExportSqlTest extends PmaTestCase
 
         $GLOBALS['dbi'] = $dbi;
 
-        $result = $this->object->getTableDefStandIn('db', 'view', "");
+        $result = $this->object->getTableDefStandIn('db', 'view', '');
 
         $this->assertStringContainsString(
-            "DROP VIEW IF EXISTS `view`;",
+            'DROP VIEW IF EXISTS `view`;',
             $result
         );
 
         $this->assertStringContainsString(
-            "CREATE TABLE IF NOT EXISTS `view` (`cname` int);",
+            'CREATE TABLE IF NOT EXISTS `view` (`cname` int);',
             $result
         );
     }
@@ -1054,7 +1054,7 @@ class ExportSqlTest extends PmaTestCase
             'db',
             'table',
             "\n",
-            "example.com/err",
+            'example.com/err',
             true,
             true,
             false
@@ -1081,7 +1081,7 @@ class ExportSqlTest extends PmaTestCase
         );
 
         $this->assertStringContainsString(
-            "CREATE TABLE `table`",
+            'CREATE TABLE `table`',
             $result
         );
 
@@ -1212,7 +1212,7 @@ class ExportSqlTest extends PmaTestCase
             'db',
             'table',
             "\n",
-            "example.com/err",
+            'example.com/err',
             true,
             true,
             false
@@ -1285,14 +1285,14 @@ class ExportSqlTest extends PmaTestCase
         $this->assertStringContainsString(
             "-- MEDIA TYPES FOR TABLE :\n" .
             "--   fieldname\n" .
-            "--       Test<",
+            '--       Test<',
             $result
         );
 
         $this->assertStringContainsString(
             "-- RELATIONSHIPS FOR TABLE :\n" .
             "--   foo\n" .
-            "--       ftable -> ffield",
+            '--       ftable -> ffield',
             $result
         );
     }
@@ -1332,7 +1332,7 @@ class ExportSqlTest extends PmaTestCase
 
         $this->object->expects($this->at(0))
             ->method('getTableDef')
-            ->with('db', 't&bl', "\n", "example.com", false)
+            ->with('db', 't&bl', "\n", 'example.com', false)
             ->will($this->returnValue('dumpText1'));
 
         $this->object->expects($this->at(1))
@@ -1341,7 +1341,7 @@ class ExportSqlTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
+                'example.com',
                 false
             )
             ->will($this->returnValue('dumpText3'));
@@ -1364,9 +1364,9 @@ class ExportSqlTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "create_table",
-                "test"
+                'example.com',
+                'create_table',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -1394,9 +1394,9 @@ class ExportSqlTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "triggers",
-                "test"
+                'example.com',
+                'triggers',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -1423,9 +1423,9 @@ class ExportSqlTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "create_view",
-                "test"
+                'example.com',
+                'create_view',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -1437,7 +1437,7 @@ class ExportSqlTest extends PmaTestCase
 
         $this->assertStringContainsString(
             "DROP TABLE IF EXISTS `t&amp;bl`;\n" .
-            "dumpText3",
+            'dumpText3',
             $result
         );
 
@@ -1464,9 +1464,9 @@ class ExportSqlTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "create_view",
-                "test"
+                'example.com',
+                'create_view',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -1489,15 +1489,15 @@ class ExportSqlTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "stand_in",
-                "test"
+                'example.com',
+                'stand_in',
+                'test'
             )
         );
         $result = ob_get_clean();
 
         $this->assertStringContainsString(
-            "dumpText4",
+            'dumpText4',
             $result
         );
     }
@@ -1540,7 +1540,7 @@ class ExportSqlTest extends PmaTestCase
         $flags[] = $a;
 
         $a = new stdClass();
-        $a->type = "bit";
+        $a->type = 'bit';
         $a->blob = false;
         $a->numeric = false;
         $a->name = 'name';
@@ -1567,7 +1567,7 @@ class ExportSqlTest extends PmaTestCase
         $dbi->expects($this->once())
             ->method('tryQuery')
             ->with(
-                "SELECT a FROM b WHERE 1",
+                'SELECT a FROM b WHERE 1',
                 DatabaseInterface::CONNECT_USER,
                 DatabaseInterface::QUERY_UNBUFFERED
             )
@@ -1625,8 +1625,8 @@ class ExportSqlTest extends PmaTestCase
             'db',
             'table',
             "\n",
-            "example.com/err",
-            "SELECT a FROM b WHERE 1"
+            'example.com/err',
+            'SELECT a FROM b WHERE 1'
         );
         $result = ob_get_clean();
 
@@ -1653,7 +1653,7 @@ class ExportSqlTest extends PmaTestCase
         );
 
         $this->assertStringContainsString(
-            "SET IDENTITY_INSERT &quot;table&quot; OFF;",
+            'SET IDENTITY_INSERT &quot;table&quot; OFF;',
             $result
         );
     }
@@ -1706,7 +1706,7 @@ class ExportSqlTest extends PmaTestCase
         $dbi->expects($this->once())
             ->method('tryQuery')
             ->with(
-                "SELECT a FROM b WHERE 1",
+                'SELECT a FROM b WHERE 1',
                 DatabaseInterface::CONNECT_USER,
                 DatabaseInterface::QUERY_UNBUFFERED
             )
@@ -1760,8 +1760,8 @@ class ExportSqlTest extends PmaTestCase
             'db',
             'table',
             "\n",
-            "example.com/err",
-            "SELECT a FROM b WHERE 1"
+            'example.com/err',
+            'SELECT a FROM b WHERE 1'
         );
         $result = ob_get_clean();
 
@@ -1810,7 +1810,7 @@ class ExportSqlTest extends PmaTestCase
 
         ob_start();
         $this->assertTrue(
-            $this->object->exportData('db', 'tbl', "\n", "err.com", "SELECT")
+            $this->object->exportData('db', 'tbl', "\n", 'err.com', 'SELECT')
         );
         $result = ob_get_clean();
 
@@ -1867,7 +1867,7 @@ class ExportSqlTest extends PmaTestCase
 
         ob_start();
         $this->assertTrue(
-            $this->object->exportData('db', 'table', "\n", "err.com", "SELECT")
+            $this->object->exportData('db', 'table', "\n", 'err.com', 'SELECT')
         );
         $result = ob_get_clean();
 
@@ -2059,13 +2059,13 @@ class ExportSqlTest extends PmaTestCase
         $table = 'foo';
         $sql_query = "CREATE TABLE IF NOT EXISTS foo (\n"
             . "baz tinyint(3) unsigned NOT NULL COMMENT 'Primary Key',\n"
-            . "xyz varchar(255) COLLATE latin1_general_ci NOT NULL "
+            . 'xyz varchar(255) COLLATE latin1_general_ci NOT NULL '
             . "COMMENT 'xyz',\n"
-            . "pqr varchar(10) COLLATE latin1_general_ci NOT NULL "
+            . 'pqr varchar(10) COLLATE latin1_general_ci NOT NULL '
             . "COMMENT 'pqr',\n"
-            . "CONSTRAINT fk_om_dept FOREIGN KEY (baz) "
+            . 'CONSTRAINT fk_om_dept FOREIGN KEY (baz) '
             . "REFERENCES dept_master (baz)\n"
-            . ") ENGINE=InnoDB  DEFAULT CHARSET=latin1 COLLATE="
+            . ') ENGINE=InnoDB  DEFAULT CHARSET=latin1 COLLATE='
             . "latin1_general_ci COMMENT='List' AUTO_INCREMENT=5";
         $result = $this->object->replaceWithAliases(
             $sql_query,
@@ -2097,15 +2097,15 @@ class ExportSqlTest extends PmaTestCase
         );
 
         $table = 'bar';
-        $sql_query = "CREATE TRIGGER `BEFORE_bar_INSERT` "
-            . "BEFORE INSERT ON `bar` "
-            . "FOR EACH ROW BEGIN "
-            . "SET @cnt=(SELECT count(*) FROM bar WHERE "
-            . "xy=NEW.xy AND id=NEW.id AND "
-            . "abc=NEW.xy LIMIT 1); "
-            . "IF @cnt<>0 THEN "
-            . "SET NEW.xy=1; "
-            . "END IF; END";
+        $sql_query = 'CREATE TRIGGER `BEFORE_bar_INSERT` '
+            . 'BEFORE INSERT ON `bar` '
+            . 'FOR EACH ROW BEGIN '
+            . 'SET @cnt=(SELECT count(*) FROM bar WHERE '
+            . 'xy=NEW.xy AND id=NEW.id AND '
+            . 'abc=NEW.xy LIMIT 1); '
+            . 'IF @cnt<>0 THEN '
+            . 'SET NEW.xy=1; '
+            . 'END IF; END';
         $result = $this->object->replaceWithAliases(
             $sql_query,
             $aliases,
@@ -2114,12 +2114,12 @@ class ExportSqlTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            "CREATE TRIGGER `BEFORE_bar_INSERT` BEFORE INSERT ON `f` FOR EACH ROW BEGIN " .
-            "SET @cnt=(SELECT count(*) FROM `f` WHERE `n`=NEW.`n` AND id=NEW.id AND abc=NEW.`n` LIMIT 1); " .
-            "IF @cnt<>0 THEN " .
-            "SET NEW.`n`=1; " .
-            "END IF; " .
-            "END",
+            'CREATE TRIGGER `BEFORE_bar_INSERT` BEFORE INSERT ON `f` FOR EACH ROW BEGIN ' .
+            'SET @cnt=(SELECT count(*) FROM `f` WHERE `n`=NEW.`n` AND id=NEW.id AND abc=NEW.`n` LIMIT 1); ' .
+            'IF @cnt<>0 THEN ' .
+            'SET NEW.`n`=1; ' .
+            'END IF; ' .
+            'END',
             $result
         );
     }
diff --git a/test/classes/Plugins/Export/ExportTexytextTest.php b/test/classes/Plugins/Export/ExportTexytextTest.php
index 5487193644..4304549de4 100644
--- a/test/classes/Plugins/Export/ExportTexytextTest.php
+++ b/test/classes/Plugins/Export/ExportTexytextTest.php
@@ -116,7 +116,7 @@ class ExportTexytextTest extends PmaTestCase
         );
 
         $this->assertEquals(
-            "Dump table",
+            'Dump table',
             $generalOptions->getText()
         );
 
@@ -271,8 +271,8 @@ class ExportTexytextTest extends PmaTestCase
 
         $GLOBALS['dbi'] = $dbi;
         $GLOBALS['what'] = 'foo';
-        $GLOBALS['foo_columns'] = "&";
-        $GLOBALS['foo_null'] = ">";
+        $GLOBALS['foo_columns'] = '&';
+        $GLOBALS['foo_null'] = '>';
 
         ob_start();
         $this->assertTrue(
@@ -280,19 +280,19 @@ class ExportTexytextTest extends PmaTestCase
                 'db',
                 'ta<ble',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
         $result = ob_get_clean();
 
         $this->assertStringContainsString(
-            "|fName1|fNa&amp;quot;me2|fName3",
+            '|fName1|fNa&amp;quot;me2|fName3',
             $result
         );
 
         $this->assertStringContainsString(
-            "|&amp;gt;|0|test",
+            '|&amp;gt;|0|test',
             $result
         );
     }
@@ -450,7 +450,7 @@ class ExportTexytextTest extends PmaTestCase
             'db',
             'table',
             "\n",
-            "example.com",
+            'example.com',
             true,
             true,
             true
@@ -525,7 +525,7 @@ class ExportTexytextTest extends PmaTestCase
 
         $this->object->expects($this->at(0))
             ->method('getTableDef')
-            ->with('db', 't&bl', "\n", "example.com", false, false, false, false)
+            ->with('db', 't&bl', "\n", 'example.com', false, false, false, false)
             ->will($this->returnValue('dumpText1'));
 
         $this->object->expects($this->once())
@@ -539,7 +539,7 @@ class ExportTexytextTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
+                'example.com',
                 false,
                 false,
                 false,
@@ -563,9 +563,9 @@ class ExportTexytextTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "create_table",
-                "test"
+                'example.com',
+                'create_table',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -582,9 +582,9 @@ class ExportTexytextTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "triggers",
-                "test"
+                'example.com',
+                'triggers',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -601,9 +601,9 @@ class ExportTexytextTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "create_view",
-                "test"
+                'example.com',
+                'create_view',
+                'test'
             )
         );
         $result = ob_get_clean();
@@ -620,9 +620,9 @@ class ExportTexytextTest extends PmaTestCase
                 'db',
                 't&bl',
                 "\n",
-                "example.com",
-                "stand_in",
-                "test"
+                'example.com',
+                'stand_in',
+                'test'
             )
         );
         $result = ob_get_clean();
diff --git a/test/classes/Plugins/Export/ExportXmlTest.php b/test/classes/Plugins/Export/ExportXmlTest.php
index 285179081a..fd7f4e0a45 100644
--- a/test/classes/Plugins/Export/ExportXmlTest.php
+++ b/test/classes/Plugins/Export/ExportXmlTest.php
@@ -536,40 +536,40 @@ class ExportXmlTest extends PmaTestCase
                 'db',
                 'ta<ble',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
         $result = ob_get_clean();
 
         $this->assertStringContainsString(
-            "<!-- Table ta&lt;ble -->",
+            '<!-- Table ta&lt;ble -->',
             $result
         );
 
         $this->assertStringContainsString(
-            "<table name=\"ta&lt;ble\">",
+            '<table name="ta&lt;ble">',
             $result
         );
 
         $this->assertStringContainsString(
-            "<column name=\"fName1\">NULL</column>",
+            '<column name="fName1">NULL</column>',
             $result
         );
 
         $this->assertStringContainsString(
-            "<column name=\"fNa&quot;me2\">&lt;a&gt;" .
-            "</column>",
+            '<column name="fNa&quot;me2">&lt;a&gt;' .
+            '</column>',
             $result
         );
 
         $this->assertStringContainsString(
-            "<column name=\"fName3\">NULL</column>",
+            '<column name="fName3">NULL</column>',
             $result
         );
 
         $this->assertStringContainsString(
-            "</table>",
+            '</table>',
             $result
         );
     }
diff --git a/test/classes/Plugins/Export/ExportYamlTest.php b/test/classes/Plugins/Export/ExportYamlTest.php
index 75e454ee90..538f954062 100644
--- a/test/classes/Plugins/Export/ExportYamlTest.php
+++ b/test/classes/Plugins/Export/ExportYamlTest.php
@@ -259,8 +259,8 @@ class ExportYamlTest extends PmaTestCase
                 'db',
                 'ta<ble',
                 "\n",
-                "example.com",
-                "SELECT"
+                'example.com',
+                'SELECT'
             )
         );
         $result = ob_get_clean();
diff --git a/test/classes/Plugins/Export/Helpers/TablePropertyTest.php b/test/classes/Plugins/Export/Helpers/TablePropertyTest.php
index 8b72b806d1..6ac273e7b0 100644
--- a/test/classes/Plugins/Export/Helpers/TablePropertyTest.php
+++ b/test/classes/Plugins/Export/Helpers/TablePropertyTest.php
@@ -94,17 +94,17 @@ class TablePropertyTest extends PmaTestCase
      */
     public function testGetPureType()
     {
-        $this->object->type = "int(10)";
+        $this->object->type = 'int(10)';
 
         $this->assertEquals(
-            "int",
+            'int',
             $this->object->getPureType()
         );
 
-        $this->object->type = "char";
+        $this->object->type = 'char';
 
         $this->assertEquals(
-            "char",
+            'char',
             $this->object->getPureType()
         );
     }
@@ -137,16 +137,16 @@ class TablePropertyTest extends PmaTestCase
     {
         return [
             [
-                "NO",
-                "true",
+                'NO',
+                'true',
             ],
             [
-                "",
-                "false",
+                '',
+                'false',
             ],
             [
-                "no",
-                "false",
+                'no',
+                'false',
             ],
         ];
     }
@@ -179,24 +179,24 @@ class TablePropertyTest extends PmaTestCase
     {
         return [
             [
-                "PRI",
-                "true",
+                'PRI',
+                'true',
             ],
             [
-                "UNI",
-                "true",
+                'UNI',
+                'true',
             ],
             [
-                "",
-                "false",
+                '',
+                'false',
             ],
             [
-                "pri",
-                "false",
+                'pri',
+                'false',
             ],
             [
-                "uni",
-                "false",
+                'uni',
+                'false',
             ],
         ];
     }
@@ -229,48 +229,48 @@ class TablePropertyTest extends PmaTestCase
     {
         return [
             [
-                "int",
-                "int",
+                'int',
+                'int',
             ],
             [
-                "long",
-                "long",
+                'long',
+                'long',
             ],
             [
-                "char",
-                "string",
+                'char',
+                'string',
             ],
             [
-                "varchar",
-                "string",
+                'varchar',
+                'string',
             ],
             [
-                "text",
-                "string",
+                'text',
+                'string',
             ],
             [
-                "longtext",
-                "string",
+                'longtext',
+                'string',
             ],
             [
-                "tinyint",
-                "bool",
+                'tinyint',
+                'bool',
             ],
             [
-                "datetime",
-                "DateTime",
+                'datetime',
+                'DateTime',
             ],
             [
-                "",
-                "unknown",
+                '',
+                'unknown',
             ],
             [
-                "dummy",
-                "unknown",
+                'dummy',
+                'unknown',
             ],
             [
-                "INT",
-                "unknown",
+                'INT',
+                'unknown',
             ],
         ];
     }
@@ -303,48 +303,48 @@ class TablePropertyTest extends PmaTestCase
     {
         return [
             [
-                "int",
-                "Int32",
+                'int',
+                'Int32',
             ],
             [
-                "long",
-                "Long",
+                'long',
+                'Long',
             ],
             [
-                "char",
-                "String",
+                'char',
+                'String',
             ],
             [
-                "varchar",
-                "String",
+                'varchar',
+                'String',
             ],
             [
-                "text",
-                "String",
+                'text',
+                'String',
             ],
             [
-                "longtext",
-                "String",
+                'longtext',
+                'String',
             ],
             [
-                "tinyint",
-                "Boolean",
+                'tinyint',
+                'Boolean',
             ],
             [
-                "datetime",
-                "DateTime",
+                'datetime',
+                'DateTime',
             ],
             [
-                "",
-                "Unknown",
+                '',
+                'Unknown',
             ],
             [
-                "dummy",
-                "Unknown",
+                'dummy',
+                'Unknown',
             ],
             [
-                "INT",
-                "Unknown",
+                'INT',
+                'Unknown',
             ],
         ];
     }
@@ -357,17 +357,17 @@ class TablePropertyTest extends PmaTestCase
     public function testGetIndexName()
     {
         $this->object->name = "ä'7<ab>";
-        $this->object->key = "PRI";
+        $this->object->key = 'PRI';
 
         $this->assertEquals(
             "index=\"ä'7&lt;ab&gt;\"",
             $this->object->getIndexName()
         );
 
-        $this->object->key = "";
+        $this->object->key = '';
 
         $this->assertEquals(
-            "",
+            '',
             $this->object->getIndexName()
         );
     }
@@ -379,13 +379,13 @@ class TablePropertyTest extends PmaTestCase
      */
     public function testIsPK()
     {
-        $this->object->key = "PRI";
+        $this->object->key = 'PRI';
 
         $this->assertTrue(
             $this->object->isPK()
         );
 
-        $this->object->key = "";
+        $this->object->key = '';
 
         $this->assertFalse(
             $this->object->isPK()
@@ -403,7 +403,7 @@ class TablePropertyTest extends PmaTestCase
 
         $this->assertEquals(
             'text123Namename',
-            $this->object->formatCs("text123#name#")
+            $this->object->formatCs('text123#name#')
         );
     }
 
@@ -418,7 +418,7 @@ class TablePropertyTest extends PmaTestCase
 
         $this->assertEquals(
             '&quot;a\'index="&quot;a\'"',
-            $this->object->formatXml("#name##indexName#")
+            $this->object->formatXml('#name##indexName#')
         );
     }
 
@@ -432,8 +432,8 @@ class TablePropertyTest extends PmaTestCase
         $this->assertEquals(
             'NameintInt32intfalsetrue',
             $this->object->format(
-                "#ucfirstName##dotNetPrimitiveType##dotNetObjectType##type#" .
-                "#notNull##unique#"
+                '#ucfirstName##dotNetPrimitiveType##dotNetObjectType##type#' .
+                '#notNull##unique#'
             )
         );
     }
diff --git a/test/classes/Plugins/Import/ImportCsvTest.php b/test/classes/Plugins/Import/ImportCsvTest.php
index c35d2e1f95..7b39186284 100644
--- a/test/classes/Plugins/Import/ImportCsvTest.php
+++ b/test/classes/Plugins/Import/ImportCsvTest.php
@@ -36,7 +36,7 @@ class ImportCsvTest extends PmaTestCase
     protected function setUp(): void
     {
         $GLOBALS['server'] = 0;
-        $GLOBALS['plugin_param'] = "csv";
+        $GLOBALS['plugin_param'] = 'csv';
         $this->object = new ImportCsv();
 
         unset($GLOBALS['db']);
@@ -60,7 +60,7 @@ class ImportCsvTest extends PmaTestCase
         $GLOBALS['csv_enclosed'] = '"';
         $GLOBALS['csv_escaped'] = '"';
         $GLOBALS['csv_new_line'] = 'auto';
-        $GLOBALS['import_file_name'] = basename($GLOBALS['import_file'], ".csv");
+        $GLOBALS['import_file_name'] = basename($GLOBALS['import_file'], '.csv');
 
         //$_SESSION
 
diff --git a/test/classes/Plugins/Import/ImportLdiTest.php b/test/classes/Plugins/Import/ImportLdiTest.php
index 50d48d8c7f..87a6b4773e 100644
--- a/test/classes/Plugins/Import/ImportLdiTest.php
+++ b/test/classes/Plugins/Import/ImportLdiTest.php
@@ -65,7 +65,7 @@ class ImportLdiTest extends PmaTestCase
         $GLOBALS['cfg']['Import']['ldi_new_line'] = 'auto';
         $GLOBALS['cfg']['Import']['ldi_columns'] = '';
         $GLOBALS['cfg']['Import']['ldi_local_option'] = false;
-        $GLOBALS['table'] = "phpmyadmintest";
+        $GLOBALS['table'] = 'phpmyadmintest';
 
         //Mock DBI
         $this->dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
@@ -127,7 +127,7 @@ class ImportLdiTest extends PmaTestCase
         $dbi->expects($this->any())->method('numRows')
             ->will($this->returnValue(10));
 
-        $fetchRowResult = ["ON"];
+        $fetchRowResult = ['ON'];
         $dbi->expects($this->any())->method('fetchRow')
             ->will($this->returnValue($fetchRowResult));
 
@@ -177,7 +177,7 @@ class ImportLdiTest extends PmaTestCase
         //asset that all sql are executed
         $this->assertStringContainsString(
             "LOAD DATA INFILE 'test/test_data/db_test_ldi.csv' INTO TABLE "
-            . "`phpmyadmintest`",
+            . '`phpmyadmintest`',
             $sql_query
         );
 
@@ -253,7 +253,7 @@ class ImportLdiTest extends PmaTestCase
         //replace
         $this->assertStringContainsString(
             "LOAD DATA LOCAL INFILE 'test/test_data/db_test_ldi.csv' REPLACE INTO "
-            . "TABLE `phpmyadmintest`",
+            . 'TABLE `phpmyadmintest`',
             $sql_query
         );
 
@@ -271,7 +271,7 @@ class ImportLdiTest extends PmaTestCase
 
         //IGNORE
         $this->assertStringContainsString(
-            "IGNORE 1 LINES",
+            'IGNORE 1 LINES',
             $sql_query
         );
 
diff --git a/test/classes/Plugins/Import/ImportOdsTest.php b/test/classes/Plugins/Import/ImportOdsTest.php
index 75a91928a4..44c7142d98 100644
--- a/test/classes/Plugins/Import/ImportOdsTest.php
+++ b/test/classes/Plugins/Import/ImportOdsTest.php
@@ -34,7 +34,7 @@ class ImportOdsTest extends PmaTestCase
     protected function setUp(): void
     {
         $GLOBALS['server'] = 0;
-        $GLOBALS['plugin_param'] = "csv";
+        $GLOBALS['plugin_param'] = 'csv';
         $this->object = new ImportOds();
 
         //setting
@@ -131,7 +131,7 @@ class ImportOdsTest extends PmaTestCase
             $sql_query
         );
         $this->assertStringContainsString(
-            "INSERT INTO `ODS_DB`.`pma_bookmark` (`A`, `B`, `C`, `D`) VALUES "
+            'INSERT INTO `ODS_DB`.`pma_bookmark` (`A`, `B`, `C`, `D`) VALUES '
             . "(1, 'dbbase', NULL, 'ddd');",
             $sql_query
         );
diff --git a/test/classes/Plugins/Import/ImportShpTest.php b/test/classes/Plugins/Import/ImportShpTest.php
index b393507ccd..9a3bb56706 100644
--- a/test/classes/Plugins/Import/ImportShpTest.php
+++ b/test/classes/Plugins/Import/ImportShpTest.php
@@ -140,10 +140,10 @@ class ImportShpTest extends PmaTestCase
         $this->assertMessages($import_notice);
         $this->assertStringContainsString(
             "(GeomFromText('MULTIPOLYGON((("
-            . "13.737122 51.0542065,"
-            . "13.7373039 51.0541298,"
-            . "13.7372661 51.0540944,"
-            . "13.7370842 51.0541711,"
+            . '13.737122 51.0542065,'
+            . '13.7373039 51.0541298,'
+            . '13.7372661 51.0540944,'
+            . '13.7370842 51.0541711,'
             . "13.737122 51.0542065)))'))",
             $sql_query
         );
@@ -179,7 +179,7 @@ class ImportShpTest extends PmaTestCase
             $sql_query
         );
         $this->assertStringContainsString(
-            "INSERT INTO `SHP_DB`.`TBL_NAME` (`SPATIAL`) VALUES",
+            'INSERT INTO `SHP_DB`.`TBL_NAME` (`SPATIAL`) VALUES',
             $sql_query
         );
         $this->assertStringContainsString(
diff --git a/test/classes/Plugins/Schema/DiaRelationSchemaTest.php b/test/classes/Plugins/Schema/DiaRelationSchemaTest.php
index 009c64b494..dc6c0c0a5e 100644
--- a/test/classes/Plugins/Schema/DiaRelationSchemaTest.php
+++ b/test/classes/Plugins/Schema/DiaRelationSchemaTest.php
@@ -46,14 +46,14 @@ class DiaRelationSchemaTest extends PmaTestCase
 
         $GLOBALS['server'] = 1;
         $GLOBALS['db'] = 'information_schema';
-        $GLOBALS['cfg']['Server']['table_coords'] = "table_name";
+        $GLOBALS['cfg']['Server']['table_coords'] = 'table_name';
 
         //_SESSION
         $_SESSION['relation'][$GLOBALS['server']] = [
             'PMA_VERSION' => PMA_VERSION,
-            'table_coords' => "table_name",
+            'table_coords' => 'table_name',
             'displaywork' => 'displaywork',
-            'db' => "information_schema",
+            'db' => 'information_schema',
             'table_info' => 'table_info',
             'relwork' => 'relwork',
             'relation' => 'relation',
@@ -71,11 +71,11 @@ class DiaRelationSchemaTest extends PmaTestCase
 
         $dbi->expects($this->any())
             ->method('query')
-            ->will($this->returnValue("executed_1"));
+            ->will($this->returnValue('executed_1'));
 
         $dbi->expects($this->any())
             ->method('tryQuery')
-            ->will($this->returnValue("executed_1"));
+            ->will($this->returnValue('executed_1'));
 
         $fetchArrayReturn = [
             //table name in information_schema_relations
@@ -102,8 +102,8 @@ class DiaRelationSchemaTest extends PmaTestCase
                 'Table' => 'pma_tbl',
                 'Field' => 'field1',
                 'Key' => 'PRIMARY',
-                'Key_name' => "Key_name",
-                'Column_name' => "Column_name",
+                'Key_name' => 'Key_name',
+                'Column_name' => 'Column_name',
             ],
         ];
         $dbi->expects($this->any())->method('getTableIndexes')
diff --git a/test/classes/Plugins/Schema/EpsRelationSchemaTest.php b/test/classes/Plugins/Schema/EpsRelationSchemaTest.php
index 24baf98196..b472ad468a 100644
--- a/test/classes/Plugins/Schema/EpsRelationSchemaTest.php
+++ b/test/classes/Plugins/Schema/EpsRelationSchemaTest.php
@@ -47,14 +47,14 @@ class EpsRelationSchemaTest extends PmaTestCase
 
         $GLOBALS['server'] = 1;
         $GLOBALS['db'] = 'information_schema';
-        $GLOBALS['cfg']['Server']['table_coords'] = "table_name";
+        $GLOBALS['cfg']['Server']['table_coords'] = 'table_name';
 
         //_SESSION
         $_SESSION['relation'][$GLOBALS['server']] = [
             'PMA_VERSION' => PMA_VERSION,
-            'table_coords' => "table_name",
+            'table_coords' => 'table_name',
             'displaywork' => 'displaywork',
-            'db' => "information_schema",
+            'db' => 'information_schema',
             'table_info' => 'table_info',
             'relwork' => 'relwork',
             'relation' => 'relation',
@@ -72,11 +72,11 @@ class EpsRelationSchemaTest extends PmaTestCase
 
         $dbi->expects($this->any())
             ->method('query')
-            ->will($this->returnValue("executed_1"));
+            ->will($this->returnValue('executed_1'));
 
         $dbi->expects($this->any())
             ->method('tryQuery')
-            ->will($this->returnValue("executed_1"));
+            ->will($this->returnValue('executed_1'));
 
         $fetchArrayReturn = [
             //table name in information_schema_relations
@@ -103,8 +103,8 @@ class EpsRelationSchemaTest extends PmaTestCase
                 'Table' => 'pma_tbl',
                 'Field' => 'field1',
                 'Key' => 'PRIMARY',
-                'Key_name' => "Key_name",
-                'Column_name' => "Column_name",
+                'Key_name' => 'Key_name',
+                'Column_name' => 'Column_name',
             ],
         ];
         $dbi->expects($this->any())->method('getTableIndexes')
diff --git a/test/classes/Plugins/Schema/PdfRelationSchemaTest.php b/test/classes/Plugins/Schema/PdfRelationSchemaTest.php
index cda60ab44e..ad43bd358e 100644
--- a/test/classes/Plugins/Schema/PdfRelationSchemaTest.php
+++ b/test/classes/Plugins/Schema/PdfRelationSchemaTest.php
@@ -50,19 +50,19 @@ class PdfRelationSchemaTest extends PmaTestCase
 
         $GLOBALS['server'] = 1;
         $GLOBALS['db'] = 'information_schema';
-        $GLOBALS['cfg']['Server']['pmadb'] = "pmadb";
-        $GLOBALS['cfg']['Server']['user'] = "user";
-        $GLOBALS['cfg']['Server']['table_coords'] = "table_name";
-        $GLOBALS['cfg']['Server']['bookmarktable'] = "bookmarktable";
-        $GLOBALS['cfg']['Server']['relation'] = "relation";
-        $GLOBALS['cfg']['Server']['table_info'] = "table_info";
+        $GLOBALS['cfg']['Server']['pmadb'] = 'pmadb';
+        $GLOBALS['cfg']['Server']['user'] = 'user';
+        $GLOBALS['cfg']['Server']['table_coords'] = 'table_name';
+        $GLOBALS['cfg']['Server']['bookmarktable'] = 'bookmarktable';
+        $GLOBALS['cfg']['Server']['relation'] = 'relation';
+        $GLOBALS['cfg']['Server']['table_info'] = 'table_info';
 
         //_SESSION
         $_SESSION['relation'][$GLOBALS['server']] = [
             'PMA_VERSION' => PMA_VERSION,
-            'table_coords' => "table_name",
+            'table_coords' => 'table_name',
             'displaywork' => 'displaywork',
-            'db' => "information_schema",
+            'db' => 'information_schema',
             'table_info' => 'table_info',
             'relwork' => false,
             'relation' => 'relation',
@@ -84,11 +84,11 @@ class PdfRelationSchemaTest extends PmaTestCase
 
         $dbi->expects($this->any())
             ->method('query')
-            ->will($this->returnValue("executed_1"));
+            ->will($this->returnValue('executed_1'));
 
         $dbi->expects($this->any())
             ->method('tryQuery')
-            ->will($this->returnValue("executed_1"));
+            ->will($this->returnValue('executed_1'));
 
         $fetchArrayReturn = [
             //table name in information_schema_relations
@@ -123,11 +123,11 @@ class PdfRelationSchemaTest extends PmaTestCase
         }
 
         $fields_info = [
-            "Host" => [
-                "Field" => "host",
-                "Type" => "char(60)",
-                "Null" => "NO",
-                'Extra' => "Extra",
+            'Host' => [
+                'Field' => 'host',
+                'Type' => 'char(60)',
+                'Null' => 'NO',
+                'Extra' => 'Extra',
             ],
         ];
         $dbi->expects($this->any())->method('getColumns')
@@ -141,8 +141,8 @@ class PdfRelationSchemaTest extends PmaTestCase
                 'Table' => 'pma_tbl',
                 'Field' => 'field1',
                 'Key' => 'PRIMARY',
-                'Key_name' => "Key_name",
-                'Column_name' => "Column_name",
+                'Key_name' => 'Key_name',
+                'Column_name' => 'Column_name',
             ],
         ];
         $dbi->expects($this->any())->method('getTableIndexes')
diff --git a/test/classes/Plugins/Schema/SvgRelationSchemaTest.php b/test/classes/Plugins/Schema/SvgRelationSchemaTest.php
index 78beaad195..54d2ff5d47 100644
--- a/test/classes/Plugins/Schema/SvgRelationSchemaTest.php
+++ b/test/classes/Plugins/Schema/SvgRelationSchemaTest.php
@@ -46,14 +46,14 @@ class SvgRelationSchemaTest extends PmaTestCase
 
         $GLOBALS['server'] = 1;
         $GLOBALS['db'] = 'information_schema';
-        $GLOBALS['cfg']['Server']['table_coords'] = "table_name";
+        $GLOBALS['cfg']['Server']['table_coords'] = 'table_name';
 
         //_SESSION
         $_SESSION['relation'][$GLOBALS['server']] = [
             'PMA_VERSION' => PMA_VERSION,
-            'table_coords' => "table_name",
+            'table_coords' => 'table_name',
             'displaywork' => 'displaywork',
-            'db' => "information_schema",
+            'db' => 'information_schema',
             'table_info' => 'table_info',
             'relwork' => 'relwork',
             'relation' => 'relation',
@@ -71,11 +71,11 @@ class SvgRelationSchemaTest extends PmaTestCase
 
         $dbi->expects($this->any())
             ->method('query')
-            ->will($this->returnValue("executed_1"));
+            ->will($this->returnValue('executed_1'));
 
         $dbi->expects($this->any())
             ->method('tryQuery')
-            ->will($this->returnValue("executed_1"));
+            ->will($this->returnValue('executed_1'));
 
         $fetchArrayReturn = [
             //table name in information_schema_relations
@@ -102,8 +102,8 @@ class SvgRelationSchemaTest extends PmaTestCase
                 'Table' => 'pma_tbl',
                 'Field' => 'field1',
                 'Key' => 'PRIMARY',
-                'Key_name' => "Key_name",
-                'Column_name' => "Column_name",
+                'Key_name' => 'Key_name',
+                'Column_name' => 'Column_name',
             ],
         ];
         $dbi->expects($this->any())->method('getTableIndexes')
diff --git a/test/classes/Plugins/Transformations/TransformationPluginsTest.php b/test/classes/Plugins/Transformations/TransformationPluginsTest.php
index 4048058471..b861189fa2 100644
--- a/test/classes/Plugins/Transformations/TransformationPluginsTest.php
+++ b/test/classes/Plugins/Transformations/TransformationPluginsTest.php
@@ -49,8 +49,8 @@ class TransformationPluginsTest extends PmaTestCase
         global $row, $fields_meta;
         $fields_meta = [];
         $row = [
-            "pma" => "aaa",
-            "pca" => "bbb",
+            'pma' => 'aaa',
+            'pca' => 'bbb',
         ];
 
         // For Image_*_Inline plugin
@@ -438,8 +438,8 @@ class TransformationPluginsTest extends PmaTestCase
                 true,
                 [
                     [
-                        "/dev/null -i -wrap -q",
-                        "/dev/null -i -wrap -q",
+                        '/dev/null -i -wrap -q',
+                        '/dev/null -i -wrap -q',
                     ],
                 ],
             ],
@@ -449,9 +449,9 @@ class TransformationPluginsTest extends PmaTestCase
                 true,
                 [
                     [
-                        "/dev/null -i -wrap -q",
-                        "/dev/null -i -wrap -q",
-                        "/dev/null -i -wrap -q",
+                        '/dev/null -i -wrap -q',
+                        '/dev/null -i -wrap -q',
+                        '/dev/null -i -wrap -q',
                         1,
                     ],
                 ],
@@ -462,10 +462,10 @@ class TransformationPluginsTest extends PmaTestCase
                 true,
                 [
                     [
-                        "/dev/null -i -wrap -q",
-                        "/dev/null -i -wrap -q",
-                        "/dev/null -i -wrap -q",
-                        "1",
+                        '/dev/null -i -wrap -q',
+                        '/dev/null -i -wrap -q',
+                        '/dev/null -i -wrap -q',
+                        '1',
                     ],
                 ],
             ],
@@ -475,9 +475,9 @@ class TransformationPluginsTest extends PmaTestCase
                 false,
                 [
                     [
-                        "/dev/null -i -wrap -q",
-                        "/dev/null -i -wrap -q",
-                        "/dev/null -i -wrap -q",
+                        '/dev/null -i -wrap -q',
+                        '/dev/null -i -wrap -q',
+                        '/dev/null -i -wrap -q',
                         2,
                     ],
                 ],
@@ -784,7 +784,7 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_BUFFER',
                     [
-                        0 => "filename",
+                        0 => 'filename',
                         'wrapper_link' => 'PMA_wrapper_link',
                         'wrapper_params' => ['key' => 'value'],
                     ],
@@ -798,7 +798,7 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_BUFFER',
                     [
-                        0 => "",
+                        0 => '',
                         1 => 'cloumn',
                         'wrapper_link' => 'PMA_wrapper_link',
                         'wrapper_params' => ['key' => 'value'],
@@ -837,9 +837,9 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_IMAGE_LINK',
                     [
-                        0 => "./image/",
-                        1 => "200",
-                        "wrapper_link" => "PMA_wrapper_link",
+                        0 => './image/',
+                        1 => '200',
+                        'wrapper_link' => 'PMA_wrapper_link',
                         'wrapper_params' => ['key' => 'value'],
                     ],
                 ],
@@ -900,8 +900,8 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_BUFFER',
                     [
-                        "/dev/null -i -wrap -q",
-                        "/dev/null -i -wrap -q",
+                        '/dev/null -i -wrap -q',
+                        '/dev/null -i -wrap -q',
                     ],
                 ],
                 'PMA_BUFFER',
@@ -911,8 +911,8 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     "<a ref='https://www.example.com/'>PMA_BUFFER</a>",
                     [
-                        "option1",
-                        "option2",
+                        'option1',
+                        'option2',
                     ],
                 ],
                 "<iframe srcdoc=\"<a ref='https://www.example.com/'>PMA_BUFFER</a>\" sandbox=\"\"></iframe>",
@@ -920,10 +920,10 @@ class TransformationPluginsTest extends PmaTestCase
             [
                 new Text_Plain_Formatted(),
                 [
-                    "<a ref=\"https://www.example.com/\">PMA_BUFFER</a>",
+                    '<a ref="https://www.example.com/">PMA_BUFFER</a>',
                     [
-                        "option1",
-                        "option2",
+                        'option1',
+                        'option2',
                     ],
                 ],
                 "<iframe srcdoc=\"<a ref='https://www.example.com/'>PMA_BUFFER</a>\" sandbox=\"\"></iframe>",
@@ -933,8 +933,8 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_IMAGE',
                     [
-                        "http://image/",
-                        "200",
+                        'http://image/',
+                        '200',
                     ],
                 ],
                 '<a href="http://image/PMA_IMAGE" rel="noopener noreferrer" target="_blank">
@@ -948,8 +948,8 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_IMAGE',
                     [
-                        "./image/",
-                        "200",
+                        './image/',
+                        '200',
                     ],
                 ],
                 './image/PMA_IMAGE',
@@ -959,8 +959,8 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'select *',
                     [
-                        "option1",
-                        "option2",
+                        'option1',
+                        'option2',
                     ],
                 ],
                 '<code class="sql"><pre>' . "\n"
@@ -972,8 +972,8 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_TXT_LINK',
                     [
-                        "./php/",
-                        "text_name",
+                        './php/',
+                        'text_name',
                     ],
                 ],
                 './php/PMA_TXT_LINK',
@@ -1000,8 +1000,8 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_TXT_LINK',
                     [
-                        "./php/",
-                        "text_name",
+                        './php/',
+                        'text_name',
                     ],
                 ],
                 './php/PMA_TXT_LINK',
@@ -1011,8 +1011,8 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     42949672,
                     [
-                        "option1",
-                        "option2",
+                        'option1',
+                        'option2',
                     ],
                 ],
                 '2.143.92.40',
@@ -1022,8 +1022,8 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     4294967295,
                     [
-                        "option1",
-                        "option2",
+                        'option1',
+                        'option2',
                     ],
                 ],
                 '255.255.255.255',
@@ -1079,9 +1079,9 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_JPEG_Inline',
                     [
-                        0 => "./image/",
-                        1 => "200",
-                        "wrapper_link" => "PMA_wrapper_link",
+                        0 => './image/',
+                        1 => '200',
+                        'wrapper_link' => 'PMA_wrapper_link',
                         'wrapper_params' => ['key' => 'value'],
                     ],
                 ],
@@ -1095,9 +1095,9 @@ class TransformationPluginsTest extends PmaTestCase
                 [
                     'PMA_PNG_Inline',
                     [
-                        0 => "./image/",
-                        1 => "200",
-                        "wrapper_link" => "PMA_wrapper_link",
+                        0 => './image/',
+                        1 => '200',
+                        'wrapper_link' => 'PMA_wrapper_link',
                         'wrapper_params' => ['key' => 'value'],
                     ],
                 ],
diff --git a/test/classes/Properties/Options/Items/PropertyItemsTest.php b/test/classes/Properties/Options/Items/PropertyItemsTest.php
index 9c7151dded..f49d2693d4 100644
--- a/test/classes/Properties/Options/Items/PropertyItemsTest.php
+++ b/test/classes/Properties/Options/Items/PropertyItemsTest.php
@@ -34,14 +34,14 @@ class PropertyItemsTest extends TestCase
         $object = new BoolPropertyItem(null, 'Text');
 
         $this->assertEquals(
-            "Text",
+            'Text',
             $object->getText()
         );
 
         $object->setText('xtext2');
 
         $this->assertEquals(
-            "xtext2",
+            'xtext2',
             $object->getText()
         );
     }
@@ -56,14 +56,14 @@ class PropertyItemsTest extends TestCase
         $object = new BoolPropertyItem('xname');
 
         $this->assertEquals(
-            "xname",
+            'xname',
             $object->getName()
         );
 
         $object->setName('xname2');
 
         $this->assertEquals(
-            "xname2",
+            'xname2',
             $object->getName()
         );
     }
@@ -78,7 +78,7 @@ class PropertyItemsTest extends TestCase
         $object = new BoolPropertyItem();
 
         $this->assertEquals(
-            "bool",
+            'bool',
             $object->getItemType()
         );
     }
@@ -93,7 +93,7 @@ class PropertyItemsTest extends TestCase
         $object = new DocPropertyItem();
 
         $this->assertEquals(
-            "doc",
+            'doc',
             $object->getItemType()
         );
     }
@@ -108,7 +108,7 @@ class PropertyItemsTest extends TestCase
         $object = new HiddenPropertyItem();
 
         $this->assertEquals(
-            "hidden",
+            'hidden',
             $object->getItemType()
         );
     }
@@ -123,7 +123,7 @@ class PropertyItemsTest extends TestCase
         $object = new MessageOnlyPropertyItem();
 
         $this->assertEquals(
-            "messageOnly",
+            'messageOnly',
             $object->getItemType()
         );
     }
@@ -138,7 +138,7 @@ class PropertyItemsTest extends TestCase
         $object = new RadioPropertyItem();
 
         $this->assertEquals(
-            "radio",
+            'radio',
             $object->getItemType()
         );
     }
@@ -153,7 +153,7 @@ class PropertyItemsTest extends TestCase
         $object = new SelectPropertyItem();
 
         $this->assertEquals(
-            "select",
+            'select',
             $object->getItemType()
         );
     }
@@ -168,7 +168,7 @@ class PropertyItemsTest extends TestCase
         $object = new TextPropertyItem();
 
         $this->assertEquals(
-            "text",
+            'text',
             $object->getItemType()
         );
     }
diff --git a/test/classes/Properties/Plugins/PluginPropertyItemTest.php b/test/classes/Properties/Plugins/PluginPropertyItemTest.php
index 75dc74e8ed..98be17ca21 100644
--- a/test/classes/Properties/Plugins/PluginPropertyItemTest.php
+++ b/test/classes/Properties/Plugins/PluginPropertyItemTest.php
@@ -47,7 +47,7 @@ class PluginPropertyItemTest extends TestCase
     public function testGetPropertyType()
     {
         $this->assertEquals(
-            "plugin",
+            'plugin',
             $this->stub->getPropertyType()
         );
     }
diff --git a/test/classes/RelationTest.php b/test/classes/RelationTest.php
index cb3c3a870f..c68618a2b3 100644
--- a/test/classes/RelationTest.php
+++ b/test/classes/RelationTest.php
@@ -40,7 +40,7 @@ class RelationTest extends TestCase
         $GLOBALS['cfg']['Server']['pmadb'] = 'phpmyadmin';
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
         $GLOBALS['cfg']['ZeroConf'] = true;
-        $_SESSION['relation'][$GLOBALS['server']] = "PMA_relation";
+        $_SESSION['relation'][$GLOBALS['server']] = 'PMA_relation';
         $_SESSION['relation'] = [];
 
         $GLOBALS['pmaThemePath'] = $GLOBALS['PMA_Theme']->getPath();
@@ -71,7 +71,7 @@ class RelationTest extends TestCase
         $GLOBALS['dbi'] = $dbi;
         $this->relation->dbi = $GLOBALS['dbi'];
 
-        $sql = "insert into PMA_bookmark A,B values(1, 2)";
+        $sql = 'insert into PMA_bookmark A,B values(1, 2)';
         $this->assertEquals(
             'executeResult1',
             $this->relation->queryAsControlUser($sql)
@@ -120,14 +120,14 @@ class RelationTest extends TestCase
 
         //$cfg['Servers'][$i]['relation']
         $result = "\$cfg['Servers'][\$i]['pmadb']  ... </th><td class=\"right\">"
-            . "<span class=\"success\"><strong>OK</strong></span>";
+            . '<span class="success"><strong>OK</strong></span>';
         $this->assertStringContainsString(
             $result,
             $retval
         );
         // $cfg['Servers'][$i]['relation']
         $result = "\$cfg['Servers'][\$i]['relation']  ... </th><td class=\"right\">"
-            . "<span class=\"caution\"><strong>not OK</strong></span>";
+            . '<span class="caution"><strong>not OK</strong></span>';
         $this->assertStringContainsString(
             $result,
             $retval
@@ -140,8 +140,8 @@ class RelationTest extends TestCase
         );
         // $cfg['Servers'][$i]['table_info']
         $result = "\$cfg['Servers'][\$i]['table_info']  ... </th>"
-            . "<td class=\"right\">"
-            . "<span class=\"caution\"><strong>not OK</strong></span>";
+            . '<td class="right">'
+            . '<span class="caution"><strong>not OK</strong></span>';
         $this->assertStringContainsString(
             $result,
             $retval
@@ -166,7 +166,7 @@ class RelationTest extends TestCase
             $result,
             $retval
         );
-        $result = "<strong>not OK</strong>";
+        $result = '<strong>not OK</strong>';
         $this->assertStringContainsString(
             $result,
             $retval
diff --git a/test/classes/ReplicationGuiTest.php b/test/classes/ReplicationGuiTest.php
index 116842b593..689b49d49a 100644
--- a/test/classes/ReplicationGuiTest.php
+++ b/test/classes/ReplicationGuiTest.php
@@ -45,11 +45,11 @@ class ReplicationGuiTest extends TestCase
     protected function setUp(): void
     {
         //$_POST
-        $_POST['mr_adduser'] = "mr_adduser";
+        $_POST['mr_adduser'] = 'mr_adduser';
 
         //$GLOBALS
         $GLOBALS['cfg']['MaxRows'] = 10;
-        $GLOBALS['cfg']['ServerDefault'] = "server";
+        $GLOBALS['cfg']['ServerDefault'] = 'server';
         $GLOBALS['cfg']['RememberSorting'] = true;
         $GLOBALS['cfg']['SQP'] = [];
         $GLOBALS['cfg']['MaxCharactersInDisplayedSQL'] = 1000;
@@ -59,7 +59,7 @@ class ReplicationGuiTest extends TestCase
         $GLOBALS['cfg']['DBG']['sql'] = false;
         $GLOBALS['cfg']['ShowHint'] = true;
 
-        $GLOBALS['table'] = "table";
+        $GLOBALS['table'] = 'table';
         $GLOBALS['url_params'] = [];
 
         $this->replicationGui = new ReplicationGui(new Replication(), new Template());
@@ -81,7 +81,7 @@ class ReplicationGuiTest extends TestCase
 
         $fetchResult = [
             [
-                "SHOW SLAVE HOSTS",
+                'SHOW SLAVE HOSTS',
                 null,
                 null,
                 DatabaseInterface::CONNECT_USER,
@@ -98,10 +98,10 @@ class ReplicationGuiTest extends TestCase
             ->will($this->returnValueMap($fetchResult));
 
         $fields_info = [
-            "Host" => [
-                "Field" => "host",
-                "Type" => "char(60)",
-                "Null" => "NO",
+            'Host' => [
+                'Field' => 'host',
+                'Type' => 'char(60)',
+                'Null' => 'NO',
             ],
         ];
         $dbi->expects($this->any())->method('getColumns')
@@ -146,16 +146,16 @@ class ReplicationGuiTest extends TestCase
         );
         //$master_variables
         $this->assertStringContainsString(
-            "Binlog_Do_DB",
+            'Binlog_Do_DB',
             $html
         );
         $this->assertStringContainsString(
-            "Binlog_Ignore_DB",
+            'Binlog_Ignore_DB',
             $html
         );
         //$server_master_replication
         $this->assertStringContainsString(
-            "master-bin.000030",
+            'master-bin.000030',
             $html
         );
 
diff --git a/test/classes/SanitizeTest.php b/test/classes/SanitizeTest.php
index 7f12789a57..09a8b4d4c1 100644
--- a/test/classes/SanitizeTest.php
+++ b/test/classes/SanitizeTest.php
@@ -223,7 +223,7 @@ class SanitizeTest extends TestCase
      */
     public function testJsFormat()
     {
-        $this->assertEquals("`foo`", Sanitize::jsFormat('foo'));
+        $this->assertEquals('`foo`', Sanitize::jsFormat('foo'));
     }
 
     /**
diff --git a/test/classes/Server/PrivilegesTest.php b/test/classes/Server/PrivilegesTest.php
index d0f5481caa..93bf453f53 100644
--- a/test/classes/Server/PrivilegesTest.php
+++ b/test/classes/Server/PrivilegesTest.php
@@ -47,12 +47,12 @@ class PrivilegesTest extends TestCase
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
         $GLOBALS['cfgRelation'] = [];
         $GLOBALS['cfgRelation']['menuswork'] = false;
-        $GLOBALS['table'] = "table";
+        $GLOBALS['table'] = 'table';
         $GLOBALS['pmaThemeImage'] = 'image';
         $GLOBALS['server'] = 1;
         $GLOBALS['db'] = 'db';
-        $GLOBALS['hostname'] = "hostname";
-        $GLOBALS['username'] = "username";
+        $GLOBALS['hostname'] = 'hostname';
+        $GLOBALS['username'] = 'username';
 
         $relation = new Relation($GLOBALS['dbi']);
         $this->serverPrivileges = new Privileges(
@@ -120,7 +120,7 @@ class PrivilegesTest extends TestCase
         $GLOBALS['is_grantuser'] = true;
         $GLOBALS['is_createuser'] = true;
         $GLOBALS['is_reload_priv'] = true;
-        $GLOBALS['strPrivDescDeleteHistoricalRows'] = "strPrivDescDeleteHistoricalRows";
+        $GLOBALS['strPrivDescDeleteHistoricalRows'] = 'strPrivDescDeleteHistoricalRows';
     }
 
     /**
@@ -130,10 +130,10 @@ class PrivilegesTest extends TestCase
      */
     public function testGetDataForDBInfo()
     {
-        $_REQUEST['username'] = "PMA_username";
-        $_REQUEST['hostname'] = "PMA_hostname";
-        $_REQUEST['tablename'] = "PMA_tablename";
-        $_REQUEST['dbname'] = "PMA_dbname";
+        $_REQUEST['username'] = 'PMA_username';
+        $_REQUEST['hostname'] = 'PMA_hostname';
+        $_REQUEST['tablename'] = 'PMA_tablename';
+        $_REQUEST['dbname'] = 'PMA_dbname';
         [
             $username,
             $hostname,
@@ -144,23 +144,23 @@ class PrivilegesTest extends TestCase
             $dbname_is_wildcard,
         ] = $this->serverPrivileges->getDataForDBInfo();
         $this->assertEquals(
-            "PMA_username",
+            'PMA_username',
             $username
         );
         $this->assertEquals(
-            "PMA_hostname",
+            'PMA_hostname',
             $hostname
         );
         $this->assertEquals(
-            "PMA_dbname",
+            'PMA_dbname',
             $dbname
         );
         $this->assertEquals(
-            "PMA_tablename",
+            'PMA_tablename',
             $tablename
         );
         $this->assertEquals(
-            "`PMA_dbname`.`PMA_tablename`",
+            '`PMA_dbname`.`PMA_tablename`',
             $db_and_table
         );
         $this->assertEquals(
@@ -169,8 +169,8 @@ class PrivilegesTest extends TestCase
         );
 
         //pre variable have been defined
-        $_POST['pred_tablename'] = "PMA_pred__tablename";
-        $_POST['pred_dbname'] = ["PMA_pred_dbname"];
+        $_POST['pred_tablename'] = 'PMA_pred__tablename';
+        $_POST['pred_dbname'] = ['PMA_pred_dbname'];
         list(
             ,,
             $dbname,
@@ -180,15 +180,15 @@ class PrivilegesTest extends TestCase
             $dbname_is_wildcard,
         ) = $this->serverPrivileges->getDataForDBInfo();
         $this->assertEquals(
-            "PMA_pred_dbname",
+            'PMA_pred_dbname',
             $dbname
         );
         $this->assertEquals(
-            "PMA_pred__tablename",
+            'PMA_pred__tablename',
             $tablename
         );
         $this->assertEquals(
-            "`PMA_pred_dbname`.`PMA_pred__tablename`",
+            '`PMA_pred_dbname`.`PMA_pred__tablename`',
             $db_and_table
         );
         $this->assertEquals(
@@ -236,7 +236,7 @@ class PrivilegesTest extends TestCase
      */
     public function testRangeOfUsers()
     {
-        $ret = $this->serverPrivileges->rangeOfUsers("INIT");
+        $ret = $this->serverPrivileges->rangeOfUsers('INIT');
         $this->assertEquals(
             " WHERE `User` LIKE 'INIT%' OR `User` LIKE 'init%'",
             $ret
@@ -256,14 +256,14 @@ class PrivilegesTest extends TestCase
      */
     public function testGetTableGrantsArray()
     {
-        $GLOBALS['strPrivDescDelete'] = "strPrivDescDelete";
-        $GLOBALS['strPrivDescCreateTbl'] = "strPrivDescCreateTbl";
-        $GLOBALS['strPrivDescDropTbl'] = "strPrivDescDropTbl";
-        $GLOBALS['strPrivDescIndex'] = "strPrivDescIndex";
-        $GLOBALS['strPrivDescAlter'] = "strPrivDescAlter";
-        $GLOBALS['strPrivDescCreateView'] = "strPrivDescCreateView";
-        $GLOBALS['strPrivDescShowView'] = "strPrivDescShowView";
-        $GLOBALS['strPrivDescTrigger'] = "strPrivDescTrigger";
+        $GLOBALS['strPrivDescDelete'] = 'strPrivDescDelete';
+        $GLOBALS['strPrivDescCreateTbl'] = 'strPrivDescCreateTbl';
+        $GLOBALS['strPrivDescDropTbl'] = 'strPrivDescDropTbl';
+        $GLOBALS['strPrivDescIndex'] = 'strPrivDescIndex';
+        $GLOBALS['strPrivDescAlter'] = 'strPrivDescAlter';
+        $GLOBALS['strPrivDescCreateView'] = 'strPrivDescCreateView';
+        $GLOBALS['strPrivDescShowView'] = 'strPrivDescShowView';
+        $GLOBALS['strPrivDescTrigger'] = 'strPrivDescTrigger';
 
         $ret = $this->serverPrivileges->getTableGrantsArray();
         $this->assertEquals(
@@ -317,9 +317,9 @@ class PrivilegesTest extends TestCase
      */
     public function testGetHtmlForUserGroupDialog()
     {
-        $username = "pma_username";
+        $username = 'pma_username';
         $is_menuswork = true;
-        $_GET['edit_user_group_dialog'] = "edit_user_group_dialog";
+        $_GET['edit_user_group_dialog'] = 'edit_user_group_dialog';
 
         /* Assertion 1 */
         $html = $this->serverPrivileges->getHtmlForUserGroupDialog($username, $is_menuswork);
@@ -404,7 +404,7 @@ class PrivilegesTest extends TestCase
      */
     public function testGetHtmlToChooseUserGroup()
     {
-        $username = "pma_username";
+        $username = 'pma_username';
 
         $html = $this->serverPrivileges->getHtmlToChooseUserGroup($username);
         $this->assertStringContainsString(
@@ -432,10 +432,10 @@ class PrivilegesTest extends TestCase
      */
     public function testGetSqlQueryForDisplayPrivTable()
     {
-        $username = "pma_username";
+        $username = 'pma_username';
         $db = '*';
-        $table = "pma_table";
-        $hostname = "pma_hostname";
+        $table = 'pma_table';
+        $hostname = 'pma_hostname';
 
         //$db == '*'
         $ret = $this->serverPrivileges->getSqlQueryForDisplayPrivTable(
@@ -444,7 +444,7 @@ class PrivilegesTest extends TestCase
             $username,
             $hostname
         );
-        $sql = "SELECT * FROM `mysql`.`user`"
+        $sql = 'SELECT * FROM `mysql`.`user`'
             . " WHERE `User` = '" . $GLOBALS['dbi']->escapeString($username) . "'"
             . " AND `Host` = '" . $GLOBALS['dbi']->escapeString($hostname) . "';";
         $this->assertEquals(
@@ -453,35 +453,35 @@ class PrivilegesTest extends TestCase
         );
 
         //$table == '*'
-        $db = "pma_db";
-        $table = "*";
+        $db = 'pma_db';
+        $table = '*';
         $ret = $this->serverPrivileges->getSqlQueryForDisplayPrivTable(
             $db,
             $table,
             $username,
             $hostname
         );
-        $sql = "SELECT * FROM `mysql`.`db`"
+        $sql = 'SELECT * FROM `mysql`.`db`'
             . " WHERE `User` = '" . $GLOBALS['dbi']->escapeString($username) . "'"
             . " AND `Host` = '" . $GLOBALS['dbi']->escapeString($hostname) . "'"
             . " AND '" . Util::unescapeMysqlWildcards($db) . "'"
-            . " LIKE `Db`;";
+            . ' LIKE `Db`;';
         $this->assertEquals(
             $sql,
             $ret
         );
 
         //$table == 'pma_table'
-        $db = "pma_db";
-        $table = "pma_table";
+        $db = 'pma_db';
+        $table = 'pma_table';
         $ret = $this->serverPrivileges->getSqlQueryForDisplayPrivTable(
             $db,
             $table,
             $username,
             $hostname
         );
-        $sql = "SELECT `Table_priv`"
-            . " FROM `mysql`.`tables_priv`"
+        $sql = 'SELECT `Table_priv`'
+            . ' FROM `mysql`.`tables_priv`'
             . " WHERE `User` = '" . $GLOBALS['dbi']->escapeString($username) . "'"
             . " AND `Host` = '" . $GLOBALS['dbi']->escapeString($hostname) . "'"
             . " AND `Db` = '" . Util::unescapeMysqlWildcards($db) . "'"
@@ -493,7 +493,7 @@ class PrivilegesTest extends TestCase
 
         // SQL escaping
         $db = "db' AND";
-        $table = "pma_table";
+        $table = 'pma_table';
         $ret = $this->serverPrivileges->getSqlQueryForDisplayPrivTable(
             $db,
             $table,
@@ -501,7 +501,7 @@ class PrivilegesTest extends TestCase
             $hostname
         );
         $this->assertEquals(
-            "SELECT `Table_priv` FROM `mysql`.`tables_priv` "
+            'SELECT `Table_priv` FROM `mysql`.`tables_priv` '
             . "WHERE `User` = 'pma_username' AND "
             . "`Host` = 'pma_hostname' AND `Db` = 'db' AND' AND "
             . "`Table_name` = 'pma_table';",
@@ -551,8 +551,8 @@ class PrivilegesTest extends TestCase
      */
     public function testGetHtmlForExportUserDefinition()
     {
-        $username = "PMA_username";
-        $hostname = "PMA_hostname";
+        $username = 'PMA_username';
+        $hostname = 'PMA_hostname';
 
         [$title, $export]
             = $this->serverPrivileges->getListForExportUserDefinition($username, $hostname);
@@ -600,7 +600,7 @@ class PrivilegesTest extends TestCase
         $_POST['pred_hostname'] = 'localhost';
         $_POST['pred_password'] = 'keep';
         $_POST['createdb-3'] = true;
-        $_POST['userGroup'] = "username";
+        $_POST['userGroup'] = 'username';
         $_POST['authentication_plugin'] = 'mysql_native_password';
 
         [
@@ -649,7 +649,7 @@ class PrivilegesTest extends TestCase
         $_POST['pred_hostname'] = 'localhost';
         $_POST['pred_password'] = 'keep';
         $_POST['createdb-3'] = true;
-        $_POST['userGroup'] = "username";
+        $_POST['userGroup'] = 'username';
         $_POST['authentication_plugin'] = 'mysql_native_password';
 
         [
@@ -690,7 +690,7 @@ class PrivilegesTest extends TestCase
     {
         $username = 'pma_username';
         $hostname = 'pma_hostname';
-        $err_url = "error.php";
+        $err_url = 'error.php';
         $_POST['pma_pw'] = 'pma_pw';
         $_POST['authentication_plugin'] = 'mysql_native_password';
 
@@ -702,7 +702,7 @@ class PrivilegesTest extends TestCase
 
         $this->assertEquals(
             "The password for 'pma_username'@'pma_hostname' "
-            . "was changed successfully.",
+            . 'was changed successfully.',
             $message->getMessage()
         );
     }
@@ -738,9 +738,9 @@ class PrivilegesTest extends TestCase
             $message->getMessage()
         );
         $this->assertEquals(
-            "REVOKE ALL PRIVILEGES ON  `pma_dbname`.`pma_tablename` "
+            'REVOKE ALL PRIVILEGES ON  `pma_dbname`.`pma_tablename` '
             . "FROM 'pma_username'@'pma_hostname'; "
-            . "REVOKE GRANT OPTION ON  `pma_dbname`.`pma_tablename` "
+            . 'REVOKE GRANT OPTION ON  `pma_dbname`.`pma_tablename` '
             . "FROM 'pma_username'@'pma_hostname';",
             $sql_query
         );
@@ -776,7 +776,7 @@ class PrivilegesTest extends TestCase
             $message->getMessage()
         );
         $this->assertEquals(
-            "REVOKE ALL PRIVILEGES ON  `pma_dbname`.`pma_tablename` "
+            'REVOKE ALL PRIVILEGES ON  `pma_dbname`.`pma_tablename` '
             . "FROM 'pma_username'@'pma_hostname';  ",
             $sql_query
         );
@@ -791,8 +791,8 @@ class PrivilegesTest extends TestCase
     public function testGetHtmlToDisplayPrivilegesTable()
     {
         $dbi_old = $GLOBALS['dbi'];
-        $GLOBALS['hostname'] = "hostname";
-        $GLOBALS['username'] = "username";
+        $GLOBALS['hostname'] = 'hostname';
+        $GLOBALS['username'] = 'username';
 
         //Mock DBI
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
@@ -842,7 +842,7 @@ class PrivilegesTest extends TestCase
         $this->serverPrivileges->dbi = $dbi;
 
         $html = $this->serverPrivileges->getHtmlToDisplayPrivilegesTable();
-        $GLOBALS['username'] = "username";
+        $GLOBALS['username'] = 'username';
 
         //validate 1: fieldset
         $this->assertStringContainsString(
@@ -978,12 +978,12 @@ class PrivilegesTest extends TestCase
             ->will($this->returnValue(50706));
         $this->serverPrivileges->dbi = $GLOBALS['dbi'];
 
-        $username = "PMA_username";
-        $hostname = "PMA_hostname";
-        $password = "pma_password";
+        $username = 'PMA_username';
+        $hostname = 'PMA_hostname';
+        $password = 'pma_password';
         $_POST['pred_password'] = 'keep';
         $_POST['authentication_plugin'] = 'mysql_native_password';
-        $dbname = "PMA_db";
+        $dbname = 'PMA_db';
 
         [
             $create_user_real,
@@ -1055,7 +1055,7 @@ class PrivilegesTest extends TestCase
 
         //validate 6: $message
         $this->assertEquals(
-            "You have added a new user.",
+            'You have added a new user.',
             $message->getMessage()
         );
     }
@@ -1217,9 +1217,9 @@ class PrivilegesTest extends TestCase
         $_POST['max_user_connections'] = 40;
 
         $sql_query = $this->serverPrivileges->getWithClauseForAddUserAndUpdatePrivs();
-        $expect = "WITH GRANT OPTION MAX_QUERIES_PER_HOUR 10 "
-            . "MAX_CONNECTIONS_PER_HOUR 20"
-            . " MAX_UPDATES_PER_HOUR 30 MAX_USER_CONNECTIONS 40";
+        $expect = 'WITH GRANT OPTION MAX_QUERIES_PER_HOUR 10 '
+            . 'MAX_CONNECTIONS_PER_HOUR 20'
+            . ' MAX_UPDATES_PER_HOUR 30 MAX_USER_CONNECTIONS 40';
         $this->assertStringContainsString(
             $expect,
             $sql_query
@@ -1257,7 +1257,7 @@ class PrivilegesTest extends TestCase
         $GLOBALS['dbi'] = $dbi;
         $this->serverPrivileges->dbi = $dbi;
 
-        $dbname = "pma_dbname";
+        $dbname = 'pma_dbname';
 
         $html = $this->serverPrivileges->getHtmlForAddUser($dbname);
 
@@ -1311,10 +1311,10 @@ class PrivilegesTest extends TestCase
      */
     public function testGetUserLink()
     {
-        $username = "pma_username";
-        $hostname = "pma_hostname";
-        $dbname = "pma_dbname";
-        $tablename = "pma_tablename";
+        $username = 'pma_username';
+        $hostname = 'pma_hostname';
+        $dbname = 'pma_dbname';
+        $tablename = 'pma_tablename';
 
         $html = $this->serverPrivileges->getUserLink(
             'edit',
@@ -1395,17 +1395,17 @@ class PrivilegesTest extends TestCase
      */
     public function testGetExtraDataForAjaxBehavior()
     {
-        $password = "pma_password";
-        $sql_query = "pma_sql_query";
-        $username = "pma_username";
-        $hostname = "pma_hostname";
-        $GLOBALS['dbname'] = "pma_dbname";
-        $_POST['adduser_submit'] = "adduser_submit";
-        $_POST['username'] = "username";
-        $_POST['change_copy'] = "change_copy";
-        $_GET['validate_username'] = "validate_username";
-        $_GET['username'] = "username";
-        $_POST['update_privs'] = "update_privs";
+        $password = 'pma_password';
+        $sql_query = 'pma_sql_query';
+        $username = 'pma_username';
+        $hostname = 'pma_hostname';
+        $GLOBALS['dbname'] = 'pma_dbname';
+        $_POST['adduser_submit'] = 'adduser_submit';
+        $_POST['username'] = 'username';
+        $_POST['change_copy'] = 'change_copy';
+        $_GET['validate_username'] = 'validate_username';
+        $_GET['username'] = 'username';
+        $_POST['update_privs'] = 'update_privs';
 
         $extra_data = $this->serverPrivileges->getExtraDataForAjaxBehavior(
             $password,
@@ -1468,14 +1468,14 @@ class PrivilegesTest extends TestCase
      */
     public function testGetUserGroupForUser()
     {
-        $username = "pma_username";
+        $username = 'pma_username';
         $GLOBALS['cfgRelation']['menuswork'] = true;
 
         $dbi_old = $GLOBALS['dbi'];
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
             ->disableOriginalConstructor()
             ->getMock();
-        $expected_userGroup = "pma_usergroup";
+        $expected_userGroup = 'pma_usergroup';
 
         $dbi->expects($this->any())->method('fetchValue')
             ->will($this->returnValue($expected_userGroup));
@@ -1506,8 +1506,8 @@ class PrivilegesTest extends TestCase
     {
         $result = [];
         $db_rights = [];
-        $pmaThemeImage = "pmaThemeImage";
-        $text_dir = "text_dir";
+        $pmaThemeImage = 'pmaThemeImage';
+        $text_dir = 'text_dir';
         $GLOBALS['cfgRelation']['menuswork'] = true;
 
         $html = $this->serverPrivileges->getUsersOverview(
@@ -1606,9 +1606,9 @@ class PrivilegesTest extends TestCase
      */
     public function testGetDataForDeleteUsers()
     {
-        $_POST['change_copy'] = "change_copy";
-        $_POST['old_hostname'] = "old_hostname";
-        $_POST['old_username'] = "old_username";
+        $_POST['change_copy'] = 'change_copy';
+        $_POST['old_hostname'] = 'old_hostname';
+        $_POST['old_username'] = 'old_username';
         $_SESSION['relation'][1] = [
             'PMA_VERSION' => PMA_VERSION,
             'bookmarkwork' => false,
@@ -1668,12 +1668,12 @@ class PrivilegesTest extends TestCase
     public function testGetHtmlHeaderForUserProperties()
     {
         $dbname_is_wildcard = true;
-        $url_dbname = "url_dbname";
-        $dbname = "dbname";
-        $username = "username";
-        $hostname = "hostname";
-        $tablename = "tablename";
-        $_REQUEST['tablename'] = "tablename";
+        $url_dbname = 'url_dbname';
+        $dbname = 'dbname';
+        $username = 'username';
+        $hostname = 'hostname';
+        $tablename = 'tablename';
+        $_REQUEST['tablename'] = 'tablename';
 
         $html = $this->serverPrivileges->getHtmlForUserProperties(
             $dbname_is_wildcard,
@@ -2173,7 +2173,7 @@ class PrivilegesTest extends TestCase
         $actual = $this->serverPrivileges->deleteUser($queries);
         $this->assertArrayHasKey(0, $actual);
         $this->assertArrayHasKey(1, $actual);
-        $this->assertEquals("bar", $actual[0]);
+        $this->assertEquals('bar', $actual[0]);
         $this->assertEquals(
             'Some error occurred!' . "\n",
             $actual[1]->getMessage()
diff --git a/test/classes/Server/SelectTest.php b/test/classes/Server/SelectTest.php
index af68ec8e33..2f0fff106f 100644
--- a/test/classes/Server/SelectTest.php
+++ b/test/classes/Server/SelectTest.php
@@ -30,13 +30,13 @@ class SelectTest extends TestCase
     protected function setUp(): void
     {
         //$_REQUEST
-        $_REQUEST['log'] = "index1";
+        $_REQUEST['log'] = 'index1';
         $_REQUEST['pos'] = 3;
 
         //$GLOBALS
         $GLOBALS['cfg']['MaxRows'] = 10;
         $GLOBALS['server'] = 1;
-        $GLOBALS['cfg']['ServerDefault'] = "server";
+        $GLOBALS['cfg']['ServerDefault'] = 'server';
         $GLOBALS['cfg']['RememberSorting'] = true;
         $GLOBALS['cfg']['SQP'] = [];
         $GLOBALS['cfg']['MaxCharactersInDisplayedSQL'] = 1000;
@@ -44,7 +44,7 @@ class SelectTest extends TestCase
         $GLOBALS['cfg']['TableNavigationLinksMode'] = 'icons';
         $GLOBALS['cfg']['LimitChars'] = 100;
 
-        $GLOBALS['table'] = "table";
+        $GLOBALS['table'] = 'table';
 
         //$_SESSION
     }
@@ -59,7 +59,7 @@ class SelectTest extends TestCase
         $not_only_options = false;
         $omit_fieldset = false;
 
-        $GLOBALS['cfg']['DefaultTabServer'] = "welcome";
+        $GLOBALS['cfg']['DefaultTabServer'] = 'welcome';
 
         $GLOBALS['cfg']['Servers'] = [
             '0' => [
diff --git a/test/classes/Server/UserGroupsTest.php b/test/classes/Server/UserGroupsTest.php
index 4e07b5b04d..311c8d3ef1 100644
--- a/test/classes/Server/UserGroupsTest.php
+++ b/test/classes/Server/UserGroupsTest.php
@@ -47,8 +47,8 @@ class UserGroupsTest extends TestCase
      */
     public function testGetHtmlForUserGroupsTableWithNoUserGroups()
     {
-        $expectedQuery = "SELECT * FROM `pmadb`.`usergroups`"
-            . " ORDER BY `usergroup` ASC";
+        $expectedQuery = 'SELECT * FROM `pmadb`.`usergroups`'
+            . ' ORDER BY `usergroup` ASC';
 
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
             ->disableOriginalConstructor()
@@ -84,8 +84,8 @@ class UserGroupsTest extends TestCase
      */
     public function testGetHtmlForUserGroupsTableWithUserGroups()
     {
-        $expectedQuery = "SELECT * FROM `pmadb`.`usergroups`"
-            . " ORDER BY `usergroup` ASC";
+        $expectedQuery = 'SELECT * FROM `pmadb`.`usergroups`'
+            . ' ORDER BY `usergroup` ASC';
 
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
             ->disableOriginalConstructor()
@@ -168,9 +168,9 @@ class UserGroupsTest extends TestCase
      */
     public function testDeleteUserGroup()
     {
-        $userDelQuery = "DELETE FROM `pmadb`.`users`"
+        $userDelQuery = 'DELETE FROM `pmadb`.`users`'
             . " WHERE `usergroup`='ug'";
-        $userGrpDelQuery = "DELETE FROM `pmadb`.`usergroups`"
+        $userGrpDelQuery = 'DELETE FROM `pmadb`.`usergroups`'
             . " WHERE `usergroup`='ug'";
 
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
@@ -209,7 +209,7 @@ class UserGroupsTest extends TestCase
             $html
         );
 
-        $expectedQuery = "SELECT * FROM `pmadb`.`usergroups`"
+        $expectedQuery = 'SELECT * FROM `pmadb`.`usergroups`'
             . " WHERE `usergroup`='ug'";
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
             ->disableOriginalConstructor()
diff --git a/test/classes/Setup/ConfigGeneratorTest.php b/test/classes/Setup/ConfigGeneratorTest.php
index 41753b34d3..ed49806af5 100644
--- a/test/classes/Setup/ConfigGeneratorTest.php
+++ b/test/classes/Setup/ConfigGeneratorTest.php
@@ -48,7 +48,7 @@ class ConfigGeneratorTest extends PmaTestCase
             ],
         ];
 
-        $cf->setPersistKeys(["1/", 2]);
+        $cf->setPersistKeys(['1/', 2]);
 
         $result = ConfigGenerator::getConfigFile($cf);
 
@@ -56,7 +56,7 @@ class ConfigGeneratorTest extends PmaTestCase
             "<?php\n" .
             "/*\n" .
             " * Generated configuration file\n" .
-            " * Generated by: phpMyAdmin " .
+            ' * Generated by: phpMyAdmin ' .
             $GLOBALS['PMA_Config']->get('PMA_VERSION') . " setup script\n",
             $result
         );
diff --git a/test/classes/SqlQueryFormTest.php b/test/classes/SqlQueryFormTest.php
index 8e5e79d094..5af6630af7 100644
--- a/test/classes/SqlQueryFormTest.php
+++ b/test/classes/SqlQueryFormTest.php
@@ -42,19 +42,19 @@ class SqlQueryFormTest extends TestCase
         //$GLOBALS
         $GLOBALS['max_upload_size'] = 100;
         $GLOBALS['PMA_PHP_SELF'] = Core::getenv('PHP_SELF');
-        $GLOBALS['db'] = "PMA_db";
-        $GLOBALS['table'] = "PMA_table";
-        $GLOBALS['text_dir'] = "text_dir";
+        $GLOBALS['db'] = 'PMA_db';
+        $GLOBALS['table'] = 'PMA_table';
+        $GLOBALS['text_dir'] = 'text_dir';
         $GLOBALS['server'] = 0;
 
         $GLOBALS['cfg']['GZipDump'] = false;
         $GLOBALS['cfg']['BZipDump'] = false;
         $GLOBALS['cfg']['ZipDump'] = false;
-        $GLOBALS['cfg']['ServerDefault'] = "default";
+        $GLOBALS['cfg']['ServerDefault'] = 'default';
         $GLOBALS['cfg']['TextareaAutoSelect'] = true;
         $GLOBALS['cfg']['TextareaRows'] = 100;
         $GLOBALS['cfg']['TextareaCols'] = 11;
-        $GLOBALS['cfg']['DefaultTabDatabase'] = "structure";
+        $GLOBALS['cfg']['DefaultTabDatabase'] = 'structure';
         $GLOBALS['cfg']['RetainQueryBox'] = true;
         $GLOBALS['cfg']['ActionLinksMode'] = 'both';
         $GLOBALS['cfg']['DefaultTabTable'] = 'browse';
@@ -64,18 +64,18 @@ class SqlQueryFormTest extends TestCase
         //_SESSION
         $_SESSION['relation'][0] = [
             'PMA_VERSION' => PMA_VERSION,
-            'table_coords' => "table_name",
+            'table_coords' => 'table_name',
             'displaywork' => 'displaywork',
-            'db' => "information_schema",
+            'db' => 'information_schema',
             'table_info' => 'table_info',
             'relwork' => 'relwork',
             'relation' => 'relation',
             'bookmarkwork' => false,
         ];
         //$GLOBALS
-        $GLOBALS['cfg']['Server']['user'] = "user";
-        $GLOBALS['cfg']['Server']['pmadb'] = "pmadb";
-        $GLOBALS['cfg']['Server']['bookmarktable'] = "bookmarktable";
+        $GLOBALS['cfg']['Server']['user'] = 'user';
+        $GLOBALS['cfg']['Server']['pmadb'] = 'pmadb';
+        $GLOBALS['cfg']['Server']['bookmarktable'] = 'bookmarktable';
 
         //$_SESSION
 
@@ -85,8 +85,8 @@ class SqlQueryFormTest extends TestCase
             ->getMock();
 
         $fetchResult = [
-            "index1" => "table1",
-            "index2" => "table2",
+            'index1' => 'table1',
+            'index2' => 'table2',
         ];
         $dbi->expects($this->any())
             ->method('fetchResult')
@@ -94,8 +94,8 @@ class SqlQueryFormTest extends TestCase
 
         $getColumns = [
             [
-                "Field" => "field1",
-                "Comment" => "Comment1",
+                'Field' => 'field1',
+                'Comment' => 'Comment1',
             ],
         ];
         $dbi->expects($this->any())
@@ -113,7 +113,7 @@ class SqlQueryFormTest extends TestCase
     public function testPMAGetHtmlForSqlQueryFormInsert()
     {
         //Call the test function
-        $query = "select * from PMA";
+        $query = 'select * from PMA';
         $html = $this->sqlQueryForm->getHtml($query);
 
         //validate 1: query
@@ -178,7 +178,7 @@ class SqlQueryFormTest extends TestCase
         //Call the test function
         $GLOBALS['is_upload'] = true;
         $GLOBALS['lang'] = 'ja';
-        $query = "select * from PMA";
+        $query = 'select * from PMA';
         $html = $this->sqlQueryForm->getHtml($query);
 
         //validate 1: query
diff --git a/test/classes/Stubs/DbiDummy.php b/test/classes/Stubs/DbiDummy.php
index 59f5bddbe8..f0946b4bab 100644
--- a/test/classes/Stubs/DbiDummy.php
+++ b/test/classes/Stubs/DbiDummy.php
@@ -113,7 +113,7 @@ class DbiDummy implements DbiExtension
 
             return $i + self::OFFSET_GLOBAL;
         }
-        echo "Not supported query: $query\n";
+        echo 'Not supported query: ' . $query . "\n";
 
         return false;
     }
@@ -509,20 +509,20 @@ class DbiDummy implements DbiExtension
                 'result' => [['1']],
             ],
             [
-                'query'  => "SELECT 1 FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES`"
+                'query'  => 'SELECT 1 FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES`'
                     . " WHERE `PRIVILEGE_TYPE` = 'CREATE USER'"
                     . " AND '''pma_test''@''localhost''' LIKE `GRANTEE` LIMIT 1",
                 'result' => [['1']],
             ],
             [
-                'query'  => "SELECT 1 FROM (SELECT `GRANTEE`, `IS_GRANTABLE`"
-                    . " FROM `INFORMATION_SCHEMA`.`COLUMN_PRIVILEGES`"
-                    . " UNION SELECT `GRANTEE`, `IS_GRANTABLE`"
-                    . " FROM `INFORMATION_SCHEMA`.`TABLE_PRIVILEGES`"
-                    . " UNION SELECT `GRANTEE`, `IS_GRANTABLE`"
-                    . " FROM `INFORMATION_SCHEMA`.`SCHEMA_PRIVILEGES`"
-                    . " UNION SELECT `GRANTEE`, `IS_GRANTABLE`"
-                    . " FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES`) t"
+                'query'  => 'SELECT 1 FROM (SELECT `GRANTEE`, `IS_GRANTABLE`'
+                    . ' FROM `INFORMATION_SCHEMA`.`COLUMN_PRIVILEGES`'
+                    . ' UNION SELECT `GRANTEE`, `IS_GRANTABLE`'
+                    . ' FROM `INFORMATION_SCHEMA`.`TABLE_PRIVILEGES`'
+                    . ' UNION SELECT `GRANTEE`, `IS_GRANTABLE`'
+                    . ' FROM `INFORMATION_SCHEMA`.`SCHEMA_PRIVILEGES`'
+                    . ' UNION SELECT `GRANTEE`, `IS_GRANTABLE`'
+                    . ' FROM `INFORMATION_SCHEMA`.`USER_PRIVILEGES`) t'
                     . " WHERE `IS_GRANTABLE` = 'YES'"
                     . " AND '''pma_test''@''localhost''' LIKE `GRANTEE` LIMIT 1",
                 'result' => [['1']],
@@ -1187,13 +1187,13 @@ class DbiDummy implements DbiExtension
                 'result' => [],
             ],
             [
-                'query'  => "SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`."
+                'query'  => 'SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`.'
                     . "`SCHEMA_PRIVILEGES` WHERE GRANTEE='''pma_test''@''localhost'''"
                     . " AND PRIVILEGE_TYPE='EVENT' AND TABLE_SCHEMA='pma'",
                 'result' => [],
             ],
             [
-                'query'  => "SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`."
+                'query'  => 'SELECT `PRIVILEGE_TYPE` FROM `INFORMATION_SCHEMA`.'
                     . "`SCHEMA_PRIVILEGES` WHERE GRANTEE='''pma_test''@''localhost'''"
                     . " AND PRIVILEGE_TYPE='TRIGGER' AND TABLE_SCHEMA='pma'",
                 'result' => [],
@@ -1214,28 +1214,28 @@ class DbiDummy implements DbiExtension
                 ],
             ],
             [
-                'query'  => "SHOW TABLES FROM `phpmyadmin`",
+                'query'  => 'SHOW TABLES FROM `phpmyadmin`',
                 'result' => [],
             ],
             [
-                'query'   => "SELECT tracking_active FROM `pmadb`.`tracking`" .
+                'query'   => 'SELECT tracking_active FROM `pmadb`.`tracking`' .
                     " WHERE db_name = 'pma_test_db'" .
                     " AND table_name = 'pma_test_table'" .
-                    " ORDER BY version DESC LIMIT 1",
+                    ' ORDER BY version DESC LIMIT 1',
                 'columns' => ['tracking_active'],
                 'result'  => [
                     [1],
                 ],
             ],
             [
-                'query'  => "SELECT tracking_active FROM `pmadb`.`tracking`" .
+                'query'  => 'SELECT tracking_active FROM `pmadb`.`tracking`' .
                     " WHERE db_name = 'pma_test_db'" .
                     " AND table_name = 'pma_test_table2'" .
-                    " ORDER BY version DESC LIMIT 1",
+                    ' ORDER BY version DESC LIMIT 1',
                 'result' => [],
             ],
             [
-                'query'  => "SHOW SLAVE STATUS",
+                'query'  => 'SHOW SLAVE STATUS',
                 'result' => [
                     [
                         'Slave_IO_State'              => 'running',
@@ -1275,43 +1275,43 @@ class DbiDummy implements DbiExtension
                 ],
             ],
             [
-                'query'  => "SHOW MASTER STATUS",
+                'query'  => 'SHOW MASTER STATUS',
                 'result' => [
                     [
-                        "File"             => "master-bin.000030",
-                        "Position"         => "107",
-                        "Binlog_Do_DB"     => "Binlog_Do_DB",
-                        "Binlog_Ignore_DB" => "Binlog_Ignore_DB",
+                        'File'             => 'master-bin.000030',
+                        'Position'         => '107',
+                        'Binlog_Do_DB'     => 'Binlog_Do_DB',
+                        'Binlog_Ignore_DB' => 'Binlog_Ignore_DB',
                     ],
                 ],
             ],
             [
-                'query'  => "SHOW GRANTS",
+                'query'  => 'SHOW GRANTS',
                 'result' => [],
             ],
             [
-                'query'  => "SELECT `SCHEMA_NAME` FROM `INFORMATION_SCHEMA`.`SCHEMATA`, "
-                    . "(SELECT DB_first_level FROM ( SELECT DISTINCT "
+                'query'  => 'SELECT `SCHEMA_NAME` FROM `INFORMATION_SCHEMA`.`SCHEMATA`, '
+                    . '(SELECT DB_first_level FROM ( SELECT DISTINCT '
                     . "SUBSTRING_INDEX(SCHEMA_NAME, '_', 1) DB_first_level "
-                    . "FROM INFORMATION_SCHEMA.SCHEMATA WHERE TRUE ) t ORDER BY "
-                    . "DB_first_level ASC LIMIT 0, 100) t2 WHERE TRUE AND 1 = LOCATE("
+                    . 'FROM INFORMATION_SCHEMA.SCHEMATA WHERE TRUE ) t ORDER BY '
+                    . 'DB_first_level ASC LIMIT 0, 100) t2 WHERE TRUE AND 1 = LOCATE('
                     . "CONCAT(DB_first_level, '_'), CONCAT(SCHEMA_NAME, '_')) "
-                    . "ORDER BY SCHEMA_NAME ASC",
+                    . 'ORDER BY SCHEMA_NAME ASC',
                 'result' => [
-                    "test",
+                    'test',
                 ],
             ],
             [
-                'query'  => "SELECT COUNT(*) FROM ( SELECT DISTINCT SUBSTRING_INDEX("
+                'query'  => 'SELECT COUNT(*) FROM ( SELECT DISTINCT SUBSTRING_INDEX('
                     . "SCHEMA_NAME, '_', 1) DB_first_level "
-                    . "FROM INFORMATION_SCHEMA.SCHEMATA WHERE TRUE ) t",
+                    . 'FROM INFORMATION_SCHEMA.SCHEMATA WHERE TRUE ) t',
                 'result' => [
                     [1],
                 ],
             ],
             [
-                'query'  => "SELECT `PARTITION_METHOD` "
-                    . "FROM `information_schema`.`PARTITIONS` "
+                'query'  => 'SELECT `PARTITION_METHOD` '
+                    . 'FROM `information_schema`.`PARTITIONS` '
                     . "WHERE `TABLE_SCHEMA` = 'db' AND `TABLE_NAME` = 'table' LIMIT 1",
                 'result' => [],
             ],
@@ -1351,50 +1351,50 @@ class DbiDummy implements DbiExtension
                 'query'  => "SHOW FULL TABLES FROM `default` WHERE `Table_type`IN('BASE TABLE', 'SYSTEM VERSIONED')",
                 'result' => [
                     [
-                        "test1",
-                        "BASE TABLE",
+                        'test1',
+                        'BASE TABLE',
                     ],
                     [
-                        "test2",
-                        "BASE TABLE",
+                        'test2',
+                        'BASE TABLE',
                     ],
                 ],
             ],
             [
-                'query'  => "SHOW FULL TABLES FROM `default` "
+                'query'  => 'SHOW FULL TABLES FROM `default` '
                     . "WHERE `Table_type`NOT IN('BASE TABLE', 'SYSTEM VERSIONED')",
                 'result' => [],
             ],
             [
                 'query'  => "SHOW FUNCTION STATUS WHERE `Db`='default'",
-                'result' => [["Name" => "testFunction"]],
+                'result' => [['Name' => 'testFunction']],
             ],
             [
                 'query'  => "SHOW PROCEDURE STATUS WHERE `Db`='default'",
                 'result' => [],
             ],
             [
-                'query'  => "SHOW EVENTS FROM `default`",
+                'query'  => 'SHOW EVENTS FROM `default`',
                 'result' => [],
             ],
             [
-                'query'  => "FLUSH PRIVILEGES",
+                'query'  => 'FLUSH PRIVILEGES',
                 'result' => [],
             ],
             [
-                'query'  => "SELECT * FROM `mysql`.`db` LIMIT 1",
+                'query'  => 'SELECT * FROM `mysql`.`db` LIMIT 1',
                 'result' => [],
             ],
             [
-                'query'  => "SELECT * FROM `mysql`.`columns_priv` LIMIT 1",
+                'query'  => 'SELECT * FROM `mysql`.`columns_priv` LIMIT 1',
                 'result' => [],
             ],
             [
-                'query'  => "SELECT * FROM `mysql`.`tables_priv` LIMIT 1",
+                'query'  => 'SELECT * FROM `mysql`.`tables_priv` LIMIT 1',
                 'result' => [],
             ],
             [
-                'query'  => "SELECT * FROM `mysql`.`procs_priv` LIMIT 1",
+                'query'  => 'SELECT * FROM `mysql`.`procs_priv` LIMIT 1',
                 'result' => [],
             ],
             [
@@ -1430,26 +1430,26 @@ class DbiDummy implements DbiExtension
                 ],
             ],
             [
-                'query'  => "SELECT TABLE_NAME FROM information_schema.VIEWS WHERE "
+                'query'  => 'SELECT TABLE_NAME FROM information_schema.VIEWS WHERE '
                     . "TABLE_SCHEMA = 'db' AND TABLE_NAME = 'table'",
                 'result' => [],
             ],
             [
-                'query'  => "SELECT *, `TABLE_SCHEMA` AS `Db`, "
-                    . "`TABLE_NAME` AS `Name`, `TABLE_TYPE` AS `TABLE_TYPE`, "
-                    . "`ENGINE` AS `Engine`, `ENGINE` AS `Type`, "
-                    . "`VERSION` AS `Version`, `ROW_FORMAT` AS `Row_format`, "
-                    . "`TABLE_ROWS` AS `Rows`, `AVG_ROW_LENGTH` AS `Avg_row_length`, "
-                    . "`DATA_LENGTH` AS `Data_length`, "
-                    . "`MAX_DATA_LENGTH` AS `Max_data_length`, "
-                    . "`INDEX_LENGTH` AS `Index_length`, `DATA_FREE` AS `Data_free`, "
-                    . "`AUTO_INCREMENT` AS `Auto_increment`, "
-                    . "`CREATE_TIME` AS `Create_time`, "
-                    . "`UPDATE_TIME` AS `Update_time`, `CHECK_TIME` AS `Check_time`, "
-                    . "`TABLE_COLLATION` AS `Collation`, `CHECKSUM` AS `Checksum`, "
-                    . "`CREATE_OPTIONS` AS `Create_options`, "
-                    . "`TABLE_COMMENT` AS `Comment` "
-                    . "FROM `information_schema`.`TABLES` t "
+                'query'  => 'SELECT *, `TABLE_SCHEMA` AS `Db`, '
+                    . '`TABLE_NAME` AS `Name`, `TABLE_TYPE` AS `TABLE_TYPE`, '
+                    . '`ENGINE` AS `Engine`, `ENGINE` AS `Type`, '
+                    . '`VERSION` AS `Version`, `ROW_FORMAT` AS `Row_format`, '
+                    . '`TABLE_ROWS` AS `Rows`, `AVG_ROW_LENGTH` AS `Avg_row_length`, '
+                    . '`DATA_LENGTH` AS `Data_length`, '
+                    . '`MAX_DATA_LENGTH` AS `Max_data_length`, '
+                    . '`INDEX_LENGTH` AS `Index_length`, `DATA_FREE` AS `Data_free`, '
+                    . '`AUTO_INCREMENT` AS `Auto_increment`, '
+                    . '`CREATE_TIME` AS `Create_time`, '
+                    . '`UPDATE_TIME` AS `Update_time`, `CHECK_TIME` AS `Check_time`, '
+                    . '`TABLE_COLLATION` AS `Collation`, `CHECKSUM` AS `Checksum`, '
+                    . '`CREATE_OPTIONS` AS `Create_options`, '
+                    . '`TABLE_COMMENT` AS `Comment` '
+                    . 'FROM `information_schema`.`TABLES` t '
                     . "WHERE `TABLE_SCHEMA` IN ('db') "
                     . "AND t.`TABLE_NAME` = 'table' ORDER BY Name ASC",
                 'result' => [],
@@ -1459,16 +1459,16 @@ class DbiDummy implements DbiExtension
                 'result' => [],
             ],
             [
-                'query'  => "SELECT *, `TABLE_SCHEMA` AS `Db`, `TABLE_NAME` AS `Name`,"
-                . " `TABLE_TYPE` AS `TABLE_TYPE`, `ENGINE` AS `Engine`,"
-                . " `ENGINE` AS `Type`, `VERSION` AS `Version`, `ROW_FORMAT` AS `Row_format`,"
-                . " `TABLE_ROWS` AS `Rows`, `AVG_ROW_LENGTH` AS `Avg_row_length`,"
-                . " `DATA_LENGTH` AS `Data_length`, `MAX_DATA_LENGTH` AS `Max_data_length`,"
-                . " `INDEX_LENGTH` AS `Index_length`, `DATA_FREE` AS `Data_free`,"
-                . " `AUTO_INCREMENT` AS `Auto_increment`, `CREATE_TIME` AS `Create_time`,"
-                . " `UPDATE_TIME` AS `Update_time`, `CHECK_TIME` AS `Check_time`,"
-                . " `TABLE_COLLATION` AS `Collation`, `CHECKSUM` AS `Checksum`,"
-                . " `CREATE_OPTIONS` AS `Create_options`, `TABLE_COMMENT` AS `Comment`"
+                'query'  => 'SELECT *, `TABLE_SCHEMA` AS `Db`, `TABLE_NAME` AS `Name`,'
+                . ' `TABLE_TYPE` AS `TABLE_TYPE`, `ENGINE` AS `Engine`,'
+                . ' `ENGINE` AS `Type`, `VERSION` AS `Version`, `ROW_FORMAT` AS `Row_format`,'
+                . ' `TABLE_ROWS` AS `Rows`, `AVG_ROW_LENGTH` AS `Avg_row_length`,'
+                . ' `DATA_LENGTH` AS `Data_length`, `MAX_DATA_LENGTH` AS `Max_data_length`,'
+                . ' `INDEX_LENGTH` AS `Index_length`, `DATA_FREE` AS `Data_free`,'
+                . ' `AUTO_INCREMENT` AS `Auto_increment`, `CREATE_TIME` AS `Create_time`,'
+                . ' `UPDATE_TIME` AS `Update_time`, `CHECK_TIME` AS `Check_time`,'
+                . ' `TABLE_COLLATION` AS `Collation`, `CHECKSUM` AS `Checksum`,'
+                . ' `CREATE_OPTIONS` AS `Create_options`, `TABLE_COMMENT` AS `Comment`'
                 . " FROM `information_schema`.`TABLES` t WHERE `TABLE_SCHEMA` IN ('table1')"
                 . " AND t.`TABLE_NAME` = 'pma_test' ORDER BY Name ASC",
                 'columns' => [
@@ -1617,7 +1617,7 @@ class DbiDummy implements DbiExtension
                 ],
             ],
             [
-                'query' => "SELECT *, CAST(BIN_NAME AS CHAR CHARACTER SET utf8) AS SCHEMA_NAME FROM (SELECT BINARY s.SCHEMA_NAME AS BIN_NAME, s.DEFAULT_COLLATION_NAME FROM `information_schema`.SCHEMATA s GROUP BY BINARY s.SCHEMA_NAME, s.DEFAULT_COLLATION_NAME ORDER BY BINARY `SCHEMA_NAME` ASC) a",
+                'query' => 'SELECT *, CAST(BIN_NAME AS CHAR CHARACTER SET utf8) AS SCHEMA_NAME FROM (SELECT BINARY s.SCHEMA_NAME AS BIN_NAME, s.DEFAULT_COLLATION_NAME FROM `information_schema`.SCHEMATA s GROUP BY BINARY s.SCHEMA_NAME, s.DEFAULT_COLLATION_NAME ORDER BY BINARY `SCHEMA_NAME` ASC) a',
                 'columns' => [
                     'BIN_NAME',
                     'DEFAULT_COLLATION_NAME',
@@ -1676,58 +1676,58 @@ class DbiDummy implements DbiExtension
                 ],
             ],
             [
-                'query'  => "SELECT @@have_partitioning;",
+                'query'  => 'SELECT @@have_partitioning;',
                 'result' => [],
             ],
             [
-                'query'  => "SELECT @@lower_case_table_names",
+                'query'  => 'SELECT @@lower_case_table_names',
                 'result' => [],
             ],
             [
-                'query'  => "SELECT `PLUGIN_NAME`, `PLUGIN_DESCRIPTION` "
-                    . "FROM `information_schema`.`PLUGINS` "
+                'query'  => 'SELECT `PLUGIN_NAME`, `PLUGIN_DESCRIPTION` '
+                    . 'FROM `information_schema`.`PLUGINS` '
                     . "WHERE `PLUGIN_TYPE` = 'AUTHENTICATION';",
                 'result' => [],
             ],
             [
-                'query'  => "SHOW TABLES FROM `db`;",
+                'query'  => 'SHOW TABLES FROM `db`;',
                 'result' => [],
             ],
             [
-                'query'  => "SELECT `PRIVILEGE_TYPE` FROM "
-                    . "`INFORMATION_SCHEMA`.`SCHEMA_PRIVILEGES` "
+                'query'  => 'SELECT `PRIVILEGE_TYPE` FROM '
+                    . '`INFORMATION_SCHEMA`.`SCHEMA_PRIVILEGES` '
                     . "WHERE GRANTEE='''pma_test''@''localhost''' "
                     . "AND PRIVILEGE_TYPE='EVENT' AND 'db' LIKE `TABLE_SCHEMA`",
                 'result' => [],
             ],
             [
-                'query'  => "SELECT `PRIVILEGE_TYPE` FROM "
-                    . "`INFORMATION_SCHEMA`.`SCHEMA_PRIVILEGES` "
+                'query'  => 'SELECT `PRIVILEGE_TYPE` FROM '
+                    . '`INFORMATION_SCHEMA`.`SCHEMA_PRIVILEGES` '
                     . "WHERE GRANTEE='''pma_test''@''localhost''' "
                     . "AND PRIVILEGE_TYPE='TRIGGER' AND 'db' LIKE `TABLE_SCHEMA`",
                 'result' => [],
             ],
             [
-                'query'  => "SELECT (COUNT(DB_first_level) DIV 100) * 100 from "
+                'query'  => 'SELECT (COUNT(DB_first_level) DIV 100) * 100 from '
                     . "( SELECT distinct SUBSTRING_INDEX(SCHEMA_NAME, '_', 1) "
-                    . "DB_first_level FROM INFORMATION_SCHEMA.SCHEMATA "
+                    . 'DB_first_level FROM INFORMATION_SCHEMA.SCHEMATA '
                     . "WHERE `SCHEMA_NAME` < 'db' ) t",
                 'result' => [],
             ],
             [
-                'query'  => "SELECT (COUNT(DB_first_level) DIV 100) * 100 from "
+                'query'  => 'SELECT (COUNT(DB_first_level) DIV 100) * 100 from '
                     . "( SELECT distinct SUBSTRING_INDEX(SCHEMA_NAME, '_', 1) "
-                    . "DB_first_level FROM INFORMATION_SCHEMA.SCHEMATA "
+                    . 'DB_first_level FROM INFORMATION_SCHEMA.SCHEMATA '
                     . "WHERE `SCHEMA_NAME` < 'pma_test' ) t",
                 'result' => [],
             ],
             [
-                'query'  => "SELECT `SCHEMA_NAME` FROM "
-                    . "`INFORMATION_SCHEMA`.`SCHEMATA`, "
-                    . "(SELECT DB_first_level FROM ( SELECT DISTINCT "
+                'query'  => 'SELECT `SCHEMA_NAME` FROM '
+                    . '`INFORMATION_SCHEMA`.`SCHEMATA`, '
+                    . '(SELECT DB_first_level FROM ( SELECT DISTINCT '
                     . "SUBSTRING_INDEX(SCHEMA_NAME, '_', 1) DB_first_level FROM "
-                    . "INFORMATION_SCHEMA.SCHEMATA WHERE TRUE ) t "
-                    . "ORDER BY DB_first_level ASC LIMIT , 100) t2 WHERE TRUE AND "
+                    . 'INFORMATION_SCHEMA.SCHEMATA WHERE TRUE ) t '
+                    . 'ORDER BY DB_first_level ASC LIMIT , 100) t2 WHERE TRUE AND '
                     . "1 = LOCATE(CONCAT(DB_first_level, '_'), "
                     . "CONCAT(SCHEMA_NAME, '_')) ORDER BY SCHEMA_NAME ASC",
                 'result' => [],
diff --git a/test/classes/SystemDatabaseTest.php b/test/classes/SystemDatabaseTest.php
index ddbb708f83..50d9cbf9d3 100644
--- a/test/classes/SystemDatabaseTest.php
+++ b/test/classes/SystemDatabaseTest.php
@@ -50,9 +50,9 @@ class SystemDatabaseTest extends PmaTestCase
         //_SESSION
         $_SESSION['relation'][$GLOBALS['server']] = [
             'PMA_VERSION' => PMA_VERSION,
-            'table_coords' => "table_name",
+            'table_coords' => 'table_name',
             'displaywork' => 'displaywork',
-            'db' => "information_schema",
+            'db' => 'information_schema',
             'table_info' => 'table_info',
             'relwork' => 'relwork',
             'commwork' => 'commwork',
@@ -66,12 +66,12 @@ class SystemDatabaseTest extends PmaTestCase
             ->will(
                 $this->returnValue(
                     [
-                        'table_name' => "table_name",
-                        'column_name' => "column_name",
-                        'comment' => "comment",
-                        'mimetype' => "mimetype",
-                        'transformation' => "transformation",
-                        'transformation_options' => "transformation_options",
+                        'table_name' => 'table_name',
+                        'column_name' => 'column_name',
+                        'comment' => 'comment',
+                        'mimetype' => 'mimetype',
+                        'transformation' => 'transformation',
+                        'transformation_options' => 'transformation_options',
                     ]
                 )
             );
@@ -87,7 +87,7 @@ class SystemDatabaseTest extends PmaTestCase
      */
     public function testPMAGetExistingTransformationData()
     {
-        $db = "PMA_db";
+        $db = 'PMA_db';
         $ret = $this->sysDb->getExistingTransformationData($db);
 
         //validate that is the same as $GLOBALS['dbi']->tryQuery
@@ -105,15 +105,15 @@ class SystemDatabaseTest extends PmaTestCase
      */
     public function testPMAGetNewTransformationDataSql()
     {
-        $db = "PMA_db";
+        $db = 'PMA_db';
         $pma_transformation_data = [];
         $column_map = [
             [
-                "table_name" => "table_name",
-                "refering_column" => "column_name",
+                'table_name' => 'table_name',
+                'refering_column' => 'column_name',
             ],
         ];
-        $view_name = "view_name";
+        $view_name = 'view_name';
 
         $ret = $this->sysDb->getNewTransformationDataSql(
             $pma_transformation_data,
@@ -122,9 +122,9 @@ class SystemDatabaseTest extends PmaTestCase
             $db
         );
 
-        $sql = "INSERT INTO `information_schema`.`column_info` "
-            . "(`db_name`, `table_name`, `column_name`, `comment`, `mimetype`, "
-            . "`transformation`, `transformation_options`) VALUES "
+        $sql = 'INSERT INTO `information_schema`.`column_info` '
+            . '(`db_name`, `table_name`, `column_name`, `comment`, `mimetype`, '
+            . '`transformation`, `transformation_options`) VALUES '
             . "('PMA_db', 'view_name', 'column_name', 'comment', 'mimetype', "
             . "'transformation', 'transformation_options')";
 
diff --git a/test/classes/TableTest.php b/test/classes/TableTest.php
index db517ddd5f..5e6a31fd38 100644
--- a/test/classes/TableTest.php
+++ b/test/classes/TableTest.php
@@ -38,11 +38,11 @@ class TableTest extends PmaTestCase
         $GLOBALS['cfg']['Server']['DisableIS'] = false;
         $GLOBALS['cfg']['MaxExactCount'] = 100;
         $GLOBALS['cfg']['MaxExactCountViews'] = 100;
-        $GLOBALS['cfg']['Server']['pmadb'] = "pmadb";
+        $GLOBALS['cfg']['Server']['pmadb'] = 'pmadb';
         $GLOBALS['sql_auto_increment'] = true;
         $GLOBALS['sql_if_not_exists'] = true;
         $GLOBALS['sql_drop_table'] = true;
-        $GLOBALS['cfg']['Server']['table_uiprefs'] = "pma__table_uiprefs";
+        $GLOBALS['cfg']['Server']['table_uiprefs'] = 'pma__table_uiprefs';
 
         $relation = new Relation($GLOBALS['dbi']);
         $GLOBALS['cfgRelation'] = $relation->getRelationsParam();
@@ -91,7 +91,7 @@ class TableTest extends PmaTestCase
             WHERE TABLE_SCHEMA = 'db_data'
                 AND TABLE_NAME = 'table_data'";
 
-        $getUniqueColumns_sql = "select unique column";
+        $getUniqueColumns_sql = 'select unique column';
 
         $fetchResult = [
             [
@@ -229,14 +229,14 @@ class TableTest extends PmaTestCase
         $dbi->expects($this->any())->method('fetchValue')
             ->will(
                 $this->returnValue(
-                    "CREATE TABLE `PMA`.`PMA_BookMark_2` (
+                    'CREATE TABLE `PMA`.`PMA_BookMark_2` (
                     `id` int(11) NOT NULL AUTO_INCREMENT,
                     `username` text NOT NULL
-                    )"
+                    )'
                 )
             );
 
-        $dbi->_table_cache["PMA"]["PMA_BookMark"] = [
+        $dbi->_table_cache['PMA']['PMA_BookMark'] = [
             'ENGINE' => true,
             'Create_time' => true,
             'TABLE_TYPE' => true,
@@ -266,25 +266,25 @@ class TableTest extends PmaTestCase
 
         $triggers = [
             [
-                "name" => "name1",
-                "create" => "crate1",
+                'name' => 'name1',
+                'create' => 'crate1',
             ],
             [
-                "name" => "name2",
-                "create" => "crate2",
+                'name' => 'name2',
+                'create' => 'crate2',
             ],
             [
-                "name" => "name3",
-                "create" => "crate3",
+                'name' => 'name3',
+                'create' => 'crate3',
             ],
         ];
 
         $dbi->expects($this->any())->method('getTriggers')
             ->will($this->returnValue($triggers));
 
-        $create_sql = "CREATE TABLE `PMA`.`PMA_BookMark_2` (
+        $create_sql = 'CREATE TABLE `PMA`.`PMA_BookMark_2` (
                     `id` int(11) NOT NULL AUTO_INCREMENT,
-                    `username` text NOT NULL";
+                    `username` text NOT NULL';
         $dbi->expects($this->any())->method('query')
             ->will($this->returnValue($create_sql));
 
@@ -297,7 +297,7 @@ class TableTest extends PmaTestCase
         $dbi->expects($this->any())->method('fetchAssoc')
             ->will($this->returnValue(false));
 
-        $value = ["Auto_increment" => "Auto_increment"];
+        $value = ['Auto_increment' => 'Auto_increment'];
         $dbi->expects($this->any())->method('fetchSingleRow')
             ->will($this->returnValue($value));
 
@@ -328,7 +328,7 @@ class TableTest extends PmaTestCase
      */
     public function testConstruct()
     {
-        $table = new Table("PMA_BookMark", "PMA");
+        $table = new Table('PMA_BookMark', 'PMA');
         $this->assertEquals(
             'PMA_BookMark',
             $table->__toString()
@@ -356,19 +356,19 @@ class TableTest extends PmaTestCase
     {
         $table = new Table('table1', 'pma_test');
         $this->assertEquals(
-            "table1",
+            'table1',
             $table->getName()
         );
         $this->assertEquals(
-            "`table1`",
+            '`table1`',
             $table->getName(true)
         );
         $this->assertEquals(
-            "pma_test",
+            'pma_test',
             $table->getDbName()
         );
         $this->assertEquals(
-            "`pma_test`",
+            '`pma_test`',
             $table->getDbName(true)
         );
     }
@@ -381,20 +381,20 @@ class TableTest extends PmaTestCase
     public function testGetLastErrorAndMessage()
     {
         $table = new Table('table1', 'pma_test');
-        $table->errors[] = "error1";
-        $table->errors[] = "error2";
-        $table->errors[] = "error3";
+        $table->errors[] = 'error1';
+        $table->errors[] = 'error2';
+        $table->errors[] = 'error3';
 
-        $table->messages[] = "messages1";
-        $table->messages[] = "messages2";
-        $table->messages[] = "messages3";
+        $table->messages[] = 'messages1';
+        $table->messages[] = 'messages2';
+        $table->messages[] = 'messages3';
 
         $this->assertEquals(
-            "error3",
+            'error3',
             $table->getLastError()
         );
         $this->assertEquals(
-            "messages3",
+            'messages3',
             $table->getLastMessage()
         );
     }
@@ -507,8 +507,8 @@ class TableTest extends PmaTestCase
     public function testGenerateFieldSpec()
     {
         //type is BIT
-        $name = "PMA_name";
-        $type = "BIT";
+        $name = 'PMA_name';
+        $type = 'BIT';
         $length = '12';
         $attribute = 'PMA_attribute';
         $collation = 'PMA_collation';
@@ -543,7 +543,7 @@ class TableTest extends PmaTestCase
         );
 
         //type is DOUBLE
-        $type = "DOUBLE";
+        $type = 'DOUBLE';
         $query = Table::generateFieldSpec(
             $name,
             $type,
@@ -566,7 +566,7 @@ class TableTest extends PmaTestCase
         );
 
         //type is BOOLEAN
-        $type = "BOOLEAN";
+        $type = 'BOOLEAN';
         $query = Table::generateFieldSpec(
             $name,
             $type,
@@ -583,7 +583,7 @@ class TableTest extends PmaTestCase
             $move_to
         );
         $this->assertEquals(
-            "`PMA_name` BOOLEAN PMA_attribute NULL DEFAULT TRUE "
+            '`PMA_name` BOOLEAN PMA_attribute NULL DEFAULT TRUE '
             . "AUTO_INCREMENT COMMENT 'PMA_comment' FIRST",
             $query
         );
@@ -606,7 +606,7 @@ class TableTest extends PmaTestCase
             $move_to
         );
         $this->assertEquals(
-            "`PMA_name` BOOLEAN PMA_attribute NULL DEFAULT NULL "
+            '`PMA_name` BOOLEAN PMA_attribute NULL DEFAULT NULL '
             . "AUTO_INCREMENT COMMENT 'PMA_comment' FIRST",
             $query
         );
@@ -629,7 +629,7 @@ class TableTest extends PmaTestCase
             $move_to
         );
         $this->assertEquals(
-            "`PMA_name` BOOLEAN PMA_attribute NULL DEFAULT CURRENT_TIMESTAMP "
+            '`PMA_name` BOOLEAN PMA_attribute NULL DEFAULT CURRENT_TIMESTAMP '
             . "AUTO_INCREMENT COMMENT 'PMA_comment' FIRST",
             $query
         );
@@ -652,7 +652,7 @@ class TableTest extends PmaTestCase
             $move_to
         );
         $this->assertEquals(
-            "`PMA_name` BOOLEAN PMA_attribute NULL DEFAULT current_timestamp() "
+            '`PMA_name` BOOLEAN PMA_attribute NULL DEFAULT current_timestamp() '
             . "AUTO_INCREMENT COMMENT 'PMA_comment' FIRST",
             $query
         );
@@ -678,7 +678,7 @@ class TableTest extends PmaTestCase
             $move_to
         );
         $this->assertEquals(
-            "`PMA_name` TIMESTAMP(3) PMA_attribute NULL DEFAULT CURRENT_TIMESTAMP(3) "
+            '`PMA_name` TIMESTAMP(3) PMA_attribute NULL DEFAULT CURRENT_TIMESTAMP(3) '
             . "COMMENT 'PMA_comment' FIRST",
             $query
         );
@@ -704,7 +704,7 @@ class TableTest extends PmaTestCase
             $move_to
         );
         $this->assertEquals(
-            "`PMA_name` BOOLEAN PMA_attribute NULL INCREMENT "
+            '`PMA_name` BOOLEAN PMA_attribute NULL INCREMENT '
             . "COMMENT 'PMA_comment' FIRST",
             $query
         );
@@ -718,23 +718,23 @@ class TableTest extends PmaTestCase
      */
     public function testDuplicateInfo()
     {
-        $work = "PMA_work";
-        $pma_table = "pma_table";
+        $work = 'PMA_work';
+        $pma_table = 'pma_table';
         $get_fields =  [
-            "filed0",
-            "field6",
+            'filed0',
+            'field6',
         ];
         $where_fields = [
-            "field2",
-            "filed5",
+            'field2',
+            'filed5',
         ];
         $new_fields = [
-            "field3",
-            "filed4",
+            'field3',
+            'filed4',
         ];
         $GLOBALS['cfgRelation'][$work] = true;
-        $GLOBALS['cfgRelation']['db'] = "PMA_db";
-        $GLOBALS['cfgRelation'][$pma_table] = "pma_table";
+        $GLOBALS['cfgRelation']['db'] = 'PMA_db';
+        $GLOBALS['cfgRelation'][$pma_table] = 'pma_table';
 
         $ret = Table::duplicateInfo(
             $work,
@@ -790,7 +790,7 @@ class TableTest extends PmaTestCase
 
         $GLOBALS['dbi']->expects($this->any())
             ->method('getCachedTableContent')
-            ->will($this->returnValue(['table_name' => "PMA_BookMark"]));
+            ->will($this->returnValue(['table_name' => 'PMA_BookMark']));
         $tableObj = new Table('PMA_BookMark', 'PMA');
         $this->assertEquals(
             false,
@@ -811,7 +811,7 @@ class TableTest extends PmaTestCase
                     'PMA',
                     'PMA_BookMark',
                 ], null,
-                ['ENGINE' => "MERGE"],
+                ['ENGINE' => 'MERGE'],
             ],
             [
                 [
@@ -819,7 +819,7 @@ class TableTest extends PmaTestCase
                     'PMA_BookMark',
                     'ENGINE',
                 ], null,
-                "MERGE",
+                'MERGE',
             ],
         ];
         $GLOBALS['dbi']->expects($this->any())
@@ -846,7 +846,7 @@ class TableTest extends PmaTestCase
                     'PMA',
                     'PMA_BookMark',
                 ], null,
-                ['ENGINE' => "MRG_MYISAM"],
+                ['ENGINE' => 'MRG_MYISAM'],
             ],
             [
                 [
@@ -854,7 +854,7 @@ class TableTest extends PmaTestCase
                     'PMA_BookMark',
                     'ENGINE',
                 ], null,
-                "MRG_MYISAM",
+                'MRG_MYISAM',
             ],
         ];
         $GLOBALS['dbi']->expects($this->any())
@@ -881,7 +881,7 @@ class TableTest extends PmaTestCase
                     'PMA',
                     'PMA_BookMark',
                 ], null,
-                ['ENGINE' => "ISDB"],
+                ['ENGINE' => 'ISDB'],
             ],
             [
                 [
@@ -889,7 +889,7 @@ class TableTest extends PmaTestCase
                     'PMA_BookMark',
                     'ENGINE',
                 ], null,
-                "ISDB",
+                'ISDB',
             ],
         ];
         $GLOBALS['dbi']->expects($this->any())
@@ -943,7 +943,7 @@ class TableTest extends PmaTestCase
             $move_to
         );
 
-        $expect = "`name` `new_name` VARCHAR(2) new_name CHARACTER SET "
+        $expect = '`name` `new_name` VARCHAR(2) new_name CHARACTER SET '
             . "charset1 NULL DEFAULT 'VARCHAR' "
             . "AUTO_INCREMENT COMMENT 'PMA comment' AFTER `new_name`";
 
@@ -998,7 +998,7 @@ class TableTest extends PmaTestCase
 
         //message
         $this->assertEquals(
-            "Table PMA_BookMark has been renamed to PMA_.BookMark.",
+            'Table PMA_BookMark has been renamed to PMA_.BookMark.',
             $table->getLastMessage()
         );
 
@@ -1011,7 +1011,7 @@ class TableTest extends PmaTestCase
         );
         //message
         $this->assertEquals(
-            "Table PMA_.BookMark has been renamed to PMA_BookMark_new.",
+            'Table PMA_.BookMark has been renamed to PMA_BookMark_new.',
             $table->getLastMessage()
         );
     }
@@ -1079,12 +1079,12 @@ class TableTest extends PmaTestCase
 
         $dbi->expects($this->once())
             ->method('tryQuery')
-            ->with("SELECT * FROM `db`.`table` LIMIT 1")
+            ->with('SELECT * FROM `db`.`table` LIMIT 1')
             ->will($this->returnValue('v1'));
 
         $dbi->expects($this->once())
             ->method('getFieldsMeta')
-            ->with("v1")
+            ->with('v1')
             ->will($this->returnValue('movecols'));
 
         $GLOBALS['dbi'] = $dbi;
@@ -1105,16 +1105,16 @@ class TableTest extends PmaTestCase
      */
     public function testGetSQLToCreateForeignKey()
     {
-        $table = "PMA_table";
+        $table = 'PMA_table';
         $field = [
-            "PMA_field1",
-            "PMA_field2",
+            'PMA_field1',
+            'PMA_field2',
         ];
-        $foreignDb = "foreignDb";
-        $foreignTable = "foreignTable";
+        $foreignDb = 'foreignDb';
+        $foreignTable = 'foreignTable';
         $foreignField = [
-            "foreignField1",
-            "foreignField2",
+            'foreignField1',
+            'foreignField2',
         ];
 
         $class = new ReflectionClass(Table::class);
@@ -1168,18 +1168,18 @@ class TableTest extends PmaTestCase
      */
     public function testGetSqlQueryForIndexCreateOrEdit()
     {
-        $db = "pma_db";
-        $table = "pma_table";
+        $db = 'pma_db';
+        $table = 'pma_table';
         $index = new Index();
         $error = false;
 
-        $_POST['old_index'] = "PRIMARY";
+        $_POST['old_index'] = 'PRIMARY';
 
         $table = new Table($table, $db);
         $sql = $table->getSqlQueryForIndexCreateOrEdit($index, $error);
 
         $this->assertEquals(
-            "ALTER TABLE `pma_db`.`pma_table` DROP PRIMARY KEY, ADD UNIQUE ;",
+            'ALTER TABLE `pma_db`.`pma_table` DROP PRIMARY KEY, ADD UNIQUE ;',
             $sql
         );
     }
@@ -1303,8 +1303,8 @@ class TableTest extends PmaTestCase
                 ],
                 null,
                 [
-                    'Comment' => "Comment222",
-                    'TABLE_TYPE' => "VIEW",
+                    'Comment' => 'Comment222',
+                    'TABLE_TYPE' => 'VIEW',
                 ],
             ],
             [
@@ -1345,7 +1345,7 @@ class TableTest extends PmaTestCase
         $table = new Table($table_name, $db);
 
         $property = Table::PROP_COLUMN_ORDER;
-        $value = "UiProp_value";
+        $value = 'UiProp_value';
         $table_create_time = null;
         $table->setUiProp($property, $value, $table_create_time);
 
@@ -1382,9 +1382,9 @@ class TableTest extends PmaTestCase
         $source_db = 'PMA';
         $target_table = 'PMA_BookMark_new';
         $target_db = 'PMA_new';
-        $what = "dataonly";
+        $what = 'dataonly';
         $move = true;
-        $mode = "one_table";
+        $mode = 'one_table';
 
         $GLOBALS['dbi']->expects($this->any())->method('getTable')
             ->will($this->returnValue(new Table($target_table, $target_db)));
@@ -1407,14 +1407,14 @@ class TableTest extends PmaTestCase
             $expect,
             $return
         );
-        $sql_query = "INSERT INTO `PMA_new`.`PMA_BookMark_new`(`COLUMN_NAME1`)"
-            . " SELECT `COLUMN_NAME1` FROM "
-            . "`PMA`.`PMA_BookMark`";
+        $sql_query = 'INSERT INTO `PMA_new`.`PMA_BookMark_new`(`COLUMN_NAME1`)'
+            . ' SELECT `COLUMN_NAME1` FROM '
+            . '`PMA`.`PMA_BookMark`';
         $this->assertStringContainsString(
             $sql_query,
             $GLOBALS['sql_query']
         );
-        $sql_query = "DROP VIEW `PMA`.`PMA_BookMark`";
+        $sql_query = 'DROP VIEW `PMA`.`PMA_BookMark`';
         $this->assertStringContainsString(
             $sql_query,
             $GLOBALS['sql_query']
@@ -1436,14 +1436,14 @@ class TableTest extends PmaTestCase
             $expect,
             $return
         );
-        $sql_query = "INSERT INTO `PMA_new`.`PMA_BookMark_new`(`COLUMN_NAME1`)"
-            . " SELECT `COLUMN_NAME1` FROM "
-            . "`PMA`.`PMA_BookMark`";
+        $sql_query = 'INSERT INTO `PMA_new`.`PMA_BookMark_new`(`COLUMN_NAME1`)'
+            . ' SELECT `COLUMN_NAME1` FROM '
+            . '`PMA`.`PMA_BookMark`';
         $this->assertStringContainsString(
             $sql_query,
             $GLOBALS['sql_query']
         );
-        $sql_query = "DROP VIEW `PMA`.`PMA_BookMark`";
+        $sql_query = 'DROP VIEW `PMA`.`PMA_BookMark`';
         $this->assertStringNotContainsString(
             $sql_query,
             $GLOBALS['sql_query']
diff --git a/test/classes/ThemeTest.php b/test/classes/ThemeTest.php
index 70f13eaacc..26e991df08 100644
--- a/test/classes/ThemeTest.php
+++ b/test/classes/ThemeTest.php
@@ -189,11 +189,11 @@ class ThemeTest extends PmaTestCase
             'Version 0.0.0.0 by default'
         );
 
-        $this->object->setVersion("1.2.3.4");
+        $this->object->setVersion('1.2.3.4');
         $this->assertEquals('1.2.3.4', $this->object->getVersion());
 
-        $this->assertFalse($this->object->checkVersion("0.0.1.1"));
-        $this->assertTrue($this->object->checkVersion("2.0.1.1"));
+        $this->assertFalse($this->object->checkVersion('0.0.1.1'));
+        $this->assertTrue($this->object->checkVersion('2.0.1.1'));
     }
 
     /**
diff --git a/test/classes/TrackerTest.php b/test/classes/TrackerTest.php
index cd322b5341..21c550037e 100644
--- a/test/classes/TrackerTest.php
+++ b/test/classes/TrackerTest.php
@@ -125,7 +125,7 @@ class TrackerTest extends PmaTestCase
     public function testGetTableName($string, $expected): void
     {
         $reflection = new ReflectionClass('PhpMyAdmin\Tracker');
-        $method = $reflection->getMethod("getTableName");
+        $method = $reflection->getMethod('getTableName');
         $method->setAccessible(true);
 
         $this->assertEquals(
@@ -144,16 +144,16 @@ class TrackerTest extends PmaTestCase
     {
         return [
             [
-                "`tbl`;",
-                "tbl",
+                '`tbl`;',
+                'tbl',
             ],
             [
-                " `pma.table` ",
-                "table",
+                ' `pma.table` ',
+                'table',
             ],
             [
                 " `pma.table\nfoobar` ",
-                "table",
+                'table',
             ],
         ];
     }
@@ -171,7 +171,7 @@ class TrackerTest extends PmaTestCase
         $attr->setValue(false);
 
         $this->assertFalse(
-            Tracker::isTracked("", "")
+            Tracker::isTracked('', '')
         );
 
         Tracker::enable();
@@ -180,17 +180,17 @@ class TrackerTest extends PmaTestCase
         $_SESSION['relation'][$GLOBALS['server']]['trackingwork'] = false;
 
         $this->assertFalse(
-            Tracker::isTracked("", "")
+            Tracker::isTracked('', '')
         );
 
         $_SESSION['relation'][$GLOBALS['server']]['trackingwork'] = true;
 
         $this->assertTrue(
-            Tracker::isTracked("pma_test_db", "pma_test_table")
+            Tracker::isTracked('pma_test_db', 'pma_test_table')
         );
 
         $this->assertFalse(
-            Tracker::isTracked("pma_test_db", "pma_test_table2")
+            Tracker::isTracked('pma_test_db', 'pma_test_table2')
         );
     }
 
@@ -203,10 +203,10 @@ class TrackerTest extends PmaTestCase
     public function testGetLogComment()
     {
         $date = Util::date('Y-m-d H:i:s');
-        $GLOBALS['cfg']['Server']['user'] = "pma_test_user";
+        $GLOBALS['cfg']['Server']['user'] = 'pma_test_user';
 
         $this->assertEquals(
-            "# log $date pma_test_user\n",
+            '# log ' . $date . " pma_test_user\n",
             Tracker::getLogComment()
         );
     }
@@ -221,7 +221,7 @@ class TrackerTest extends PmaTestCase
     {
         $GLOBALS['cfg']['Server']['tracking_add_drop_table'] = true;
         $GLOBALS['cfg']['Server']['tracking_add_drop_view'] = true;
-        $GLOBALS['cfg']['Server']['user'] = "pma_test_user";
+        $GLOBALS['cfg']['Server']['user'] = 'pma_test_user';
 
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
             ->disableOriginalConstructor()
@@ -275,7 +275,7 @@ class TrackerTest extends PmaTestCase
 
         $date = Util::date('Y-m-d H:i:s');
 
-        $expectedMainQuery = "/*NOTRACK*/" .
+        $expectedMainQuery = '/*NOTRACK*/' .
         "\nINSERT INTO `pmadb`.`tracking` (db_name, table_name, version, date_created, date_updated," .
         " schema_snapshot, schema_sql, data_sql, tracking ) values (
         'pma_test',
@@ -284,16 +284,16 @@ class TrackerTest extends PmaTestCase
         '" . $date . "',
         '" . $date . "',
         'a:2:{s:7:\"COLUMNS\";a:2:{" .
-        "i:0;a:3:{s:5:\"Field\";s:6:\"field1\";s:4:\"Type\";s:7:\"int(11)\";" .
-        "s:3:\"Key\";s:3:\"PRI\";}" .
-        "i:1;a:3:{s:5:\"Field\";s:6:\"field2\";s:4:\"Type\";s:4:\"text\";" .
-        "s:3:\"Key\";s:0:\"\";}}" .
-        "s:7:\"INDEXES\";a:1:{" .
-        "i:0;a:3:{s:5:\"Table\";s:7:\"pma_tbl\";s:5:\"Field\";s:6:\"field1\";" .
+        'i:0;a:3:{s:5:"Field";s:6:"field1";s:4:"Type";s:7:"int(11)";' .
+        's:3:"Key";s:3:"PRI";}' .
+        'i:1;a:3:{s:5:"Field";s:6:"field2";s:4:"Type";s:4:"text";' .
+        's:3:"Key";s:0:"";}}' .
+        's:7:"INDEXES";a:1:{' .
+        'i:0;a:3:{s:5:"Table";s:7:"pma_tbl";s:5:"Field";s:6:"field1";' .
         "s:3:\"Key\";s:7:\"PRIMARY\";}}}',
-        '# log " . $date . " pma_test_user" .
+        '# log " . $date . ' pma_test_user' .
         "\nDROP VIEW IF EXISTS `pma_tbl`;" .
-        "\n# log " . $date . " pma_test_user" .
+        "\n# log " . $date . ' pma_test_user' .
         "\n\n;" .
         "\n',
         '" .
@@ -338,7 +338,7 @@ class TrackerTest extends PmaTestCase
             ->getMock();
 
         $sql_query = "/*NOTRACK*/\n"
-            . "DELETE FROM `pmadb`.`tracking`"
+            . 'DELETE FROM `pmadb`.`tracking`'
             . " WHERE `db_name` = 'testdb'"
             . " AND `table_name` = 'testtable'";
 
@@ -351,7 +351,7 @@ class TrackerTest extends PmaTestCase
 
         $GLOBALS['dbi'] = $dbi;
         $this->assertEquals(
-            Tracker::deleteTracking("testdb", "testtable"),
+            Tracker::deleteTracking('testdb', 'testtable'),
             'executed'
         );
     }
@@ -366,7 +366,7 @@ class TrackerTest extends PmaTestCase
     {
         $GLOBALS['cfg']['Server']['tracking_add_drop_table'] = true;
         $GLOBALS['cfg']['Server']['tracking_add_drop_view'] = true;
-        $GLOBALS['cfg']['Server']['user'] = "pma_test_user";
+        $GLOBALS['cfg']['Server']['user'] = 'pma_test_user';
 
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
             ->disableOriginalConstructor()
@@ -374,7 +374,7 @@ class TrackerTest extends PmaTestCase
 
         $date = Util::date('Y-m-d H:i:s');
 
-        $expectedMainQuery = "/*NOTRACK*/" .
+        $expectedMainQuery = '/*NOTRACK*/' .
         "\nINSERT INTO `pmadb`.`tracking` (db_name, table_name, version, date_created, date_updated," .
         " schema_snapshot, schema_sql, data_sql, tracking ) values (
         'pma_test',
@@ -383,7 +383,7 @@ class TrackerTest extends PmaTestCase
         '" . $date . "',
         '" . $date . "',
         '',
-        '# log " . $date . " pma_test_user" .
+        '# log " . $date . ' pma_test_user' .
         "\nSHOW DATABASES',
         '" .
         "\n',
@@ -392,7 +392,7 @@ class TrackerTest extends PmaTestCase
         $dbi->expects($this->exactly(1))
             ->method('query')
             ->with($expectedMainQuery, DatabaseInterface::CONNECT_CONTROL, 0, false)
-            ->will($this->returnValue("executed"));
+            ->will($this->returnValue('executed'));
 
         $dbi->expects($this->any())->method('escapeString')
             ->will($this->returnArgument(0));
@@ -430,7 +430,7 @@ class TrackerTest extends PmaTestCase
             ->disableOriginalConstructor()
             ->getMock();
 
-        $sql_query = " UPDATE `pmadb`.`tracking` SET `tracking_active` = " .
+        $sql_query = ' UPDATE `pmadb`.`tracking` SET `tracking_active` = ' .
         "'" . $new_state . "' " .
         " WHERE `db_name` = '" . $dbname . "' " .
         " AND `table_name` = '" . $tablename . "' " .
@@ -439,7 +439,7 @@ class TrackerTest extends PmaTestCase
         $dbi->expects($this->exactly(1))
             ->method('query')
             ->with($sql_query, DatabaseInterface::CONNECT_CONTROL, 0, false)
-            ->will($this->returnValue("executed"));
+            ->will($this->returnValue('executed'));
 
         $dbi->expects($this->any())->method('escapeString')
             ->will($this->returnArgument(0));
@@ -458,9 +458,9 @@ class TrackerTest extends PmaTestCase
                 $version,
                 $new_state
             );
-        } elseif ($type == "activate") {
+        } elseif ($type == 'activate') {
             $result = Tracker::activateTracking($dbname, $tablename, $version);
-        } elseif ($type == "deactivate") {
+        } elseif ($type == 'deactivate') {
             $result = Tracker::deactivateTracking($dbname, $tablename, $version);
         }
 
@@ -479,14 +479,14 @@ class TrackerTest extends PmaTestCase
     public function testChangeTrackingData()
     {
         $this->assertFalse(
-            Tracker::changeTrackingData("", "", "", "", "")
+            Tracker::changeTrackingData('', '', '', '', '')
         );
 
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
             ->disableOriginalConstructor()
             ->getMock();
 
-        $sql_query_1 = " UPDATE `pmadb`.`tracking`" .
+        $sql_query_1 = ' UPDATE `pmadb`.`tracking`' .
         " SET `schema_sql` = '# new_data_processed' " .
         " WHERE `db_name` = 'pma_db' " .
         " AND `table_name` = 'pma_table' " .
@@ -505,9 +505,9 @@ class TrackerTest extends PmaTestCase
             ],
         ];
 
-        $sql_query_2 = " UPDATE `pmadb`.`tracking`" .
-        " SET `data_sql` = '# log $date user1test_statement1\n" .
-        "# log $date user2test_statement2\n' " .
+        $sql_query_2 = ' UPDATE `pmadb`.`tracking`' .
+        " SET `data_sql` = '# log " . $date . " user1test_statement1\n" .
+        '# log ' . $date . " user2test_statement2\n' " .
         " WHERE `db_name` = 'pma_db' " .
         " AND `table_name` = 'pma_table' " .
         " AND `version` = '1.0' ";
@@ -521,14 +521,14 @@ class TrackerTest extends PmaTestCase
                             DatabaseInterface::CONNECT_CONTROL,
                             0,
                             false,
-                            "executed_1",
+                            'executed_1',
                         ],
                         [
                             $sql_query_2,
                             DatabaseInterface::CONNECT_CONTROL,
                             0,
                             false,
-                            "executed_2",
+                            'executed_2',
                         ],
                     ]
                 )
@@ -546,7 +546,7 @@ class TrackerTest extends PmaTestCase
                 'pma_table',
                 '1.0',
                 'DDL',
-                "# new_data_processed"
+                '# new_data_processed'
             )
         );
 
@@ -602,11 +602,11 @@ class TrackerTest extends PmaTestCase
 
         $dbi->expects($this->once())
             ->method('query')
-            ->will($this->returnValue("executed_1"));
+            ->will($this->returnValue('executed_1'));
 
         $dbi->expects($this->once())
             ->method('fetchAssoc')
-            ->with("executed_1")
+            ->with('executed_1')
             ->will($this->returnValue($fetchArrayReturn));
 
         $dbi->expects($this->any())
@@ -623,15 +623,15 @@ class TrackerTest extends PmaTestCase
                             "pma\'table",
                         ],
                         [
-                            "1.0",
-                            "1.0",
+                            '1.0',
+                            '1.0',
                         ],
                     ]
                 )
             );
 
         $GLOBALS['dbi'] = $dbi;
-        $result = Tracker::getTrackedData("pma'db", "pma'table", "1.0");
+        $result = Tracker::getTrackedData("pma'db", "pma'table", '1.0');
 
         $this->assertEquals(
             $expectedArray,
@@ -648,11 +648,11 @@ class TrackerTest extends PmaTestCase
     {
         $fetchArrayReturn = [
             [
-                "schema_sql" => "# log 20-03-2013 23:33:58 user1\nstat1" .
+                'schema_sql' => "# log 20-03-2013 23:33:58 user1\nstat1" .
                 "# log 20-03-2013 23:39:58 user2\n",
-                "data_sql" => "# log ",
-                "schema_snapshot" => "dataschema",
-                "tracking" => "SELECT, DELETE",
+                'data_sql' => '# log ',
+                'schema_snapshot' => 'dataschema',
+                'tracking' => 'SELECT, DELETE',
             ],
         ];
 
@@ -669,22 +669,22 @@ class TrackerTest extends PmaTestCase
                     [
                         'date' => '20-03-2013 23:39:58',
                         'username' => 'user2',
-                        'statement' => "",
+                        'statement' => '',
                     ],
                 ],
                 'dmlog' => [],
-                "schema_snapshot" => "dataschema",
-                "tracking" => "SELECT, DELETE",
+                'schema_snapshot' => 'dataschema',
+                'tracking' => 'SELECT, DELETE',
             ],
         ];
 
         $fetchArrayReturn[1] = [
-            "schema_sql" => "# log 20-03-2012 23:33:58 user1\n" .
+            'schema_sql' => "# log 20-03-2012 23:33:58 user1\n" .
             "# log 20-03-2012 23:39:58 user2\n",
-            "data_sql" => "# log 20-03-2013 23:33:58 user3\n" .
+            'data_sql' => "# log 20-03-2013 23:33:58 user3\n" .
             "# log 20-03-2013 23:39:58 user4\n",
-            "schema_snapshot" => "dataschema",
-            "tracking" => "SELECT, DELETE",
+            'schema_snapshot' => 'dataschema',
+            'tracking' => 'SELECT, DELETE',
         ];
 
         $data[1] = [
@@ -694,28 +694,28 @@ class TrackerTest extends PmaTestCase
                 [
                     'date' => '20-03-2012 23:33:58',
                     'username' => 'user1',
-                    'statement' => "",
+                    'statement' => '',
                 ],
                 [
                     'date' => '20-03-2012 23:39:58',
                     'username' => 'user2',
-                    'statement' => "",
+                    'statement' => '',
                 ],
             ],
             'dmlog' => [
                 [
                     'date' => '20-03-2013 23:33:58',
                     'username' => 'user3',
-                    'statement' => "",
+                    'statement' => '',
                 ],
                 [
                     'date' => '20-03-2013 23:39:58',
                     'username' => 'user4',
-                    'statement' => "",
+                    'statement' => '',
                 ],
             ],
-            "schema_snapshot" => "dataschema",
-            "tracking" => "SELECT, DELETE",
+            'schema_snapshot' => 'dataschema',
+            'tracking' => 'SELECT, DELETE',
         ];
         return [
             [
@@ -802,128 +802,128 @@ class TrackerTest extends PmaTestCase
         );
         */
         $query[] = [
-            "CREATE VIEW v AS SELECT * FROM t;",
-            "DDL",
-            "CREATE VIEW",
-            "v",
+            'CREATE VIEW v AS SELECT * FROM t;',
+            'DDL',
+            'CREATE VIEW',
+            'v',
         ];
         $query[] = [
-            "ALTER VIEW db1.v AS SELECT col1, col2, col3, col4 FROM t",
-            "DDL",
-            "ALTER VIEW",
-            "v",
+            'ALTER VIEW db1.v AS SELECT col1, col2, col3, col4 FROM t',
+            'DDL',
+            'ALTER VIEW',
+            'v',
         ];
         $query[] = [
-            "DROP VIEW db1.v;",
-            "DDL",
-            "DROP VIEW",
-            "v",
+            'DROP VIEW db1.v;',
+            'DDL',
+            'DROP VIEW',
+            'v',
         ];
         $query[] = [
-            "DROP VIEW IF EXISTS db1.v;",
-            "DDL",
-            "DROP VIEW",
-            "v",
+            'DROP VIEW IF EXISTS db1.v;',
+            'DDL',
+            'DROP VIEW',
+            'v',
         ];
         $query[] = [
-            "CREATE DATABASE db1;",
-            "DDL",
-            "CREATE DATABASE",
-            "",
-            "db1",
+            'CREATE DATABASE db1;',
+            'DDL',
+            'CREATE DATABASE',
+            '',
+            'db1',
         ];
         $query[] = [
-            "ALTER DATABASE db1;",
-            "DDL",
-            "ALTER DATABASE",
-            "",
+            'ALTER DATABASE db1;',
+            'DDL',
+            'ALTER DATABASE',
+            '',
         ];
         $query[] = [
-            "DROP DATABASE db1;",
-            "DDL",
-            "DROP DATABASE",
-            "",
-            "db1",
+            'DROP DATABASE db1;',
+            'DDL',
+            'DROP DATABASE',
+            '',
+            'db1',
         ];
         $query[] = [
-            "CREATE TABLE db1.t1 (c1 INT);",
-            "DDL",
-            "CREATE TABLE",
-            "t1",
+            'CREATE TABLE db1.t1 (c1 INT);',
+            'DDL',
+            'CREATE TABLE',
+            't1',
         ];
         $query[] =  [
-            "ALTER TABLE db1.t1 ADD c2 TEXT;",
-            "DDL",
-            "ALTER TABLE",
-            "t1",
+            'ALTER TABLE db1.t1 ADD c2 TEXT;',
+            'DDL',
+            'ALTER TABLE',
+            't1',
         ];
         $query[] =  [
-            "DROP TABLE db1.t1",
-            "DDL",
-            "DROP TABLE",
-            "t1",
+            'DROP TABLE db1.t1',
+            'DDL',
+            'DROP TABLE',
+            't1',
         ];
         $query[] =  [
-            "DROP TABLE IF EXISTS db1.t1",
-            "DDL",
-            "DROP TABLE",
-            "t1",
+            'DROP TABLE IF EXISTS db1.t1',
+            'DDL',
+            'DROP TABLE',
+            't1',
         ];
         $query[] =  [
-            "CREATE INDEX ind ON db1.t1 (c2(10));",
-            "DDL",
-            "CREATE INDEX",
-            "t1",
+            'CREATE INDEX ind ON db1.t1 (c2(10));',
+            'DDL',
+            'CREATE INDEX',
+            't1',
         ];
         $query[] =  [
-            "CREATE UNIQUE INDEX ind ON db1.t1 (c2(10));",
-            "DDL",
-            "CREATE INDEX",
-            "t1",
+            'CREATE UNIQUE INDEX ind ON db1.t1 (c2(10));',
+            'DDL',
+            'CREATE INDEX',
+            't1',
         ];
         $query[] =  [
-            "CREATE SPATIAL INDEX ind ON db1.t1 (c2(10));",
-            "DDL",
-            "CREATE INDEX",
-            "t1",
+            'CREATE SPATIAL INDEX ind ON db1.t1 (c2(10));',
+            'DDL',
+            'CREATE INDEX',
+            't1',
         ];
         $query[] =  [
-            "DROP INDEX ind ON db1.t1;",
-            "DDL",
-            "DROP INDEX",
-            "t1",
+            'DROP INDEX ind ON db1.t1;',
+            'DDL',
+            'DROP INDEX',
+            't1',
         ];
         $query[] =  [
-            "RENAME TABLE db1.t1 TO db1.t2",
-            "DDL",
-            "RENAME TABLE",
-            "t1",
-            "",
-            "t2",
+            'RENAME TABLE db1.t1 TO db1.t2',
+            'DDL',
+            'RENAME TABLE',
+            't1',
+            '',
+            't2',
         ];
         $query[] =  [
-            "UPDATE db1.t1 SET a = 2",
-            "DML",
-            "UPDATE",
-            "t1",
+            'UPDATE db1.t1 SET a = 2',
+            'DML',
+            'UPDATE',
+            't1',
         ];
         $query[] =  [
-            "INSERT INTO db1.t1 (a, b, c) VALUES(1, 2, 3)",
-            "DML",
-            "INSERT",
-            "t1",
+            'INSERT INTO db1.t1 (a, b, c) VALUES(1, 2, 3)',
+            'DML',
+            'INSERT',
+            't1',
         ];
         $query[] =  [
-            "DELETE FROM db1.t1",
-            "DML",
-            "DELETE",
-            "t1",
+            'DELETE FROM db1.t1',
+            'DML',
+            'DELETE',
+            't1',
         ];
         $query[] =  [
-            "TRUNCATE db1.t1",
-            "DML",
-            "TRUNCATE",
-            "t1",
+            'TRUNCATE db1.t1',
+            'DML',
+            'TRUNCATE',
+            't1',
         ];
 
         return $query;
diff --git a/test/classes/TrackingTest.php b/test/classes/TrackingTest.php
index 7404010543..d2de222a19 100644
--- a/test/classes/TrackingTest.php
+++ b/test/classes/TrackingTest.php
@@ -40,12 +40,12 @@ class TrackingTest extends TestCase
          * SET these to avoid undefined index error
          */
         $GLOBALS['server'] = 1;
-        $GLOBALS['db'] = "PMA_db";
-        $GLOBALS['table'] = "PMA_table";
-        $GLOBALS['cfg']['ServerDefault'] = "server";
+        $GLOBALS['db'] = 'PMA_db';
+        $GLOBALS['table'] = 'PMA_table';
+        $GLOBALS['cfg']['ServerDefault'] = 'server';
         $GLOBALS['cfg']['ActionLinksMode'] = 'both';
         $GLOBALS['cfg']['MaxCharactersInDisplayedSQL'] = 1000;
-        $GLOBALS['cfg']['NavigationTreeTableSeparator'] = "_";
+        $GLOBALS['cfg']['NavigationTreeTableSeparator'] = '_';
 
         $_SESSION['relation'][$GLOBALS['server']] = [
             'PMA_VERSION' => PMA_VERSION,
@@ -60,7 +60,7 @@ class TrackingTest extends TestCase
             ->disableOriginalConstructor()
             ->getMock();
 
-        $fetchArray = ['version' => "10"];
+        $fetchArray = ['version' => '10'];
         $dbi->expects($this->any())
             ->method('fetchArray')
             ->will($this->returnValue($fetchArray));
@@ -87,19 +87,19 @@ class TrackingTest extends TestCase
     {
         $data = [
             [
-                "date" => "20120102",
-                "username" => "username1",
-                "statement" => "statement1",
+                'date' => '20120102',
+                'username' => 'username1',
+                'statement' => 'statement1',
             ],
             [
-                "date" => "20130102",
-                "username" => "username2",
-                "statement" => "statement2",
+                'date' => '20130102',
+                'username' => 'username2',
+                'statement' => 'statement2',
             ],
         ];
         $filter_ts_from = 0;
         $filter_ts_to = 999999999999;
-        $filter_users = ["username1"];
+        $filter_users = ['username1'];
 
         $ret = $this->tracking->filter(
             $data,
@@ -127,33 +127,33 @@ class TrackingTest extends TestCase
     public function testExtractTableNames()
     {
         $table_list = [
-            "hello_" => [
-                "is_group" => 1,
-                "lovely_" => [
-                    "is_group" => 1,
-                    "hello_lovely_world" => [
-                        "Name" => "hello_lovely_world",
+            'hello_' => [
+                'is_group' => 1,
+                'lovely_' => [
+                    'is_group' => 1,
+                    'hello_lovely_world' => [
+                        'Name' => 'hello_lovely_world',
                     ],
-                    "hello_lovely_world2" => [
-                        "Name" => "hello_lovely_world2",
+                    'hello_lovely_world2' => [
+                        'Name' => 'hello_lovely_world2',
                     ],
                 ],
-                "hello_world" => [
-                    "Name" => "hello_world",
+                'hello_world' => [
+                    'Name' => 'hello_world',
                 ],
             ],
         ];
         $untracked_tables = $this->tracking->extractTableNames($table_list, 'db', true);
         $this->assertContains(
-            "hello_world",
+            'hello_world',
             $untracked_tables
         );
         $this->assertContains(
-            "hello_lovely_world",
+            'hello_lovely_world',
             $untracked_tables
         );
         $this->assertContains(
-            "hello_lovely_world2",
+            'hello_lovely_world2',
             $untracked_tables
         );
     }
@@ -166,8 +166,8 @@ class TrackingTest extends TestCase
     {
         $last_version = 3;
         $url_params = [];
-        $pmaThemeImage = "themePath/img";
-        $text_dir = "ltr";
+        $pmaThemeImage = 'themePath/img';
+        $text_dir = 'ltr';
 
         // Mock dbi
         $dbi_old = $GLOBALS['dbi'];
@@ -231,7 +231,7 @@ class TrackingTest extends TestCase
          * test versions table
          */
          $this->assertStringContainsString(
-             "<td>date_created</td>",
+             '<td>date_created</td>',
              $html
          );
          $this->assertStringContainsString(
@@ -309,11 +309,11 @@ class TrackingTest extends TestCase
      */
     public function testGetTableLastVersionNumber()
     {
-        $sql_result = "sql_result";
+        $sql_result = 'sql_result';
         $last_version = $this->tracking->getTableLastVersionNumber($sql_result);
 
         $this->assertEquals(
-            "10",
+            '10',
             $last_version
         );
     }
@@ -347,7 +347,7 @@ class TrackingTest extends TestCase
                 'Field' => 'Field1',
                 'Type' => 'Type1',
                 'Collation' => 'Collation1',
-                "Null" => 'YES',
+                'Null' => 'YES',
                 'Extra' => 'Extra1',
                 'Key' => 'PRI',
                 'Comment' => 'Comment1',
@@ -356,7 +356,7 @@ class TrackingTest extends TestCase
                 'Field' => 'Field2',
                 'Type' => 'Type2',
                 'Collation' => 'Collation2',
-                "Null" => 'No',
+                'Null' => 'No',
                 'Extra' => 'Extra2',
                 'Key' => 'Key2',
                 'Comment' => 'Comment2',
@@ -458,9 +458,9 @@ class TrackingTest extends TestCase
     public function testGetHtmlForTrackingReportr()
     {
         $_POST['version'] = 10;
-        $_POST['date_from'] = "date_from";
-        $_POST['date_to'] = "date_to";
-        $_POST['users'] = "users";
+        $_POST['date_from'] = 'date_from';
+        $_POST['date_to'] = 'date_to';
+        $_POST['users'] = 'users';
         $_POST['logtype'] = 'logtype';
         $data = [
             'tracking' => 'tracking',
@@ -555,7 +555,7 @@ class TrackingTest extends TestCase
      */
     public function testGetHtmlForDataManipulationStatements()
     {
-        $_POST['version'] = "10";
+        $_POST['version'] = '10';
         $data = [
             'tracking' => 'tracking',
             'dmlog' => [
@@ -569,10 +569,10 @@ class TrackingTest extends TestCase
         ];
         $url_params = [];
         $ddlog_count = 10;
-        $drop_image_or_text = "text";
+        $drop_image_or_text = 'text';
         $filter_ts_to = 9999999999;
         $filter_ts_from = 0;
-        $filter_users = ["*"];
+        $filter_users = ['*'];
 
         $html = $this->tracking->getHtmlForDataManipulationStatements(
             $data,
@@ -618,7 +618,7 @@ class TrackingTest extends TestCase
      */
     public function testGetHtmlForDataDefinitionStatements()
     {
-        $_POST['version'] = "10";
+        $_POST['version'] = '10';
 
         $data = [
             'tracking' => 'tracking',
@@ -631,11 +631,11 @@ class TrackingTest extends TestCase
             ],
             'dmlog' => ['dmlog'],
         ];
-        $filter_users = ["*"];
+        $filter_users = ['*'];
         $filter_ts_to = 9999999999;
         $filter_ts_from = 0;
         $url_params = [];
-        $drop_image_or_text = "text";
+        $drop_image_or_text = 'text';
 
         list($html, $count) = $this->tracking->getHtmlForDataDefinitionStatements(
             $data,
@@ -824,7 +824,7 @@ class TrackingTest extends TestCase
                 ],
             ],
         ];
-        $filter_users = ["*"];
+        $filter_users = ['*'];
         $filter_ts_to = 9999999999;
         $filter_ts_from = 0;
 
diff --git a/test/classes/TransformationsTest.php b/test/classes/TransformationsTest.php
index a00d0f7b10..8b97618934 100644
--- a/test/classes/TransformationsTest.php
+++ b/test/classes/TransformationsTest.php
@@ -79,7 +79,7 @@ class TransformationsTest extends TestCase
     {
         return [
             [
-                "option1 , option2 ",
+                'option1 , option2 ',
                 [
                     'option1 ',
                     ' option2 ',
@@ -212,8 +212,8 @@ class TransformationsTest extends TestCase
     {
         $_SESSION['relation'][$GLOBALS['server']]['PMA_VERSION'] = PMA_VERSION;
         $_SESSION['relation'][$GLOBALS['server']]['mimework'] = true;
-        $_SESSION['relation'][$GLOBALS['server']]['db'] = "pmadb";
-        $_SESSION['relation'][$GLOBALS['server']]['column_info'] = "column_info";
+        $_SESSION['relation'][$GLOBALS['server']]['db'] = 'pmadb';
+        $_SESSION['relation'][$GLOBALS['server']]['column_info'] = 'column_info';
         $_SESSION['relation'][$GLOBALS['server']]['trackingwork'] = false;
         $this->assertEquals(
             [
@@ -262,8 +262,8 @@ class TransformationsTest extends TestCase
         );
 
         $_SESSION['relation'][$GLOBALS['server']]['PMA_VERSION'] = PMA_VERSION;
-        $_SESSION['relation'][$GLOBALS['server']]['column_info'] = "column_info";
-        $_SESSION['relation'][$GLOBALS['server']]['db'] = "pmadb";
+        $_SESSION['relation'][$GLOBALS['server']]['column_info'] = 'column_info';
+        $_SESSION['relation'][$GLOBALS['server']]['db'] = 'pmadb';
 
         // Case 2 : database delete
         $actual = $this->transformations->clear('db');
diff --git a/test/classes/UserPreferencesTest.php b/test/classes/UserPreferencesTest.php
index 0309fc40b3..922b9bae68 100644
--- a/test/classes/UserPreferencesTest.php
+++ b/test/classes/UserPreferencesTest.php
@@ -109,8 +109,8 @@ class UserPreferencesTest extends PmaTestCase
         // case 2
         $_SESSION['relation'][$GLOBALS['server']]['userconfigwork'] = 1;
         $_SESSION['relation'][$GLOBALS['server']]['db'] = "pma'db";
-        $_SESSION['relation'][$GLOBALS['server']]['userconfig'] = "testconf";
-        $_SESSION['relation'][$GLOBALS['server']]['user'] = "user";
+        $_SESSION['relation'][$GLOBALS['server']]['userconfig'] = 'testconf';
+        $_SESSION['relation'][$GLOBALS['server']]['user'] = 'user';
 
         $dbi = $this->getMockBuilder('PhpMyAdmin\DatabaseInterface')
             ->disableOriginalConstructor()
@@ -199,9 +199,9 @@ class UserPreferencesTest extends PmaTestCase
 
         // case 2
         $_SESSION['relation'][$GLOBALS['server']]['userconfigwork'] = 1;
-        $_SESSION['relation'][$GLOBALS['server']]['db'] = "pmadb";
-        $_SESSION['relation'][$GLOBALS['server']]['userconfig'] = "testconf";
-        $_SESSION['relation'][$GLOBALS['server']]['user'] = "user";
+        $_SESSION['relation'][$GLOBALS['server']]['db'] = 'pmadb';
+        $_SESSION['relation'][$GLOBALS['server']]['userconfig'] = 'testconf';
+        $_SESSION['relation'][$GLOBALS['server']]['user'] = 'user';
 
         $query1 = 'SELECT `username` FROM `pmadb`.`testconf` '
             . 'WHERE `username` = \'user\'';
@@ -257,7 +257,7 @@ class UserPreferencesTest extends PmaTestCase
         $dbi->expects($this->once())
             ->method('getError')
             ->with(DatabaseInterface::CONNECT_CONTROL)
-            ->will($this->returnValue("err1"));
+            ->will($this->returnValue('err1'));
         $dbi->expects($this->any())
             ->method('escapeString')
             ->will($this->returnArgument(0));
@@ -336,7 +336,7 @@ class UserPreferencesTest extends PmaTestCase
         $_SESSION['relation'][$GLOBALS['server']]['PMA_VERSION'] = PMA_VERSION;
         $_SESSION['relation'][$GLOBALS['server']]['userconfigwork'] = null;
         $_SESSION['userconfig'] = [];
-        $_SESSION['userconfig']['ts'] = "123";
+        $_SESSION['userconfig']['ts'] = '123';
         $_SESSION['userconfig']['db'] = [
             'Server/hide_db' => true,
             'Server/only_db' => true,
diff --git a/test/classes/UtilTest.php b/test/classes/UtilTest.php
index badbd4903e..6535f2e3a1 100644
--- a/test/classes/UtilTest.php
+++ b/test/classes/UtilTest.php
@@ -32,8 +32,8 @@ class UtilTest extends PmaTestCase
     public function testCreateGISDataOldMysql(): void
     {
         $this->assertEquals(
-            "abc",
-            Util::createGISData("abc", 50500)
+            'abc',
+            Util::createGISData('abc', 50500)
         );
         $this->assertEquals(
             "GeomFromText('POINT()',10)",
@@ -49,8 +49,8 @@ class UtilTest extends PmaTestCase
     public function testCreateGISDataNewMysql(): void
     {
         $this->assertEquals(
-            "abc",
-            Util::createGISData("abc", 50600)
+            'abc',
+            Util::createGISData('abc', 50600)
         );
         $this->assertEquals(
             "ST_GeomFromText('POINT()',10)",
@@ -89,7 +89,7 @@ class UtilTest extends PmaTestCase
     {
         $this->assertStringContainsString(
             '<select class="pageselector ajax" name="pma" >',
-            Util::pageselector("pma", 3)
+            Util::pageselector('pma', 3)
         );
     }
 
@@ -148,16 +148,16 @@ class UtilTest extends PmaTestCase
     {
         return [
             [
-                "a_b_c_d",
-                " CHARSET=a COLLATE a_b_c_d",
+                'a_b_c_d',
+                ' CHARSET=a COLLATE a_b_c_d',
             ],
             [
-                "a_",
-                " CHARSET=a COLLATE a_",
+                'a_',
+                ' CHARSET=a COLLATE a_',
             ],
             [
-                "a",
-                " CHARSET=a",
+                'a',
+                ' CHARSET=a',
             ],
         ];
     }
@@ -294,7 +294,7 @@ class UtilTest extends PmaTestCase
         $GLOBALS['cfg']['ServerDefault'] = 1;
         $GLOBALS['cfg']['AllowThirdPartyFraming'] = false;
 
-        $this->expectOutputRegex("/Missing parameter: field/");
+        $this->expectOutputRegex('/Missing parameter: field/');
 
         Util::checkParameters(
             [
@@ -319,12 +319,12 @@ class UtilTest extends PmaTestCase
         $GLOBALS['text_dir'] = 'ltr';
         $GLOBALS['PMA_PHP_SELF'] = Core::getenv('PHP_SELF');
         $GLOBALS['pmaThemePath'] = $GLOBALS['PMA_Theme']->getPath();
-        $GLOBALS['db'] = "dbDatabase";
-        $GLOBALS['table'] = "tblTable";
-        $GLOBALS['field'] = "test_field";
-        $GLOBALS['sql_query'] = "SELECT * FROM tblTable;";
+        $GLOBALS['db'] = 'dbDatabase';
+        $GLOBALS['table'] = 'tblTable';
+        $GLOBALS['field'] = 'test_field';
+        $GLOBALS['sql_query'] = 'SELECT * FROM tblTable;';
 
-        $this->expectOutputString("");
+        $this->expectOutputString('');
         Util::checkParameters(
             [
                 'db',
@@ -364,15 +364,15 @@ class UtilTest extends PmaTestCase
         return [
             [
                 "b'",
-                "",
+                '',
             ],
             [
                 "b'01'",
-                "01",
+                '01',
             ],
             [
                 "b'010111010'",
-                "010111010",
+                '010111010',
             ],
         ];
     }
@@ -636,7 +636,7 @@ class UtilTest extends PmaTestCase
                 ],
             ],
             [
-                "INT UNSIGNED zerofill",
+                'INT UNSIGNED zerofill',
                 [
                     'type' => 'int',
                     'print_type' => 'int',
@@ -647,11 +647,11 @@ class UtilTest extends PmaTestCase
                     'enum_set_values' => [],
                     'attribute' => 'UNSIGNED ZEROFILL',
                     'can_contain_collation' => false,
-                    'displayed_type' => "int",
+                    'displayed_type' => 'int',
                 ],
             ],
             [
-                "VARCHAR(255)",
+                'VARCHAR(255)',
                 [
                     'type' => 'varchar',
                     'print_type' => 'varchar(255)',
@@ -662,11 +662,11 @@ class UtilTest extends PmaTestCase
                     'enum_set_values' => [],
                     'attribute' => ' ',
                     'can_contain_collation' => true,
-                    'displayed_type' => "varchar(255)",
+                    'displayed_type' => 'varchar(255)',
                 ],
             ],
             [
-                "VARBINARY(255)",
+                'VARBINARY(255)',
                 [
                     'type' => 'varbinary',
                     'print_type' => 'varbinary(255)',
@@ -677,7 +677,7 @@ class UtilTest extends PmaTestCase
                     'enum_set_values' => [],
                     'attribute' => ' ',
                     'can_contain_collation' => false,
-                    'displayed_type' => "varbinary(255)",
+                    'displayed_type' => 'varbinary(255)',
                 ],
             ],
         ];
@@ -715,15 +715,15 @@ class UtilTest extends PmaTestCase
                 -1,
             ],
             [
-                "10GB",
+                '10GB',
                 10737418240,
             ],
             [
-                "15MB",
+                '15MB',
                 15728640,
             ],
             [
-                "256K",
+                '256K',
                 262144,
             ],
         ];
@@ -1084,7 +1084,7 @@ class UtilTest extends PmaTestCase
     public function testGetFormattedMaximumUploadSize($size, $unit, $res): void
     {
         $this->assertEquals(
-            "(" . __('Max: ') . $res . $unit . ")",
+            '(' . __('Max: ') . $res . $unit . ')',
             Util::getFormattedMaximumUploadSize($size)
         );
     }
@@ -1100,37 +1100,37 @@ class UtilTest extends PmaTestCase
             [
                 10,
                 __('B'),
-                "10",
+                '10',
             ],
             [
                 100,
                 __('B'),
-                "100",
+                '100',
             ],
             [
                 1024,
                 __('B'),
-                "1,024",
+                '1,024',
             ],
             [
                 102400,
                 __('KiB'),
-                "100",
+                '100',
             ],
             [
                 10240000,
                 __('MiB'),
-                "10",
+                '10',
             ],
             [
                 2147483648,
                 __('MiB'),
-                "2,048",
+                '2,048',
             ],
             [
                 21474836480,
                 __('GiB'),
-                "20",
+                '20',
             ],
         ];
     }
@@ -1555,7 +1555,7 @@ class UtilTest extends PmaTestCase
         foreach (Context::$KEYWORDS as $keyword => $type) {
             if ($type & Token::FLAG_KEYWORD_RESERVED) {
                 $this->assertEquals(
-                    "`" . $keyword . "`",
+                    '`' . $keyword . '`',
                     Util::backquote($keyword, false)
                 );
             } else {
@@ -1595,11 +1595,11 @@ class UtilTest extends PmaTestCase
         return [
             [
                 '/var/pma_tmp/%u/',
-                "/var/pma_tmp/root/",
+                '/var/pma_tmp/root/',
             ],
             [
                 '/home/%u/pma',
-                "/home/root/pma/",
+                '/home/root/pma/',
             ],
         ];
     }
diff --git a/test/classes/Utils/HttpRequestTest.php b/test/classes/Utils/HttpRequestTest.php
index 3c24dccb57..7627544466 100644
--- a/test/classes/Utils/HttpRequestTest.php
+++ b/test/classes/Utils/HttpRequestTest.php
@@ -242,32 +242,32 @@ class HttpRequestTest extends PmaTestCase
     {
         return [
             [
-                "https://www.phpmyadmin.net/test/data",
-                "GET",
+                'https://www.phpmyadmin.net/test/data',
+                'GET',
                 true,
                 true,
             ],
             [
-                "https://www.phpmyadmin.net/test/data",
-                "POST",
+                'https://www.phpmyadmin.net/test/data',
+                'POST',
                 true,
                 null,
             ],
             [
-                "https://nonexisting.phpmyadmin.net/test/data",
-                "GET",
+                'https://nonexisting.phpmyadmin.net/test/data',
+                'GET',
                 true,
                 null,
             ],
             [
-                "https://www.phpmyadmin.net/test/data",
-                "GET",
+                'https://www.phpmyadmin.net/test/data',
+                'GET',
                 false,
-                "TEST DATA",
+                'TEST DATA',
             ],
             [
-                "https://www.phpmyadmin.net/test/nothing",
-                "GET",
+                'https://www.phpmyadmin.net/test/nothing',
+                'GET',
                 true,
                 false,
             ],
diff --git a/test/classes/VersionInformationTest.php b/test/classes/VersionInformationTest.php
index 2782605e2f..6180faf57f 100644
--- a/test/classes/VersionInformationTest.php
+++ b/test/classes/VersionInformationTest.php
@@ -32,24 +32,24 @@ class VersionInformationTest extends PmaTestCase
         $this->_releases = [];
 
         $release = new stdClass();
-        $release->date = "2015-09-08";
-        $release->php_versions = ">=5.3,<7.1";
-        $release->version = "4.4.14.1";
-        $release->mysql_versions = ">=5.5";
+        $release->date = '2015-09-08';
+        $release->php_versions = '>=5.3,<7.1';
+        $release->version = '4.4.14.1';
+        $release->mysql_versions = '>=5.5';
         $this->_releases[] = $release;
 
         $release = new stdClass();
-        $release->date = "2015-09-09";
-        $release->php_versions = ">=5.3,<7.0";
-        $release->version = "4.4.13.3";
-        $release->mysql_versions = ">=5.5";
+        $release->date = '2015-09-09';
+        $release->php_versions = '>=5.3,<7.0';
+        $release->version = '4.4.13.3';
+        $release->mysql_versions = '>=5.5';
         $this->_releases[] = $release;
 
         $release = new stdClass();
-        $release->date = "2015-05-13";
-        $release->php_versions = ">=5.2,<5.3";
-        $release->version = "4.0.10.10";
-        $release->mysql_versions = ">=5.0";
+        $release->date = '2015-05-13';
+        $release->php_versions = '>=5.2,<5.3';
+        $release->version = '4.0.10.10';
+        $release->mysql_versions = '>=5.0';
         $this->_releases[] = $release;
     }
 
diff --git a/test/classes/ZipExtensionTest.php b/test/classes/ZipExtensionTest.php
index ab4f698179..c11dc72edd 100644
--- a/test/classes/ZipExtensionTest.php
+++ b/test/classes/ZipExtensionTest.php
@@ -154,7 +154,7 @@ class ZipExtensionTest extends PmaTestCase
      */
     public function testCreateSingleFile()
     {
-        $file = $this->zipExtension->createFile("Test content", "test.txt");
+        $file = $this->zipExtension->createFile('Test content', 'test.txt');
         $this->assertNotEmpty($file);
 
         $tmp = tempnam('./', 'zip-test');
@@ -183,10 +183,10 @@ class ZipExtensionTest extends PmaTestCase
         $this->assertEquals(
             false,
             $this->zipExtension->createFile(
-                "Content",
+                'Content',
                 [
-                    "name1.txt",
-                    "name2.txt",
+                    'name1.txt',
+                    'name2.txt',
                 ]
             )
         );
@@ -201,12 +201,12 @@ class ZipExtensionTest extends PmaTestCase
     {
         $file = $this->zipExtension->createFile(
             [
-                "Content",
+                'Content',
                 'Content2',
             ],
             [
-                "name1.txt",
-                "name2.txt",
+                'name1.txt',
+                'name2.txt',
             ]
         );
         $this->assertNotEmpty($file);
diff --git a/test/selenium/ChangePasswordTest.php b/test/selenium/ChangePasswordTest.php
index 44493dada4..12f986d726 100644
--- a/test/selenium/ChangePasswordTest.php
+++ b/test/selenium/ChangePasswordTest.php
@@ -38,50 +38,50 @@ class ChangePasswordTest extends TestBase
     {
         $this->login();
 
-        $e = $this->waitForElement('id', "change_password_anchor");
+        $e = $this->waitForElement('id', 'change_password_anchor');
         $e->click();
 
         $this->waitAjax();
 
         $this->waitForElement('xpath', "//span[contains(., 'Change password')]");
         try {
-            $ele = $this->waitForElement('name', "pma_pw");
-            $this->assertEquals("", $ele->getAttribute('value'));
+            $ele = $this->waitForElement('name', 'pma_pw');
+            $this->assertEquals('', $ele->getAttribute('value'));
         } catch (AssertionFailedError $e) {
             array_push($this->verificationErrors, $e->toString());
         }
         try {
-            $ele = $this->waitForElement('name', "pma_pw2");
-            $this->assertEquals("", $ele->getAttribute('value'));
+            $ele = $this->waitForElement('name', 'pma_pw2');
+            $this->assertEquals('', $ele->getAttribute('value'));
         } catch (AssertionFailedError $e) {
             array_push($this->verificationErrors, $e->toString());
         }
         try {
-            $ele = $this->waitForElement('name', "generated_pw");
-            $this->assertEquals("", $ele->getAttribute('value'));
+            $ele = $this->waitForElement('name', 'generated_pw');
+            $this->assertEquals('', $ele->getAttribute('value'));
         } catch (AssertionFailedError $e) {
             array_push($this->verificationErrors, $e->toString());
         }
-        $this->byId("button_generate_password")->click();
-        $this->assertNotEquals("", $this->byName("pma_pw")->getAttribute('value'));
-        $this->assertNotEquals("", $this->byName("pma_pw2")->getAttribute('value'));
-        $this->assertNotEquals("", $this->byName("generated_pw")->getAttribute('value'));
+        $this->byId('button_generate_password')->click();
+        $this->assertNotEquals('', $this->byName('pma_pw')->getAttribute('value'));
+        $this->assertNotEquals('', $this->byName('pma_pw2')->getAttribute('value'));
+        $this->assertNotEquals('', $this->byName('generated_pw')->getAttribute('value'));
 
-        if ($GLOBALS['TESTSUITE_PASSWORD'] != "") {
-            $this->byName("pma_pw")->clear();
-            $this->byName("pma_pw2")->clear();
+        if ($GLOBALS['TESTSUITE_PASSWORD'] != '') {
+            $this->byName('pma_pw')->clear();
+            $this->byName('pma_pw2')->clear();
 
             $this->byName('pma_pw')->click()->sendKeys($GLOBALS['TESTSUITE_PASSWORD']);
 
             $this->byName('pma_pw2')->click()->sendKeys($GLOBALS['TESTSUITE_PASSWORD']);
         } else {
-            $this->byId("nopass_1")->click();
+            $this->byId('nopass_1')->click();
         }
 
         $this->byXpath("//button[contains(., 'Go')]")->click();
-        $ele = $this->waitForElement('cssSelector', ".alert-success");
+        $ele = $this->waitForElement('cssSelector', '.alert-success');
         $this->assertEquals(
-            "The profile has been updated.",
+            'The profile has been updated.',
             trim($ele->getText())
         );
     }
diff --git a/test/selenium/CreateDropDatabaseTest.php b/test/selenium/CreateDropDatabaseTest.php
index 83cbb3e7f0..db2494e4b6 100644
--- a/test/selenium/CreateDropDatabaseTest.php
+++ b/test/selenium/CreateDropDatabaseTest.php
@@ -52,7 +52,7 @@ class CreateDropDatabaseTest extends TestBase
         $element->clear();
         $element->sendKeys($this->database_name);
 
-        $this->byId("buttonGo")->click();
+        $this->byId('buttonGo')->click();
 
         $element = $this->waitForElement('linkText', 'Database: ' . $this->database_name);
 
@@ -81,8 +81,8 @@ class CreateDropDatabaseTest extends TestBase
             "input[name='selected_dbs[]'][value='" . $this->database_name . "']"
         )->click();
 
-        $this->byCssSelector("button.mult_submit")->click();
-        $this->byCssSelector("button.submitOK")->click();
+        $this->byCssSelector('button.mult_submit')->click();
+        $this->byCssSelector('button.submitOK')->click();
 
         $this->waitForElementNotPresent(
             'cssSelector',
@@ -91,7 +91,7 @@ class CreateDropDatabaseTest extends TestBase
 
         $this->waitForElement(
             'cssSelector',
-            "span.ajax_notification .alert-success"
+            'span.ajax_notification .alert-success'
         );
 
         $result = $this->dbQuery(
diff --git a/test/selenium/CreateRemoveUserTest.php b/test/selenium/CreateRemoveUserTest.php
index 55f49d1d2b..e62506d7f4 100644
--- a/test/selenium/CreateRemoveUserTest.php
+++ b/test/selenium/CreateRemoveUserTest.php
@@ -57,33 +57,33 @@ class CreateRemoveUserTest extends TestBase
      */
     public function testCreateRemoveUser()
     {
-        $this->waitForElement('partialLinkText', "User accounts")->click();
+        $this->waitForElement('partialLinkText', 'User accounts')->click();
 
         // Let the User Accounts page load
         $this->waitAjax();
 
         $this->scrollIntoView('add_user_anchor');
         $this->waitForElement('id', 'usersForm');
-        $ele = $this->waitForElement('id', "add_user_anchor");
+        $ele = $this->waitForElement('id', 'add_user_anchor');
         $this->moveto($ele);
         $ele->click();
 
         $this->waitAjax();
-        $userField = $this->waitForElement('name', "username");
+        $userField = $this->waitForElement('name', 'username');
         $userField->sendKeys($this->_txtUsername);
 
-        $this->selectByLabel($this->byId("select_pred_hostname"), 'Local');
+        $this->selectByLabel($this->byId('select_pred_hostname'), 'Local');
 
         $this->scrollIntoView('button_generate_password');
         $genButton = $this->waitForElement('id', 'button_generate_password');
         $genButton->click();
 
-        $this->assertNotEquals("", $this->byId("text_pma_pw")->getAttribute('value'));
-        $this->assertNotEquals("", $this->byId("text_pma_pw2")->getAttribute('value'));
-        $this->assertNotEquals("", $this->byId("generated_pw")->getAttribute('value'));
+        $this->assertNotEquals('', $this->byId('text_pma_pw')->getAttribute('value'));
+        $this->assertNotEquals('', $this->byId('text_pma_pw2')->getAttribute('value'));
+        $this->assertNotEquals('', $this->byId('generated_pw')->getAttribute('value'));
 
-        $this->byId("text_pma_pw")->sendKeys($this->_txtPassword);
-        $this->byId("text_pma_pw2")->sendKeys($this->_txtPassword);
+        $this->byId('text_pma_pw')->sendKeys($this->_txtPassword);
+        $this->byId('text_pma_pw2')->sendKeys($this->_txtPassword);
 
         // Make sure the element is visible before clicking
         $this->scrollIntoView('createdb-1');
@@ -91,31 +91,31 @@ class CreateRemoveUserTest extends TestBase
         $this->waitForElement('id', 'createdb-2')->click();
 
         $this->scrollIntoView('addUsersForm_checkall');
-        $this->byId("addUsersForm_checkall")->click();
+        $this->byId('addUsersForm_checkall')->click();
 
         $this->scrollIntoView('adduser_submit');
-        $this->waitForElement('id', "adduser_submit")->click();
+        $this->waitForElement('id', 'adduser_submit')->click();
 
-        $success = $this->waitForElement('cssSelector', ".alert-success");
+        $success = $this->waitForElement('cssSelector', '.alert-success');
         $this->assertStringContainsString('You have added a new user', $success->getText());
 
         // Removing the newly added user
-        $this->waitForElement('partialLinkText', "User accounts")->click();
-        $el = $this->waitForElement('id', "usersForm");
-        $temp = $this->_txtUsername . "&amp;#27;localhost";
+        $this->waitForElement('partialLinkText', 'User accounts')->click();
+        $el = $this->waitForElement('id', 'usersForm');
+        $temp = $this->_txtUsername . '&amp;#27;localhost';
 
         $this->byXPath(
             "(//input[@name='selected_usr[]'])[@value='" . $temp . "']"
         )->click();
 
         $this->scrollIntoView('fieldset_delete_user_footer');
-        $this->byId("checkbox_drop_users_db")->click();
+        $this->byId('checkbox_drop_users_db')->click();
 
-        $this->byId("buttonGo")->click();
-        $this->waitForElement('cssSelector', "button.submitOK")->click();
+        $this->byId('buttonGo')->click();
+        $this->waitForElement('cssSelector', 'button.submitOK')->click();
         $this->acceptAlert();
 
-        $success = $this->waitForElement('cssSelector', ".alert-success");
+        $success = $this->waitForElement('cssSelector', '.alert-success');
         $this->assertStringContainsString(
             'The selected users have been deleted',
             $success->getText()
diff --git a/test/selenium/Database/EventsTest.php b/test/selenium/Database/EventsTest.php
index d4e036dd6a..58cabd0122 100644
--- a/test/selenium/Database/EventsTest.php
+++ b/test/selenium/Database/EventsTest.php
@@ -29,17 +29,17 @@ class EventsTest extends TestBase
     {
         parent::setUp();
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "INSERT INTO `test_table` (val) VALUES (2);"
+            'INSERT INTO `test_table` (val) VALUES (2);'
         );
         $this->dbQuery(
-            "SET GLOBAL event_scheduler=\"ON\""
+            'SET GLOBAL event_scheduler="ON"'
         );
         $this->login();
         $this->navigateDatabase($this->database_name);
@@ -57,7 +57,7 @@ class EventsTest extends TestBase
     protected function tearDown(): void
     {
         if (isset($this->_mysqli)) {
-            $this->dbQuery("SET GLOBAL event_scheduler=\"OFF\"");
+            $this->dbQuery('SET GLOBAL event_scheduler="OFF"');
         }
         parent::tearDown();
     }
@@ -73,10 +73,10 @@ class EventsTest extends TestBase
         $end = date('Y-m-d H:i:s', strtotime('+1 day'));
 
         $this->dbQuery(
-            "CREATE EVENT `test_event` ON SCHEDULE EVERY 1 MINUTE_SECOND STARTS "
-            . "'$start' ENDS '$end' ON COMPLETION NOT PRESERVE ENABLE "
-            . "DO UPDATE `" . $this->database_name
-            . "`.`test_table` SET val = val + 1"
+            'CREATE EVENT `test_event` ON SCHEDULE EVERY 1 MINUTE_SECOND STARTS '
+            . "'" . $start . "' ENDS '" . $end . "' ON COMPLETION NOT PRESERVE ENABLE "
+            . 'DO UPDATE `' . $this->database_name
+            . '`.`test_table` SET val = val + 1'
         );
     }
 
@@ -89,29 +89,29 @@ class EventsTest extends TestBase
      */
     public function testAddEvent()
     {
-        $this->waitForElement('partialLinkText', "Events")->click();
+        $this->waitForElement('partialLinkText', 'Events')->click();
         $this->waitAjax();
 
-        $this->waitForElement('partialLinkText', "Add event")->click();
+        $this->waitForElement('partialLinkText', 'Add event')->click();
         $this->waitAjax();
 
-        $this->waitForElement('className', "rte_form");
+        $this->waitForElement('className', 'rte_form');
 
-        $this->selectByLabel($this->byName("item_type"), 'RECURRING');
+        $this->selectByLabel($this->byName('item_type'), 'RECURRING');
 
-        $this->byName("item_name")->sendKeys("test_event");
+        $this->byName('item_name')->sendKeys('test_event');
         $this->selectByLabel(
-            $this->byName("item_interval_field"),
+            $this->byName('item_interval_field'),
             'MINUTE_SECOND'
         );
 
-        $this->byName("item_starts")->click()->clear()->sendKeys(date('Y-m-d', strtotime('-1 day')) . ' 00:00:00');
+        $this->byName('item_starts')->click()->clear()->sendKeys(date('Y-m-d', strtotime('-1 day')) . ' 00:00:00');
 
-        $this->byName("item_ends")->click()->clear()->sendKeys(date('Y-m-d', strtotime('+1 day')) . ' 00:00:00');
+        $this->byName('item_ends')->click()->clear()->sendKeys(date('Y-m-d', strtotime('+1 day')) . ' 00:00:00');
 
-        $this->waitForElement('name', "item_interval_value")->click()->clear()->sendKeys('1');
+        $this->waitForElement('name', 'item_interval_value')->click()->clear()->sendKeys('1');
 
-        $proc = "UPDATE " . $this->database_name . ".`test_table` SET val=val+1";
+        $proc = 'UPDATE ' . $this->database_name . '.`test_table` SET val=val+1';
         $this->typeInTextArea($proc);
 
         $this->byXPath("//button[contains(., 'Go')]")->click();
@@ -144,7 +144,7 @@ class EventsTest extends TestBase
 
         sleep(2);
         $result = $this->dbQuery(
-            "SELECT val FROM `" . $this->database_name . "`.`test_table`"
+            'SELECT val FROM `' . $this->database_name . '`.`test_table`'
         );
         $row = $result->fetch_assoc();
         $this->assertGreaterThan(2, $row['val']);
@@ -160,7 +160,7 @@ class EventsTest extends TestBase
     public function testEditEvents()
     {
         $this->_eventSQL();
-        $this->waitForElement('partialLinkText', "Events")->click();
+        $this->waitForElement('partialLinkText', 'Events')->click();
         $this->waitAjax();
 
         $this->waitForElement(
@@ -168,11 +168,11 @@ class EventsTest extends TestBase
             "//legend[contains(., 'Events')]"
         );
 
-        $this->byPartialLinkText("Edit")->click();
+        $this->byPartialLinkText('Edit')->click();
 
-        $this->waitForElement('className', "rte_form");
-        $this->byName("item_interval_value")->clear();
-        $this->byName("item_interval_value")->sendKeys("2");
+        $this->waitForElement('className', 'rte_form');
+        $this->byName('item_interval_value')->clear();
+        $this->byName('item_interval_value')->sendKeys('2');
 
         $this->byXPath("//button[contains(., 'Go')]")->click();
 
@@ -184,7 +184,7 @@ class EventsTest extends TestBase
 
         sleep(2);
         $result = $this->dbQuery(
-            "SELECT val FROM `" . $this->database_name . "`.`test_table`"
+            'SELECT val FROM `' . $this->database_name . '`.`test_table`'
         );
         $row = $result->fetch_assoc();
         $this->assertGreaterThan(2, $row['val']);
@@ -200,7 +200,7 @@ class EventsTest extends TestBase
     public function testDropEvent()
     {
         $this->_eventSQL();
-        $this->waitForElement('partialLinkText', "Events")->click();
+        $this->waitForElement('partialLinkText', 'Events')->click();
         $this->waitAjax();
 
         $this->waitForElement(
@@ -208,10 +208,10 @@ class EventsTest extends TestBase
             "//legend[contains(., 'Events')]"
         );
 
-        $this->byPartialLinkText("Drop")->click();
+        $this->byPartialLinkText('Drop')->click();
         $this->waitForElement(
             'className',
-            "submitOK"
+            'submitOK'
         )->click();
 
         $this->waitAjaxMessage();
diff --git a/test/selenium/Database/OperationsTest.php b/test/selenium/Database/OperationsTest.php
index 175268b2db..2210612b37 100644
--- a/test/selenium/Database/OperationsTest.php
+++ b/test/selenium/Database/OperationsTest.php
@@ -59,7 +59,7 @@ class OperationsTest extends TestBase
         $this->skipIfNotPMADB();
 
         $this->_getToDBOperations();
-        $this->byName("comment")->sendKeys("comment_foobar");
+        $this->byName('comment')->sendKeys('comment_foobar');
         $this->byCssSelector(
             "form#formDatabaseComment input[type='submit']"
         )->click();
@@ -86,23 +86,23 @@ class OperationsTest extends TestBase
         $new_db_name = $this->database_name . 'rename';
 
         $this->scrollIntoView('create_table_form_minimal');
-        $this->byCssSelector("form#rename_db_form input[name=newname]")
+        $this->byCssSelector('form#rename_db_form input[name=newname]')
             ->sendKeys($new_db_name);
 
         $this->byCssSelector("form#rename_db_form input[type='submit']")->click();
 
         $this->waitForElement(
             'cssSelector',
-            "button.submitOK"
+            'button.submitOK'
         )->click();
 
         $this->waitForElement(
             'xpath',
-            "//a[@class='item' and contains(., 'Database: $new_db_name')]"
+            "//a[@class='item' and contains(., 'Database: " . $new_db_name . "')]"
         );
 
         $result = $this->dbQuery(
-            "SHOW DATABASES LIKE '$new_db_name';"
+            "SHOW DATABASES LIKE '" . $new_db_name . "';"
         );
         $this->assertEquals(1, $result->num_rows);
 
@@ -126,7 +126,7 @@ class OperationsTest extends TestBase
         $this->_getToDBOperations();
 
         $new_db_name = $this->database_name . 'copy';
-        $this->byCssSelector("form#copy_db_form input[name=newname]")
+        $this->byCssSelector('form#copy_db_form input[name=newname]')
             ->sendKeys($new_db_name);
 
         $this->scrollIntoView('copy_db_form', -150);
@@ -136,14 +136,14 @@ class OperationsTest extends TestBase
             'xpath',
             "//div[@class='alert alert-success' and contains(., 'Database "
             . $this->database_name
-            . " has been copied to $new_db_name')]"
+            . ' has been copied to ' . $new_db_name . "')]"
         );
 
         $result = $this->dbQuery(
-            "SHOW DATABASES LIKE '$new_db_name';"
+            "SHOW DATABASES LIKE '" . $new_db_name . "';"
         );
         $this->assertEquals(1, $result->num_rows);
 
-        $this->dbQuery("DROP DATABASE $new_db_name");
+        $this->dbQuery('DROP DATABASE ' . $new_db_name);
     }
 }
diff --git a/test/selenium/Database/ProceduresTest.php b/test/selenium/Database/ProceduresTest.php
index 508be2a30f..dd83f730e6 100644
--- a/test/selenium/Database/ProceduresTest.php
+++ b/test/selenium/Database/ProceduresTest.php
@@ -36,7 +36,7 @@ class ProceduresTest extends TestBase
     {
         parent::setUp();
         if ($this->originalSqlMode === -1) {
-            $this->originalSqlMode = $this->dbQuery('SELECT @@GLOBAL.SQL_MODE as globalsqm;')->fetch_all(MYSQLI_ASSOC)[0]["globalsqm"];
+            $this->originalSqlMode = $this->dbQuery('SELECT @@GLOBAL.SQL_MODE as globalsqm;')->fetch_all(MYSQLI_ASSOC)[0]['globalsqm'];
             $this->dbQuery(
                 "SET GLOBAL sql_mode = '" .
                 str_replace(
@@ -48,12 +48,12 @@ class ProceduresTest extends TestBase
         }
 
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `name` varchar(20) NOT NULL,"
-            . " `datetimefield` datetime NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `name` varchar(20) NOT NULL,'
+            . ' `datetimefield` datetime NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
 
         $this->login();
@@ -72,7 +72,7 @@ class ProceduresTest extends TestBase
         $this->dbQuery(
             "SET GLOBAL sql_mode = '" . $this->originalSqlMode . "';"
         );
-        $this->assertEquals($this->originalSqlMode, $this->dbQuery('SELECT @@GLOBAL.SQL_MODE as globalsqm;')->fetch_all(MYSQLI_ASSOC)[0]["globalsqm"]);
+        $this->assertEquals($this->originalSqlMode, $this->dbQuery('SELECT @@GLOBAL.SQL_MODE as globalsqm;')->fetch_all(MYSQLI_ASSOC)[0]['globalsqm']);
         parent::tearDown();
     }
 
@@ -84,9 +84,9 @@ class ProceduresTest extends TestBase
     private function _procedureSQL()
     {
         $this->dbQuery(
-            "CREATE PROCEDURE `test_procedure`(IN `inp` VARCHAR(20), OUT `outp` INT)"
-            . " NOT DETERMINISTIC READS SQL DATA SQL SECURITY DEFINER SELECT char_"
-            . "length(inp) + count(*) FROM test_table INTO outp"
+            'CREATE PROCEDURE `test_procedure`(IN `inp` VARCHAR(20), OUT `outp` INT)'
+            . ' NOT DETERMINISTIC READS SQL DATA SQL SECURITY DEFINER SELECT char_'
+            . 'length(inp) + count(*) FROM test_table INTO outp'
         );
     }
 
@@ -99,36 +99,36 @@ class ProceduresTest extends TestBase
      */
     public function testAddProcedure()
     {
-        $this->waitForElement('partialLinkText', "Routines")->click();
+        $this->waitForElement('partialLinkText', 'Routines')->click();
         $this->waitAjax();
 
-        $this->waitForElement('partialLinkText', "Add routine")->click();
+        $this->waitForElement('partialLinkText', 'Add routine')->click();
 
-        $this->waitForElement('className', "rte_form");
+        $this->waitForElement('className', 'rte_form');
 
-        $this->byName("item_name")->sendKeys("test_procedure");
+        $this->byName('item_name')->sendKeys('test_procedure');
 
-        $this->byName("item_param_name[0]")->sendKeys("inp");
+        $this->byName('item_param_name[0]')->sendKeys('inp');
         $this->selectByLabel(
-            $this->byName("item_param_type[0]"),
+            $this->byName('item_param_type[0]'),
             'VARCHAR'
         );
-        $this->byName("item_param_length[0]")->sendKeys("20");
+        $this->byName('item_param_length[0]')->sendKeys('20');
 
         $this->byCssSelector("input[value='Add parameter']")->click();
 
         $this->selectByLabel(
-            $this->byName("item_param_dir[1]"),
+            $this->byName('item_param_dir[1]'),
             'OUT'
         );
-        $ele = $this->waitForElement('name', "item_param_name[1]");
-        $ele->sendKeys("outp");
+        $ele = $this->waitForElement('name', 'item_param_name[1]');
+        $ele->sendKeys('outp');
 
-        $proc = "SELECT char_length(inp) + count(*) FROM test_table INTO outp";
+        $proc = 'SELECT char_length(inp) + count(*) FROM test_table INTO outp';
         $this->typeInTextArea($proc);
 
         $this->selectByLabel(
-            $this->byName("item_sqldataaccess"),
+            $this->byName('item_sqldataaccess'),
             'READS SQL DATA'
         );
 
@@ -145,7 +145,7 @@ class ProceduresTest extends TestBase
         );
 
         $this->assertEquals(1, $result->num_rows);
-        $this->_executeProcedure("test_procedure", 14);
+        $this->_executeProcedure('test_procedure', 14);
     }
 
     /**
@@ -158,7 +158,7 @@ class ProceduresTest extends TestBase
     public function testEditProcedure()
     {
         $this->_procedureSQL();
-        $this->waitForElement('partialLinkText', "Routines")->click();
+        $this->waitForElement('partialLinkText', 'Routines')->click();
         $this->waitAjax();
 
         $this->waitForElement(
@@ -166,10 +166,10 @@ class ProceduresTest extends TestBase
             "//legend[contains(., 'Routines')]"
         );
 
-        $this->byPartialLinkText("Edit")->click();
-        $this->waitForElement('className', "rte_form");
-        $this->byName("item_param_length[0]")->clear();
-        $this->byName("item_param_length[0]")->sendKeys("30");
+        $this->byPartialLinkText('Edit')->click();
+        $this->waitForElement('className', 'rte_form');
+        $this->byName('item_param_length[0]')->clear();
+        $this->byName('item_param_length[0]')->sendKeys('30');
 
         $this->byXPath("//button[contains(., 'Go')]")->click();
 
@@ -179,7 +179,7 @@ class ProceduresTest extends TestBase
             . "'Routine `test_procedure` has been modified')]"
         );
 
-        $this->_executeProcedure("test_procedure", 14);
+        $this->_executeProcedure('test_procedure', 14);
     }
 
     /**
@@ -192,7 +192,7 @@ class ProceduresTest extends TestBase
     public function testDropProcedure()
     {
         $this->_procedureSQL();
-        $this->waitForElement('partialLinkText', "Routines")->click();
+        $this->waitForElement('partialLinkText', 'Routines')->click();
         $this->waitAjax();
 
         $this->waitForElement(
@@ -200,10 +200,10 @@ class ProceduresTest extends TestBase
             "//legend[contains(., 'Routines')]"
         );
 
-        $this->byPartialLinkText("Drop")->click();
+        $this->byPartialLinkText('Drop')->click();
         $this->waitForElement(
             'cssSelector',
-            "button.submitOK"
+            'button.submitOK'
         )->click();
 
         $this->waitAjaxMessage();
@@ -226,15 +226,15 @@ class ProceduresTest extends TestBase
     {
         $this->waitAjax();
         $this->waitUntilElementIsVisible('linkText', ' Execute', 30)->click();// The space before Execute is because of &nbsp;
-        $this->waitUntilElementIsVisible('name', "params[inp]", 30)->sendKeys($text);
-        $this->byCssSelector("div.ui-dialog-buttonset button:nth-child(1)")->click();
+        $this->waitUntilElementIsVisible('name', 'params[inp]', 30)->sendKeys($text);
+        $this->byCssSelector('div.ui-dialog-buttonset button:nth-child(1)')->click();
 
         $this->waitAjax();
         $this->waitForElement(
             'cssSelector',
-            "span#PMA_slidingMessage table tbody"
+            'span#PMA_slidingMessage table tbody'
         );
-        $head = $this->byCssSelector("span#PMA_slidingMessage table tbody")->getText();
-        $this->assertEquals("outp\n$length", $head);
+        $head = $this->byCssSelector('span#PMA_slidingMessage table tbody')->getText();
+        $this->assertEquals("outp\n" . $length, $head);
     }
 }
diff --git a/test/selenium/Database/QueryByExampleTest.php b/test/selenium/Database/QueryByExampleTest.php
index a1e239b8ae..4682f24657 100644
--- a/test/selenium/Database/QueryByExampleTest.php
+++ b/test/selenium/Database/QueryByExampleTest.php
@@ -30,14 +30,14 @@ class QueryByExampleTest extends TestBase
         parent::setUp();
 
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "INSERT INTO `test_table` (val) VALUES (2), (6), (5), (3), (4), (4), (5);"
+            'INSERT INTO `test_table` (val) VALUES (2), (6), (5), (3), (4), (4), (5);'
         );
 
         $this->login();
@@ -118,7 +118,7 @@ class QueryByExampleTest extends TestBase
 
         $this->scrollToBottom();
 
-        $expected = "SELECT `test_table`.`id` AS `ID`, `test_table`.`val` AS `VAL`"
+        $expected = 'SELECT `test_table`.`id` AS `ID`, `test_table`.`val` AS `VAL`'
             . "\nFROM `test_table`"
             . "\nWHERE ((`test_table`.`id` > 1) AND (`test_table`.`val` < 6))"
             . "\nORDER BY `test_table`.`val` ASC, `test_table`.`id` DESC";
diff --git a/test/selenium/Database/StructureTest.php b/test/selenium/Database/StructureTest.php
index 5d0d47239e..d1dd90a740 100644
--- a/test/selenium/Database/StructureTest.php
+++ b/test/selenium/Database/StructureTest.php
@@ -29,21 +29,21 @@ class StructureTest extends TestBase
     {
         parent::setUp();
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "CREATE TABLE `test_table2` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table2` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "INSERT INTO `test_table` (val) VALUES (2);"
+            'INSERT INTO `test_table` (val) VALUES (2);'
         );
 
         $this->login();
@@ -67,7 +67,7 @@ class StructureTest extends TestBase
 
         $this->waitForElement(
             'cssSelector',
-            "button.submitOK"
+            'button.submitOK'
         )->click();
 
         $this->assertNotNull(
@@ -78,7 +78,7 @@ class StructureTest extends TestBase
             )
         );
 
-        $result = $this->dbQuery("SELECT count(*) as c FROM test_table");
+        $result = $this->dbQuery('SELECT count(*) as c FROM test_table');
         $row = $result->fetch_assoc();
         $this->assertEquals(0, $row['c']);
     }
@@ -95,11 +95,11 @@ class StructureTest extends TestBase
         $this->byCssSelector("label[for='tablesForm_checkall']")->click();
 
         $this->selectByLabel(
-            $this->byName("submit_mult"),
+            $this->byName('submit_mult'),
             'Drop'
         );
 
-        $this->waitForElement('id', "buttonYes")
+        $this->waitForElement('id', 'buttonYes')
             ->click();
 
         $this->waitForElement(
@@ -107,7 +107,7 @@ class StructureTest extends TestBase
             "//*[contains(., 'No tables found in database')]"
         );
 
-        $result = $this->dbQuery("SHOW TABLES;");
+        $result = $this->dbQuery('SHOW TABLES;');
         $this->assertEquals(0, $result->num_rows);
     }
 }
diff --git a/test/selenium/Database/TriggersTest.php b/test/selenium/Database/TriggersTest.php
index 011cfada3e..ea9341b7e4 100644
--- a/test/selenium/Database/TriggersTest.php
+++ b/test/selenium/Database/TriggersTest.php
@@ -29,22 +29,22 @@ class TriggersTest extends TestBase
     {
         parent::setUp();
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
 
         $this->dbQuery(
-            "CREATE TABLE `test_table2` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table2` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "INSERT INTO `test_table2` (val) VALUES (2);"
+            'INSERT INTO `test_table2` (val) VALUES (2);'
         );
 
         $this->login();
@@ -60,10 +60,10 @@ class TriggersTest extends TestBase
     private function _triggerSQL()
     {
         $this->dbQuery(
-            "CREATE TRIGGER `test_trigger` "
-            . "AFTER INSERT ON `test_table` FOR EACH ROW"
-            . " UPDATE `" . $this->database_name
-            . "`.`test_table2` SET val = val + 1"
+            'CREATE TRIGGER `test_trigger` '
+            . 'AFTER INSERT ON `test_table` FOR EACH ROW'
+            . ' UPDATE `' . $this->database_name
+            . '`.`test_table2` SET val = val + 1'
         );
     }
 
@@ -77,32 +77,32 @@ class TriggersTest extends TestBase
     public function testAddTrigger()
     {
         $this->expandMore();
-        $this->waitForElement('partialLinkText', "Triggers")->click();
+        $this->waitForElement('partialLinkText', 'Triggers')->click();
         $this->waitAjax();
 
-        $this->waitForElement('partialLinkText', "Add trigger")->click();
+        $this->waitForElement('partialLinkText', 'Add trigger')->click();
         $this->waitAjax();
 
-        $this->waitForElement('className', "rte_form");
+        $this->waitForElement('className', 'rte_form');
 
-        $this->byName("item_name")->sendKeys("test_trigger");
+        $this->byName('item_name')->sendKeys('test_trigger');
 
         $this->selectByLabel(
-            $this->byName("item_table"),
+            $this->byName('item_table'),
             'test_table'
         );
 
         $this->selectByLabel(
-            $this->byName("item_timing"),
+            $this->byName('item_timing'),
             'AFTER'
         );
 
         $this->selectByLabel(
-            $this->byName("item_event"),
+            $this->byName('item_event'),
             'INSERT'
         );
 
-        $proc = "UPDATE " . $this->database_name . ".`test_table2` SET val=val+1";
+        $proc = 'UPDATE ' . $this->database_name . '.`test_table2` SET val=val+1';
         $this->typeInTextArea($proc);
 
         $this->byXPath("//button[contains(., 'Go')]")->click();
@@ -121,13 +121,13 @@ class TriggersTest extends TestBase
         );
 
         $result = $this->dbQuery(
-            "SHOW TRIGGERS FROM `" . $this->database_name . "`;"
+            'SHOW TRIGGERS FROM `' . $this->database_name . '`;'
         );
         $this->assertEquals(1, $result->num_rows);
 
         // test trigger
-        $this->dbQuery("INSERT INTO `test_table` (val) VALUES (1);");
-        $result = $this->dbQuery("SELECT val FROM `test_table2`;");
+        $this->dbQuery('INSERT INTO `test_table` (val) VALUES (1);');
+        $result = $this->dbQuery('SELECT val FROM `test_table2`;');
         $row = $result->fetch_assoc();
         $this->assertEquals(3, $row['val']);
     }
@@ -144,7 +144,7 @@ class TriggersTest extends TestBase
         $this->expandMore();
 
         $this->_triggerSQL();
-        $this->waitForElement('partialLinkText', "Triggers")->click();
+        $this->waitForElement('partialLinkText', 'Triggers')->click();
         $this->waitAjax();
 
         $this->waitForElement(
@@ -152,10 +152,10 @@ class TriggersTest extends TestBase
             "//legend[contains(., 'Triggers')]"
         );
 
-        $this->byPartialLinkText("Edit")->click();
+        $this->byPartialLinkText('Edit')->click();
 
-        $this->waitForElement('className', "rte_form");
-        $proc = "UPDATE " . $this->database_name . ".`test_table2` SET val=val+10";
+        $this->waitForElement('className', 'rte_form');
+        $proc = 'UPDATE ' . $this->database_name . '.`test_table2` SET val=val+10';
         $this->typeInTextArea($proc);
 
         $this->byXPath("//button[contains(., 'Go')]")->click();
@@ -167,8 +167,8 @@ class TriggersTest extends TestBase
         );
 
         // test trigger
-        $this->dbQuery("INSERT INTO `test_table` (val) VALUES (1);");
-        $result = $this->dbQuery("SELECT val FROM `test_table2`;");
+        $this->dbQuery('INSERT INTO `test_table` (val) VALUES (1);');
+        $result = $this->dbQuery('SELECT val FROM `test_table2`;');
         $row = $result->fetch_assoc();
         $this->assertEquals(12, $row['val']);
     }
@@ -185,7 +185,7 @@ class TriggersTest extends TestBase
         $this->expandMore();
 
         $this->_triggerSQL();
-        $ele = $this->waitForElement('partialLinkText', "Triggers");
+        $ele = $this->waitForElement('partialLinkText', 'Triggers');
         $ele->click();
 
         $this->waitForElement(
@@ -193,22 +193,22 @@ class TriggersTest extends TestBase
             "//legend[contains(., 'Triggers')]"
         );
 
-        $this->byPartialLinkText("Drop")->click();
+        $this->byPartialLinkText('Drop')->click();
         $this->waitForElement(
             'cssSelector',
-            "button.submitOK"
+            'button.submitOK'
         )->click();
 
         $this->waitAjaxMessage();
 
         // test trigger
-        $this->dbQuery("INSERT INTO `test_table` (val) VALUES (1);");
-        $result = $this->dbQuery("SELECT val FROM `test_table2`;");
+        $this->dbQuery('INSERT INTO `test_table` (val) VALUES (1);');
+        $result = $this->dbQuery('SELECT val FROM `test_table2`;');
         $row = $result->fetch_assoc();
         $this->assertEquals(2, $row['val']);
 
         $result = $this->dbQuery(
-            "SHOW TRIGGERS FROM `" . $this->database_name . "`;"
+            'SHOW TRIGGERS FROM `' . $this->database_name . '`;'
         );
         $this->assertEquals(0, $result->num_rows);
     }
diff --git a/test/selenium/ExportTest.php b/test/selenium/ExportTest.php
index 341603f503..31282a98a3 100644
--- a/test/selenium/ExportTest.php
+++ b/test/selenium/ExportTest.php
@@ -27,14 +27,14 @@ class ExportTest extends TestBase
     {
         parent::setUp();
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "INSERT INTO `test_table` (val) VALUES (2);"
+            'INSERT INTO `test_table` (val) VALUES (2);'
         );
 
         $this->login();
@@ -95,7 +95,7 @@ class ExportTest extends TestBase
      */
     public function testTableExport($plugin, $expected): void
     {
-        $this->dbQuery("INSERT INTO `test_table` (val) VALUES (3);");
+        $this->dbQuery('INSERT INTO `test_table` (val) VALUES (3);');
 
         $this->navigateTable('test_table');
 
@@ -122,9 +122,9 @@ class ExportTest extends TestBase
             [
                 'SQL',
                 [
-                    "CREATE TABLE IF NOT EXISTS `test_table`",
-                    "INSERT INTO `test_table` (`id`, `val`) VALUES",
-                    "(1, 2)",
+                    'CREATE TABLE IF NOT EXISTS `test_table`',
+                    'INSERT INTO `test_table` (`id`, `val`) VALUES',
+                    '(1, 2)',
                 ],
             ],
             [
@@ -145,14 +145,14 @@ class ExportTest extends TestBase
     private function _doExport($type, $plugin)
     {
         $this->expandMore();
-        $this->waitForElement('partialLinkText', "Export")->click();
+        $this->waitForElement('partialLinkText', 'Export')->click();
         $this->waitAjax();
 
-        $this->waitForElement('id', "quick_or_custom");
-        $this->byCssSelector("label[for=radio_custom_export]")->click();
+        $this->waitForElement('id', 'quick_or_custom');
+        $this->byCssSelector('label[for=radio_custom_export]')->click();
 
         $this->selectByLabel(
-            $this->byId("plugins"),
+            $this->byId('plugins'),
             $plugin
         );
 
@@ -160,38 +160,38 @@ class ExportTest extends TestBase
             $this->scrollIntoView('databases_and_tables', 200);
             $this->byPartialLinkText('Unselect all')->click();
 
-            $this->byCssSelector("option[value=" . $this->database_name . "]")->click();
+            $this->byCssSelector('option[value=' . $this->database_name . ']')->click();
         }
 
         if ($type === 'table') {
             $this->scrollIntoView('radio_allrows_0');
-            $this->byCssSelector("label[for=radio_allrows_0]")->click();
-            $this->byName("limit_to")->clear();
-            $this->byName("limit_to")->sendKeys("1");
+            $this->byCssSelector('label[for=radio_allrows_0]')->click();
+            $this->byName('limit_to')->clear();
+            $this->byName('limit_to')->sendKeys('1');
         }
 
         $this->scrollIntoView('radio_view_as_text');
-        $this->byCssSelector("label[for=radio_view_as_text]")->click();
+        $this->byCssSelector('label[for=radio_view_as_text]')->click();
 
-        if ($plugin == "SQL") {
+        if ($plugin == 'SQL') {
             if ($type !== 'db') {
                 $this->scrollIntoView('radio_sql_structure_or_data_structure_and_data');
-                $this->byCssSelector("label[for=radio_sql_structure_or_data_structure_and_data]")->click();
+                $this->byCssSelector('label[for=radio_sql_structure_or_data_structure_and_data]')->click();
             }
 
             $this->scrollIntoView('checkbox_sql_if_not_exists');
             $ele = $this->byId('checkbox_sql_if_not_exists');
             if (! $ele->isSelected()) {
-                $this->byCssSelector("label[for=checkbox_sql_if_not_exists]")->click();
+                $this->byCssSelector('label[for=checkbox_sql_if_not_exists]')->click();
             }
         }
 
         $this->scrollToBottom();
 
-        $this->byId("buttonGo")->click();
+        $this->byId('buttonGo')->click();
         $this->waitAjax();
 
-        $text = $this->waitForElement('id', "textSQLDUMP")->getText();
+        $text = $this->waitForElement('id', 'textSQLDUMP')->getText();
         return $text;
     }
 }
diff --git a/test/selenium/ImportTest.php b/test/selenium/ImportTest.php
index 2f374a1bfc..cfedcb60c1 100644
--- a/test/selenium/ImportTest.php
+++ b/test/selenium/ImportTest.php
@@ -43,8 +43,8 @@ class ImportTest extends TestBase
         $this->assertGreaterThanOrEqual(2, $result->num_rows);
 
         // clear db
-        $this->dbQuery("DROP DATABASE test_import1");
-        $this->dbQuery("DROP DATABASE test_import2");
+        $this->dbQuery('DROP DATABASE test_import1');
+        $this->dbQuery('DROP DATABASE test_import2');
     }
 
     /**
@@ -56,13 +56,13 @@ class ImportTest extends TestBase
      */
     public function testDbImport()
     {
-        $this->dbQuery("CREATE DATABASE " . $this->database_name);
+        $this->dbQuery('CREATE DATABASE ' . $this->database_name);
         $this->navigateDatabase($this->database_name);
 
-        $this->_doImport("db");
+        $this->_doImport('db');
 
-        $this->dbQuery("USE " . $this->database_name);
-        $result = $this->dbQuery("SHOW TABLES");
+        $this->dbQuery('USE ' . $this->database_name);
+        $result = $this->dbQuery('SHOW TABLES');
         $this->assertEquals(1, $result->num_rows);
     }
 
@@ -76,17 +76,17 @@ class ImportTest extends TestBase
     public function testTableImport()
     {
         // setup the db
-        $this->dbQuery("CREATE DATABASE " . $this->database_name);
-        $this->dbQuery("USE " . $this->database_name);
+        $this->dbQuery('CREATE DATABASE ' . $this->database_name);
+        $this->dbQuery('USE ' . $this->database_name);
         $this->dbQuery(
-            "CREATE TABLE IF NOT EXISTS `test_table` (`val` int(11) NOT NULL)"
+            'CREATE TABLE IF NOT EXISTS `test_table` (`val` int(11) NOT NULL)'
         );
 
         $this->navigateTable('test_table');
 
-        $this->_doImport("table");
+        $this->_doImport('table');
 
-        $result = $this->dbQuery("SELECT * FROM test_table");
+        $result = $this->dbQuery('SELECT * FROM test_table');
         $this->assertEquals(2, $result->num_rows);
     }
 
@@ -99,23 +99,23 @@ class ImportTest extends TestBase
      */
     private function _doImport($type)
     {
-        $this->waitForElement('partialLinkText', "Import")->click();
+        $this->waitForElement('partialLinkText', 'Import')->click();
         $this->waitAjax();
         $this->waitForElement('id', 'input_import_file');
 
         $this->waitForElement('cssSelector', 'label[for=radio_local_import_file]')->click();
 
         $this->selectByValue(
-            $this->byName("local_import_file"),
-            $type . "_import.sql"
+            $this->byName('local_import_file'),
+            $type . '_import.sql'
         );
 
         $this->webDriver->wait(5);
 
         $this->webDriver->executeScript(
-            "window.scrollTo(0," .
+            'window.scrollTo(0,' .
             $this->byId('buttonGo')->getLocation()->getY()
-            . ")"
+            . ')'
         );
         $this->webDriver->wait(5);
         $this->scrollToBottom();
diff --git a/test/selenium/LoginTest.php b/test/selenium/LoginTest.php
index 574877bc10..37d6ef2864 100644
--- a/test/selenium/LoginTest.php
+++ b/test/selenium/LoginTest.php
@@ -36,7 +36,7 @@ class LoginTest extends TestBase
     public function testSuccessfulLogin()
     {
         $this->login();
-        $this->waitForElement('xpath', "//*[@id=\"server-breadcrumb\"]");
+        $this->waitForElement('xpath', '//*[@id="server-breadcrumb"]');
         $this->assertTrue($this->isSuccessLogin());
         $this->logOutIfLoggedIn();
     }
@@ -50,8 +50,8 @@ class LoginTest extends TestBase
      */
     public function testLoginWithWrongPassword()
     {
-        $this->login("Admin", "Admin");
-        $this->waitForElement('cssSelector', "alert-danger");
+        $this->login('Admin', 'Admin');
+        $this->waitForElement('cssSelector', 'alert-danger');
         $this->assertTrue($this->isUnsuccessLogin());
     }
 }
diff --git a/test/selenium/NormalizationTest.php b/test/selenium/NormalizationTest.php
index f1d84aad71..741323112e 100644
--- a/test/selenium/NormalizationTest.php
+++ b/test/selenium/NormalizationTest.php
@@ -27,12 +27,12 @@ class NormalizationTest extends TestBase
     {
         parent::setUp();
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " `val2` varchar(64) NOT NULL,"
-            . "PRIMARY KEY(id)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' `val2` varchar(64) NOT NULL,'
+            . 'PRIMARY KEY(id)'
+            . ')'
         );
 
         $this->login();
@@ -44,9 +44,9 @@ class NormalizationTest extends TestBase
 
         $this->waitAjax();
 
-        $this->waitForElement('id', "tablestructure");
+        $this->waitForElement('id', 'tablestructure');
         $this->byPartialLinkText('Normalize')->click();
-        $this->waitForElement('id', "normalizeTable");
+        $this->waitForElement('id', 'normalizeTable');
     }
 
     /**
@@ -62,7 +62,7 @@ class NormalizationTest extends TestBase
             $this->isElementPresent('cssSelector', 'fieldset')
         );
         $this->assertEquals(
-            "First step of normalization (1NF)",
+            'First step of normalization (1NF)',
             $this->byCssSelector('label[for=normalizeTo_1nf]')->getText()
         );
         $this->assertTrue(
@@ -84,7 +84,7 @@ class NormalizationTest extends TestBase
     private function _test1NFSteps()
     {
         $this->assertEquals(
-            "First step of normalization (1NF)",
+            'First step of normalization (1NF)',
             $this->byCssSelector('#page_content h3')->getText()
         );
         $this->assertTrue(
@@ -133,8 +133,8 @@ class NormalizationTest extends TestBase
             'xpath',
             "//legend[contains(., 'Step 1.2 Have a primary key')]"
         );
-        $text = $this->byCssSelector("#mainContent h4")->getText();
-        $this->assertStringContainsString("Primary key already exists.", $text);
+        $text = $this->byCssSelector('#mainContent h4')->getText();
+        $this->assertStringContainsString('Primary key already exists.', $text);
         $this->waitForElement(
             'xpath',
             "//legend[contains(., 'Step 1.3 Move repeating groups')]"
@@ -163,14 +163,14 @@ class NormalizationTest extends TestBase
             )
         );
         $this->byCssSelector('#extra input[value=val][type=checkbox]')->click();
-        $this->byCssSelector("#removeRedundant")->click();
+        $this->byCssSelector('#removeRedundant')->click();
         $this->waitForElement(
             'xpath',
             "//legend[contains(., 'End of step')]"
         );
         $this->assertStringContainsString(
             "The first step of normalization is complete for table 'test_table'.",
-            $this->byCssSelector("#mainContent h4")->getText()
+            $this->byCssSelector('#mainContent h4')->getText()
         );
     }
 }
diff --git a/test/selenium/ServerSettingsTest.php b/test/selenium/ServerSettingsTest.php
index b6a39bc542..1361beac10 100644
--- a/test/selenium/ServerSettingsTest.php
+++ b/test/selenium/ServerSettingsTest.php
@@ -28,7 +28,7 @@ class ServerSettingsTest extends TestBase
         parent::setUp();
         $this->login();
         $this->expandMore();
-        $this->waitForElement('partialLinkText', "Settings")->click();
+        $this->waitForElement('partialLinkText', 'Settings')->click();
         $this->waitAjax();
 
         $this->waitForElement(
@@ -69,12 +69,12 @@ class ServerSettingsTest extends TestBase
      */
     public function testHideDatabase()
     {
-        $this->byPartialLinkText("Features")->click();
+        $this->byPartialLinkText('Features')->click();
         $this->waitAjax();
 
         $this->waitForElement('xpath', "//a[contains(@href, '#Databases')]")->click();
 
-        $ele = $this->waitForElement('name', "Servers-1-hide_db");
+        $ele = $this->waitForElement('name', 'Servers-1-hide_db');
         $this->moveto($ele);
         $ele->sendKeys($this->database_name);
 
@@ -83,7 +83,7 @@ class ServerSettingsTest extends TestBase
             $this->isElementPresent('partialLinkText', $this->database_name)
         );
 
-        $this->waitForElement('name', "Servers-1-hide_db")->clear();
+        $this->waitForElement('name', 'Servers-1-hide_db')->clear();
         $this->_saveConfig();
         $this->assertTrue(
             $this->isElementPresent('partialLinkText', $this->database_name)
@@ -99,25 +99,25 @@ class ServerSettingsTest extends TestBase
      */
     public function testSettingsTabsAreDisplayed()
     {
-        $this->byPartialLinkText("SQL queries")->click();
+        $this->byPartialLinkText('SQL queries')->click();
         $this->waitAjax();
 
         $this->waitForElement('className', 'tabs');
 
-        $this->byPartialLinkText("SQL Query box")->click();
+        $this->byPartialLinkText('SQL Query box')->click();
         $this->assertTrue(
-            $this->byId("Sql_box")->isDisplayed()
+            $this->byId('Sql_box')->isDisplayed()
         );
         $this->assertFalse(
-            $this->byId("Sql_queries")->isDisplayed()
+            $this->byId('Sql_queries')->isDisplayed()
         );
 
         $this->byCssSelector("a[href='#Sql_queries']")->click();
         $this->assertFalse(
-            $this->byId("Sql_box")->isDisplayed()
+            $this->byId('Sql_box')->isDisplayed()
         );
         $this->assertTrue(
-            $this->byId("Sql_queries")->isDisplayed()
+            $this->byId('Sql_queries')->isDisplayed()
         );
     }
 
@@ -130,20 +130,20 @@ class ServerSettingsTest extends TestBase
      */
     public function testHideLogo()
     {
-        $this->byPartialLinkText("Navigation panel")->click();
+        $this->byPartialLinkText('Navigation panel')->click();
         $this->waitAjax();
 
-        $this->waitForElement('name', "NavigationDisplayLogo")
+        $this->waitForElement('name', 'NavigationDisplayLogo')
             ->click();
         $this->_saveConfig();
         $this->assertFalse(
-            $this->isElementPresent('id', "imgpmalogo")
+            $this->isElementPresent('id', 'imgpmalogo')
         );
 
         $this->byCssSelector("a[href='#NavigationDisplayLogo']")->click();
         $this->_saveConfig();
         $this->assertTrue(
-            $this->isElementPresent('id', "imgpmalogo")
+            $this->isElementPresent('id', 'imgpmalogo')
         );
     }
 }
diff --git a/test/selenium/SqlQueryTest.php b/test/selenium/SqlQueryTest.php
index 13b5137724..2c931a111d 100644
--- a/test/selenium/SqlQueryTest.php
+++ b/test/selenium/SqlQueryTest.php
@@ -28,14 +28,14 @@ class SqlQueryTest extends TestBase
         parent::setUp();
 
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "INSERT INTO `test_table` (val) VALUES (2), (3), (4), (5);"
+            'INSERT INTO `test_table` (val) VALUES (2), (3), (4), (5);'
         );
         $this->login();
     }
diff --git a/test/selenium/Table/BrowseTest.php b/test/selenium/Table/BrowseTest.php
index 2cc067122a..9b2653b1a4 100644
--- a/test/selenium/Table/BrowseTest.php
+++ b/test/selenium/Table/BrowseTest.php
@@ -30,15 +30,15 @@ class BrowseTest extends TestBase
     {
         parent::setUp();
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `name` varchar(20) NOT NULL,"
-            . " `datetimefield` datetime NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `name` varchar(20) NOT NULL,'
+            . ' `datetimefield` datetime NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "INSERT INTO `test_table` (`id`, `name`, `datetimefield`) VALUES"
+            'INSERT INTO `test_table` (`id`, `name`, `datetimefield`) VALUES'
             . " (1, 'abcd', '2011-01-20 02:00:02'),"
             . " (2, 'foo', '2010-01-20 02:00:02'),"
             . " (3, 'Abcd', '2012-01-20 02:00:02')"
@@ -60,79 +60,79 @@ class BrowseTest extends TestBase
     public function testSortRecords()
     {
         // case 1
-        $this->byPartialLinkText("name")->click();
+        $this->byPartialLinkText('name')->click();
         $this->waitAjax();
 
         $this->assertEquals(
-            "1",
+            '1',
             $this->getCellByTableClass('table_results', 1, 5)
         );
 
         $this->assertEquals(
-            "3",
+            '3',
             $this->getCellByTableClass('table_results', 2, 5)
         );
 
         $this->assertEquals(
-            "2",
+            '2',
             $this->getCellByTableClass('table_results', 3, 5)
         );
 
         // case 2
-        $this->byPartialLinkText("name")->click();
+        $this->byPartialLinkText('name')->click();
         $this->waitAjax();
 
         $this->assertEquals(
-            "2",
+            '2',
             $this->getCellByTableClass('table_results', 1, 5)
         );
 
         $this->assertEquals(
-            "1",
+            '1',
             $this->getCellByTableClass('table_results', 2, 5)
         );
 
         $this->assertEquals(
-            "3",
+            '3',
             $this->getCellByTableClass('table_results', 3, 5)
         );
 
         // case 2
-        $this->byLinkText("datetimefield")->click();
+        $this->byLinkText('datetimefield')->click();
         $this->waitAjax();
 
         $this->getCellByTableClass('table_results', 1, 5);
         $this->assertEquals(
-            "3",
+            '3',
             $this->getCellByTableClass('table_results', 1, 5)
         );
 
         $this->assertEquals(
-            "1",
+            '1',
             $this->getCellByTableClass('table_results', 2, 5)
         );
 
         $this->assertEquals(
-            "2",
+            '2',
             $this->getCellByTableClass('table_results', 3, 5)
         );
 
         // case 4
-        $this->byPartialLinkText("datetimefield")->click();
+        $this->byPartialLinkText('datetimefield')->click();
         $this->waitAjax();
 
         $this->assertEquals(
-            "2",
+            '2',
             $this->getCellByTableClass('table_results', 1, 5)
         );
 
         $this->assertEquals(
-            "1",
+            '1',
             $this->getCellByTableClass('table_results', 2, 5)
         );
 
         $this->assertEquals(
-            "3",
+            '3',
             $this->getCellByTableClass('table_results', 3, 5)
         );
     }
@@ -147,52 +147,52 @@ class BrowseTest extends TestBase
     public function testChangeRecords()
     {
         $ele = $this->byCssSelector(
-            "table.table_results tbody tr:nth-child(2) td:nth-child(2)"
+            'table.table_results tbody tr:nth-child(2) td:nth-child(2)'
         );
         $this->moveto($ele);
         $this->click();
 
-        $this->waitForElement('id', "insertForm");
+        $this->waitForElement('id', 'insertForm');
 
         $this->waitAjax();
-        $this->waitForElement('id', "insertForm");
+        $this->waitForElement('id', 'insertForm');
 
         $this->assertEquals(
-            "2",
-            $this->byId("field_1_3")->getAttribute('value')
+            '2',
+            $this->byId('field_1_3')->getAttribute('value')
         );
 
         $this->assertEquals(
-            "foo",
-            $this->byId("field_2_3")->getAttribute('value')
+            'foo',
+            $this->byId('field_2_3')->getAttribute('value')
         );
 
         $this->assertEquals(
-            "2010-01-20 02:00:02",
-            $this->byId("field_3_3")->getAttribute('value')
+            '2010-01-20 02:00:02',
+            $this->byId('field_3_3')->getAttribute('value')
         );
 
-        $this->byId("field_3_3")->clear();
-        $this->byId("field_3_3")->sendKeys("2009-01-2");
+        $this->byId('field_3_3')->clear();
+        $this->byId('field_3_3')->sendKeys('2009-01-2');
         // shorter date to prevent error,
         // automatically gets appended with 00:00:00
 
-        $this->byId("field_2_3")->clear();
-        $this->byId("field_2_3")->sendKeys("foobar");
+        $this->byId('field_2_3')->clear();
+        $this->byId('field_2_3')->sendKeys('foobar');
 
-        $this->byId("buttonYes")->click();
+        $this->byId('buttonYes')->click();
 
         $this->waitAjax();
-        $success = $this->waitForElement('className', "alert-success");
-        $this->assertStringContainsString("1 row affected", $success->getText());
+        $success = $this->waitForElement('className', 'alert-success');
+        $this->assertStringContainsString('1 row affected', $success->getText());
 
         $this->assertEquals(
-            "foobar",
+            'foobar',
             $this->getCellByTableClass('table_results', 2, 6)
         );
 
         $this->assertEquals(
-            "2009-01-02 00:00:00",
+            '2009-01-02 00:00:00',
             $this->getCellByTableClass('table_results', 2, 7)
         );
     }
@@ -207,7 +207,7 @@ class BrowseTest extends TestBase
     public function testChangeRecordsByDoubleClick()
     {
         $element = $this->byCssSelector(
-            "table.table_results tbody tr:nth-child(1) td:nth-child(6)"
+            'table.table_results tbody tr:nth-child(1) td:nth-child(6)'
         );
 
         $this->moveto($element);
@@ -218,23 +218,23 @@ class BrowseTest extends TestBase
                 'xpath',
                 "//div[not(contains(@style,'display: none;'))]//textarea[contains(@class, 'edit_box')]"
             )->getAttribute('value'),
-            "abcd"
+            'abcd'
         );
 
-        $this->byCssSelector("textarea.edit_box")->clear();
-        $this->byCssSelector("textarea.edit_box")->sendKeys("abcde");
+        $this->byCssSelector('textarea.edit_box')->clear();
+        $this->byCssSelector('textarea.edit_box')->sendKeys('abcde');
 
         $this->keys(WebDriverKeys::RETURN_KEY);
 
         $this->waitAjax();
         $success = $this->waitForElement(
             'cssSelector',
-            "span.ajax_notification .alert-success"
+            'span.ajax_notification .alert-success'
         );
-        $this->assertStringContainsString("1 row affected", $success->getText());
+        $this->assertStringContainsString('1 row affected', $success->getText());
 
         $this->assertEquals(
-            "abcde",
+            'abcde',
             $this->getCellByTableClass('table_results', 1, 6)
         );
     }
@@ -249,41 +249,41 @@ class BrowseTest extends TestBase
     public function testCopyRecords()
     {
         $ele = $this->byCssSelector(
-            "table.table_results tbody tr:nth-child(3) td:nth-child(3)"
+            'table.table_results tbody tr:nth-child(3) td:nth-child(3)'
         );
         $this->moveto($ele);
         $this->click();
-        $this->waitForElement('id', "insertForm");
+        $this->waitForElement('id', 'insertForm');
 
         $this->assertEquals(
-            "Abcd",
-            $this->byId("field_2_3")->getAttribute('value')
+            'Abcd',
+            $this->byId('field_2_3')->getAttribute('value')
         );
 
         $this->assertEquals(
-            "2012-01-20 02:00:02",
-            $this->byId("field_3_3")->getAttribute('value')
+            '2012-01-20 02:00:02',
+            $this->byId('field_3_3')->getAttribute('value')
         );
 
-        $this->byId("field_2_3")->clear();
-        $this->byId("field_2_3")->sendKeys("ABCDEFG");
+        $this->byId('field_2_3')->clear();
+        $this->byId('field_2_3')->sendKeys('ABCDEFG');
 
-        $this->byId("field_3_3")->clear();
-        $this->byId("field_3_3")->sendKeys("2012-01-02");
+        $this->byId('field_3_3')->clear();
+        $this->byId('field_3_3')->sendKeys('2012-01-02');
 
-        $this->waitForElement('id', "buttonYes")->click();
+        $this->waitForElement('id', 'buttonYes')->click();
 
         $this->waitAjax();
-        $success = $this->waitForElement('className', "alert-success");
-        $this->assertStringContainsString("1 row inserted", $success->getText());
+        $success = $this->waitForElement('className', 'alert-success');
+        $this->assertStringContainsString('1 row inserted', $success->getText());
 
         $this->assertEquals(
-            "ABCDEFG",
+            'ABCDEFG',
             $this->getCellByTableClass('table_results', 4, 6)
         );
 
         $this->assertEquals(
-            "2012-01-02 00:00:00",
+            '2012-01-02 00:00:00',
             $this->getCellByTableClass('table_results', 4, 7)
         );
     }
@@ -299,31 +299,31 @@ class BrowseTest extends TestBase
     {
         $this->expandMore();
 
-        $this->byPartialLinkText("Search")->click();
-        $this->waitForElement('id', "tbl_search_form");
+        $this->byPartialLinkText('Search')->click();
+        $this->waitForElement('id', 'tbl_search_form');
 
-        $this->byId("fieldID_1")->sendKeys("abcd");
+        $this->byId('fieldID_1')->sendKeys('abcd');
         $this->selectByLabel(
-            $this->byName("criteriaColumnOperators[1]"),
+            $this->byName('criteriaColumnOperators[1]'),
             'LIKE %...%'
         );
 
         $this->scrollToBottom();
-        $elem = $this->waitForElement('cssSelector', ".tblFooters input[name=submit]");
+        $elem = $this->waitForElement('cssSelector', '.tblFooters input[name=submit]');
         $this->moveto($elem);
         $elem->click();
 
         $this->waitAjax();
-        $success = $this->waitForElement('className', "alert-success");
-        $this->assertStringContainsString("Showing rows", $success->getText());
+        $success = $this->waitForElement('className', 'alert-success');
+        $this->assertStringContainsString('Showing rows', $success->getText());
 
         $this->assertEquals(
-            "1",
+            '1',
             $this->getCellByTableClass('table_results', 1, 5)
         );
 
         $this->assertEquals(
-            "3",
+            '3',
             $this->getCellByTableClass('table_results', 2, 5)
         );
     }
@@ -337,22 +337,22 @@ class BrowseTest extends TestBase
      */
     public function testDeleteRecords()
     {
-        $this->byId("id_rows_to_delete1_left")->click();
-        $this->byId("id_rows_to_delete2_left")->click();
+        $this->byId('id_rows_to_delete1_left')->click();
+        $this->byId('id_rows_to_delete2_left')->click();
 
-        $this->byCssSelector("button[value=delete]")->click();
-        $this->waitForElement('cssSelector', "fieldset.confirmation");
+        $this->byCssSelector('button[value=delete]')->click();
+        $this->waitForElement('cssSelector', 'fieldset.confirmation');
 
-        $this->byId("buttonYes")->click();
+        $this->byId('buttonYes')->click();
 
         $this->waitAjax();
-        $success = $this->waitForElement('className', "alert-success");
-        $this->assertStringContainsString("Showing rows", $success->getText());
+        $success = $this->waitForElement('className', 'alert-success');
+        $this->assertStringContainsString('Showing rows', $success->getText());
 
         $this->assertFalse(
             $this->isElementPresent(
                 'cssSelector',
-                "table.table_results tbody tr:nth-child(2)"
+                'table.table_results tbody tr:nth-child(2)'
             )
         );
     }
diff --git a/test/selenium/Table/CreateTest.php b/test/selenium/Table/CreateTest.php
index a8b6726d1e..5ff25dfd35 100644
--- a/test/selenium/Table/CreateTest.php
+++ b/test/selenium/Table/CreateTest.php
@@ -49,26 +49,26 @@ class CreateTest extends TestBase
 
         $this->waitForElement('id', 'create_table_form_minimal');
         $this->byCssSelector(
-            "form#create_table_form_minimal input[name=table]"
-        )->sendKeys("test_table");
-        $this->byName("num_fields")->clear();
-        $this->byName("num_fields")->sendKeys("4");
+            'form#create_table_form_minimal input[name=table]'
+        )->sendKeys('test_table');
+        $this->byName('num_fields')->clear();
+        $this->byName('num_fields')->sendKeys('4');
         $this->byCssSelector('input[value=Go]')->click();
 
         $this->waitAjax();
         $this->waitForElement('name', 'do_save_data');
 
-        $this->waitForElement('id', "field_1_7")->click(); // null
-        $this->waitForElement('id', "field_0_9")->click(); // auto increment
+        $this->waitForElement('id', 'field_1_7')->click(); // null
+        $this->waitForElement('id', 'field_0_9')->click(); // auto increment
 
         // column details
         $column_text_details = [
-            "field_0_1" => "test_id",
-            "field_0_3" => "14",
-            "field_0_10" => "comm1",
-            "field_1_1" => "test_column",
-            "field_1_3" => "10",
-            "field_1_10" => "comm2",
+            'field_0_1' => 'test_id',
+            'field_0_3' => '14',
+            'field_0_10' => 'comm1',
+            'field_1_1' => 'test_column',
+            'field_1_3' => '10',
+            'field_1_10' => 'comm2',
         ];
 
         foreach ($column_text_details as $field => $val) {
@@ -76,10 +76,10 @@ class CreateTest extends TestBase
         }
 
         $column_dropdown_details = [
-            "field_0_6" => "UNSIGNED",
-            "field_1_2" => "VARCHAR",
-            "field_1_5" => "utf8_general_ci",
-            "field_1_4" => "As defined:",
+            'field_0_6' => 'UNSIGNED',
+            'field_1_2' => 'VARCHAR',
+            'field_1_5' => 'utf8_general_ci',
+            'field_1_4' => 'As defined:',
         ];
 
         foreach ($column_dropdown_details as $selector => $value) {
@@ -89,10 +89,10 @@ class CreateTest extends TestBase
             )->click();
         }
 
-        $this->byName("field_default_value[1]")->sendKeys("def");
+        $this->byName('field_default_value[1]')->sendKeys('def');
 
         $this->scrollToBottom();
-        $ele = $this->waitForElement('name', "do_save_data");
+        $ele = $this->waitForElement('name', 'do_save_data');
         $this->moveto($ele);
         // post
         $ele->click();
@@ -103,7 +103,7 @@ class CreateTest extends TestBase
 
         $this->waitAjax();
 
-        $this->waitForElement('partialLinkText', "test_table");
+        $this->waitForElement('partialLinkText', 'test_table');
 
         $this->_tableStructureAssertions();
     }
@@ -123,43 +123,43 @@ class CreateTest extends TestBase
         $this->waitAjax();
 
         // go to structure page
-        $this->waitForElement('partialLinkText', "Structure")->click();
+        $this->waitForElement('partialLinkText', 'Structure')->click();
 
-        $this->waitForElement('id', "tablestructure");
+        $this->waitForElement('id', 'tablestructure');
         $this->waitForElement('id', 'table_strucuture_id');
 
         // make assertions for first row
         $this->assertStringContainsString(
-            "test_id",
+            'test_id',
             $this->byCssSelector('label[for=checkbox_row_1]')->getText()
         );
 
         $this->assertEquals(
-            "int(14)",
+            'int(14)',
             $this->getCellByTableId('tablestructure', 1, 4)
         );
 
         $this->assertEquals(
-            "UNSIGNED",
+            'UNSIGNED',
             $this->getCellByTableId('tablestructure', 1, 6)
         );
 
         $this->assertEquals(
-            "No",
+            'No',
             $this->getCellByTableId('tablestructure', 1, 7)
         );
 
         $this->assertEquals(
-            "None",
+            'None',
             $this->getCellByTableId('tablestructure', 1, 8)
         );
         $this->assertEquals(
-            "comm1",
+            'comm1',
             $this->getCellByTableId('tablestructure', 1, 9)
         );
 
         $this->assertEquals(
-            "AUTO_INCREMENT",
+            'AUTO_INCREMENT',
             $this->getCellByTableId('tablestructure', 1, 10)
         );
 
@@ -173,27 +173,27 @@ class CreateTest extends TestBase
 
         // make assertions for second row
         $this->assertStringContainsString(
-            "test_column",
+            'test_column',
             $this->byCssSelector('label[for=checkbox_row_2]')->getText()
         );
 
         $this->assertEquals(
-            "varchar(10)",
+            'varchar(10)',
             $this->getCellByTableId('tablestructure', 2, 4)
         );
 
         $this->assertEquals(
-            "utf8_general_ci",
+            'utf8_general_ci',
             $this->getCellByTableId('tablestructure', 2, 5)
         );
 
         $this->assertEquals(
-            "Yes",
+            'Yes',
             $this->getCellByTableId('tablestructure', 2, 7)
         );
 
         $this->assertEquals(
-            "def",
+            'def',
             $this->getCellByTableId('tablestructure', 2, 8)
         );
 
diff --git a/test/selenium/Table/InsertTest.php b/test/selenium/Table/InsertTest.php
index dc31e091b9..84fed6c2bc 100644
--- a/test/selenium/Table/InsertTest.php
+++ b/test/selenium/Table/InsertTest.php
@@ -30,12 +30,12 @@ class InsertTest extends TestBase
     {
         parent::setUp();
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `name` varchar(20) NOT NULL,"
-            . " `datetimefield` datetime NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `name` varchar(20) NOT NULL,'
+            . ' `datetimefield` datetime NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
 
         $this->login();
@@ -58,44 +58,44 @@ class InsertTest extends TestBase
         $this->waitAjax();
         $this->expandMore();
 
-        $this->byPartialLinkText("Insert")->click();
+        $this->byPartialLinkText('Insert')->click();
         $this->waitAjax();
-        $this->waitForElement('id', "insertForm");
+        $this->waitForElement('id', 'insertForm');
 
         // shorter date to prevent error,
         // automatically gets appended with 00:00:00
-        $this->byId("field_3_3")->click()->sendKeys("2011-01-2");
+        $this->byId('field_3_3')->click()->sendKeys('2011-01-2');
 
-        $this->byId("field_1_3")->sendKeys("1");
-        $this->byId("field_2_3")->sendKeys("abcd");
+        $this->byId('field_1_3')->sendKeys('1');
+        $this->byId('field_2_3')->sendKeys('abcd');
 
         // shorter date to prevent error,
         // automatically gets appended with 00:00:00
-        $this->byId("field_6_3")->click()->sendKeys("2012-01-2");
+        $this->byId('field_6_3')->click()->sendKeys('2012-01-2');
 
-        $this->byId("field_5_3")->sendKeys("foo");
+        $this->byId('field_5_3')->sendKeys('foo');
 
         $this->selectByLabel(
-            $this->byName("after_insert"),
+            $this->byName('after_insert'),
             'Insert another new row'
         );
 
         // post
-        $this->byId("buttonYes")->click();
+        $this->byId('buttonYes')->click();
         $this->waitAjax();
 
-        $ele = $this->waitForElement('className', "alert-success");
-        $this->assertStringContainsString("2 rows inserted", $ele->getText());
+        $ele = $this->waitForElement('className', 'alert-success');
+        $this->assertStringContainsString('2 rows inserted', $ele->getText());
 
         // shorter date to prevent error,
         // automatically gets appended with 00:00:00
-        $this->byId("field_3_3")->click()->sendKeys("2013-01-2");
+        $this->byId('field_3_3')->click()->sendKeys('2013-01-2');
 
-        $this->byId("field_2_3")->sendKeys("Abcd");
+        $this->byId('field_2_3')->sendKeys('Abcd');
 
         // post
         $this->byCssSelector(
-            "input[value=Go]"
+            'input[value=Go]'
         )->click();
 
         $this->waitAjax();
@@ -105,7 +105,7 @@ class InsertTest extends TestBase
             'xpath',
             "//div[contains(@class, 'alert-success') and not(contains(@class, 'message'))]"
         );
-        $this->assertStringContainsString("1 row inserted", $ele->getText());
+        $this->assertStringContainsString('1 row inserted', $ele->getText());
 
         $this->_assertDataPresent();
     }
@@ -117,53 +117,53 @@ class InsertTest extends TestBase
      */
     private function _assertDataPresent()
     {
-        $this->byPartialLinkText("Browse")->click();
+        $this->byPartialLinkText('Browse')->click();
 
         $this->waitAjax();
-        $this->waitForElement('cssSelector', "table.table_results");
+        $this->waitForElement('cssSelector', 'table.table_results');
 
         $this->assertEquals(
-            "1",
+            '1',
             $this->getCellByTableClass('table_results', 1, 5)
         );
 
         $this->assertEquals(
-            "abcd",
+            'abcd',
             $this->getCellByTableClass('table_results', 1, 6)
         );
 
         $this->assertEquals(
-            "2011-01-02 00:00:00",
+            '2011-01-02 00:00:00',
             $this->getCellByTableClass('table_results', 1, 7)
         );
 
         $this->assertEquals(
-            "2",
+            '2',
             $this->getCellByTableClass('table_results', 2, 5)
         );
 
         $this->assertEquals(
-            "foo",
+            'foo',
             $this->getCellByTableClass('table_results', 2, 6)
         );
 
         $this->assertEquals(
-            "2012-01-02 00:00:00",
+            '2012-01-02 00:00:00',
             $this->getCellByTableClass('table_results', 2, 7)
         );
 
         $this->assertEquals(
-            "4",
+            '4',
             $this->getCellByTableClass('table_results', 3, 5)
         );
 
         $this->assertEquals(
-            "Abcd",
+            'Abcd',
             $this->getCellByTableClass('table_results', 3, 6)
         );
 
         $this->assertEquals(
-            "2013-01-02 00:00:00",
+            '2013-01-02 00:00:00',
             $this->getCellByTableClass('table_results', 3, 7)
         );
     }
diff --git a/test/selenium/Table/OperationsTest.php b/test/selenium/Table/OperationsTest.php
index 37efe7f3e6..32c7c80888 100644
--- a/test/selenium/Table/OperationsTest.php
+++ b/test/selenium/Table/OperationsTest.php
@@ -32,15 +32,15 @@ class OperationsTest extends TestBase
         // MYISAM ENGINE to allow for column-based order selection
         // while table also has a PRIMARY key
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " `val2` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ") ENGINE=MYISAM"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' `val2` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ') ENGINE=MYISAM'
         );
-        $this->dbQuery("INSERT INTO test_table (val, val2) VALUES (22, 33)");
-        $this->dbQuery("INSERT INTO test_table (val, val2) VALUES (33, 44)");
+        $this->dbQuery('INSERT INTO test_table (val, val2) VALUES (22, 33)');
+        $this->dbQuery('INSERT INTO test_table (val, val2) VALUES (33, 44)');
 
         $this->login();
         $this->navigateTable('test_table');
@@ -67,11 +67,11 @@ class OperationsTest extends TestBase
     public function testChangeTableOrder()
     {
         $this->selectByLabel(
-            $this->byName("order_field"),
+            $this->byName('order_field'),
             'val'
         );
 
-        $this->byId("order_order_desc")->click();
+        $this->byId('order_order_desc')->click();
         $this->byCssSelector(
             "form#alterTableOrderby input[type='submit']"
         )->click();
@@ -84,13 +84,13 @@ class OperationsTest extends TestBase
             . "contains(., 'Your SQL query has been executed successfully')]"
         );
 
-        $this->byPartialLinkText("Browse")->click();
+        $this->byPartialLinkText('Browse')->click();
 
         $this->waitAjax();
-        $this->waitForElement('cssSelector', "table.table_results");
+        $this->waitForElement('cssSelector', 'table.table_results');
 
         $this->assertEquals(
-            "2",
+            '2',
             $this->getCellByTableClass('table_results', 1, 5)
         );
     }
@@ -105,7 +105,7 @@ class OperationsTest extends TestBase
     public function testMoveTable()
     {
         $this->byCssSelector("form#moveTableForm input[name='new_name']")
-            ->sendKeys("2");
+            ->sendKeys('2');
 
         $this->byCssSelector("form#moveTableForm input[type='submit']")->click();
         $this->waitAjax();
@@ -114,15 +114,15 @@ class OperationsTest extends TestBase
             'xpath',
             "//div[@class='alert alert-success' and "
             . "contains(., 'Table `" . $this->database_name
-            . "`.`test_table` has been "
-            . "moved to `" . $this->database_name . "`.`test_table2`.')]"
+            . '`.`test_table` has been '
+            . 'moved to `' . $this->database_name . "`.`test_table2`.')]"
         );
 
-        $result = $this->dbQuery("SHOW TABLES");
+        $result = $this->dbQuery('SHOW TABLES');
         $row = $result->fetch_assoc();
         $this->assertEquals(
-            "test_table2",
-            $row["Tables_in_" . $this->database_name]
+            'test_table2',
+            $row['Tables_in_' . $this->database_name]
         );
     }
 
@@ -136,9 +136,9 @@ class OperationsTest extends TestBase
     public function testRenameTable()
     {
         $this->byCssSelector("form#tableOptionsForm input[name='new_name']")
-            ->sendKeys("2");
+            ->sendKeys('2');
 
-        $this->byName("comment")->sendKeys("foobar");
+        $this->byName('comment')->sendKeys('foobar');
 
         $this->scrollIntoView('tableOptionsForm');
         $this->waitUntilElementIsVisible('cssSelector', 'form#tableOptionsForm', 30);
@@ -151,11 +151,11 @@ class OperationsTest extends TestBase
             . "contains(., 'Table test_table has been renamed to test_table2')]"
         );
 
-        $result = $this->dbQuery("SHOW TABLES");
+        $result = $this->dbQuery('SHOW TABLES');
         $row = $result->fetch_assoc();
         $this->assertEquals(
-            "test_table2",
-            $row["Tables_in_" . $this->database_name]
+            'test_table2',
+            $row['Tables_in_' . $this->database_name]
         );
     }
 
@@ -170,7 +170,7 @@ class OperationsTest extends TestBase
     {
         $this->scrollIntoView('copyTable');
         $this->waitUntilElementIsVisible('cssSelector', 'form#copyTable', 30);
-        $this->byCssSelector("form#copyTable input[name='new_name']")->sendKeys("2");
+        $this->byCssSelector("form#copyTable input[name='new_name']")->sendKeys('2');
         $this->byCssSelector("label[for='what_data']")->click();
         $this->byCssSelector("form#copyTable input[type='submit']")->click();
         $this->waitAjax();
@@ -179,15 +179,15 @@ class OperationsTest extends TestBase
             'xpath',
             "//div[@class='alert alert-success' and "
             . "contains(., 'Table `" . $this->database_name
-            . "`.`test_table` has been "
-            . "copied to `" . $this->database_name . "`.`test_table2`.')]"
+            . '`.`test_table` has been '
+            . 'copied to `' . $this->database_name . "`.`test_table2`.')]"
         );
 
-        $result = $this->dbQuery("SELECT COUNT(*) as c FROM test_table2");
+        $result = $this->dbQuery('SELECT COUNT(*) as c FROM test_table2');
         $row = $result->fetch_assoc();
         $this->assertEquals(
             2,
-            $row["c"]
+            $row['c']
         );
     }
 
@@ -202,8 +202,8 @@ class OperationsTest extends TestBase
     {
         $this->scrollToBottom();
         $this->waitUntilElementIsVisible('id', 'drop_tbl_anchor', 30);
-        $this->byId("truncate_tbl_anchor")->click();
-        $this->byCssSelector("button.submitOK")->click();
+        $this->byId('truncate_tbl_anchor')->click();
+        $this->byCssSelector('button.submitOK')->click();
         $this->waitAjax();
 
         $this->waitForElement(
@@ -212,11 +212,11 @@ class OperationsTest extends TestBase
             . "contains(., 'MySQL returned an empty result set')]"
         );
 
-        $result = $this->dbQuery("SELECT COUNT(*) as c FROM test_table");
+        $result = $this->dbQuery('SELECT COUNT(*) as c FROM test_table');
         $row = $result->fetch_assoc();
         $this->assertEquals(
             0,
-            $row["c"]
+            $row['c']
         );
     }
 
@@ -231,8 +231,8 @@ class OperationsTest extends TestBase
     {
         $this->scrollToBottom();
         $this->waitUntilElementIsVisible('id', 'drop_tbl_anchor', 30);
-        $this->byId("drop_tbl_anchor")->click();
-        $this->byCssSelector("button.submitOK")->click();
+        $this->byId('drop_tbl_anchor')->click();
+        $this->byCssSelector('button.submitOK')->click();
         $this->waitAjax();
 
         $this->waitForElement(
@@ -246,7 +246,7 @@ class OperationsTest extends TestBase
             "//a[@class='tabactive' and contains(., 'Structure')]"
         );
 
-        $result = $this->dbQuery("SHOW TABLES");
+        $result = $this->dbQuery('SHOW TABLES');
         $this->assertEquals(
             0,
             $result->num_rows
diff --git a/test/selenium/Table/StructureTest.php b/test/selenium/Table/StructureTest.php
index 799ed8e655..b58a031b9d 100644
--- a/test/selenium/Table/StructureTest.php
+++ b/test/selenium/Table/StructureTest.php
@@ -29,12 +29,12 @@ class StructureTest extends TestBase
     {
         parent::setUp();
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " `val2` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' `val2` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
 
         $this->login();
@@ -46,7 +46,7 @@ class StructureTest extends TestBase
         )->click();
 
         $this->waitAjax();
-        $this->waitForElement('id', "tablestructure");
+        $this->waitForElement('id', 'tablestructure');
     }
 
     /**
@@ -64,9 +64,9 @@ class StructureTest extends TestBase
         )->click();
         $this->waitAjax();
 
-        $this->waitForElement('className', "append_fields_form");
+        $this->waitForElement('className', 'append_fields_form');
 
-        $this->byId("field_0_1")->sendKeys('val3');
+        $this->byId('field_0_1')->sendKeys('val3');
         $this->byCssSelector("input[name='do_save_data']")->click();
 
         $this->waitAjax();
@@ -76,17 +76,17 @@ class StructureTest extends TestBase
             . "'Table test_table has been altered successfully')]"
         );
 
-        $this->byPartialLinkText("Structure")->click();
+        $this->byPartialLinkText('Structure')->click();
         $this->waitAjax();
-        $this->waitForElement('id', "tablestructure");
+        $this->waitForElement('id', 'tablestructure');
 
         $this->assertEquals(
-            "val3",
+            'val3',
             $this->byCssSelector('label[for=checkbox_row_4]')->getText()
         );
 
         $this->assertEquals(
-            "int(11)",
+            'int(11)',
             $this->getCellByTableId('tablestructure', 4, 4)
         );
     }
@@ -101,15 +101,15 @@ class StructureTest extends TestBase
     public function testChangeColumn()
     {
         $this->byCssSelector(
-            "#tablestructure tbody tr:nth-child(2) td:nth-child(11)"
+            '#tablestructure tbody tr:nth-child(2) td:nth-child(11)'
         )->click();
         $this->waitAjax();
 
-        $this->waitForElement('className', "append_fields_form");
+        $this->waitForElement('className', 'append_fields_form');
 
-        $this->assertEquals("val", $this->byId("field_0_1")->getAttribute('value'));
-        $this->byId("field_0_1")->clear();
-        $this->byId("field_0_1")->sendKeys('val3');
+        $this->assertEquals('val', $this->byId('field_0_1')->getAttribute('value'));
+        $this->byId('field_0_1')->clear();
+        $this->byId('field_0_1')->sendKeys('val3');
         $this->byCssSelector("input[name='do_save_data']")->click();
 
         $this->waitForElement(
@@ -118,13 +118,13 @@ class StructureTest extends TestBase
             . "'Table test_table has been altered successfully')]"
         );
 
-        $this->byPartialLinkText("Structure")->click();
+        $this->byPartialLinkText('Structure')->click();
         $this->waitAjax();
 
-        $this->waitForElement('id', "tablestructure");
+        $this->waitForElement('id', 'tablestructure');
 
         $this->assertEquals(
-            "val3",
+            'val3',
             $this->waitForElement('cssSelector', 'label[for=checkbox_row_2]')->getText()
         );
     }
diff --git a/test/selenium/TestBase.php b/test/selenium/TestBase.php
index fe220020d8..e2942b2e56 100644
--- a/test/selenium/TestBase.php
+++ b/test/selenium/TestBase.php
@@ -223,10 +223,10 @@ abstract class TestBase extends TestCase
      */
     private function navigateTo(string $url): void
     {
-        if (substr($GLOBALS['TESTSUITE_URL'], -1) === "/") {
+        if (substr($GLOBALS['TESTSUITE_URL'], -1) === '/') {
             $url = $GLOBALS['TESTSUITE_URL'] . $url;
         } else {
-            $url = $GLOBALS['TESTSUITE_URL'] . "/" . $url;
+            $url = $GLOBALS['TESTSUITE_URL'] . '/' . $url;
         }
 
         $this->webDriver->get($url);
@@ -552,7 +552,7 @@ abstract class TestBase extends TestCase
      */
     public function isSuccessLogin()
     {
-        return $this->isElementPresent('xpath', "//*[@id=\"server-breadcrumb\"]");
+        return $this->isElementPresent('xpath', '//*[@id="server-breadcrumb"]');
     }
 
     /**
@@ -562,7 +562,7 @@ abstract class TestBase extends TestCase
      */
     public function isUnsuccessLogin()
     {
-        return $this->isElementPresent('cssSelector', "div.error");
+        return $this->isElementPresent('cssSelector', 'div.error');
     }
 
     /**
@@ -572,7 +572,7 @@ abstract class TestBase extends TestCase
      */
     public function gotoHomepage()
     {
-        $e = $this->byPartialLinkText("Server: ");
+        $e = $this->byPartialLinkText('Server: ');
         $e->click();
         $this->waitAjax();
     }
@@ -612,7 +612,7 @@ abstract class TestBase extends TestCase
     public function logOutIfLoggedIn()
     {
         if ($this->isLoggedIn()) {
-            $this->byCssSelector("img.icon.ic_s_loggoff")->click();
+            $this->byCssSelector('img.icon.ic_s_loggoff')->click();
         }
     }
 
@@ -716,8 +716,12 @@ abstract class TestBase extends TestCase
      */
     public function getCellByTableId($tableID, $row, $column)
     {
-        $sel = "table#{$tableID} tbody tr:nth-child({$row}) "
-            . "td:nth-child({$column})";
+        $sel = sprintf(
+            'table#%s tbody tr:nth-child(%d) td:nth-child(%d)',
+            $tableID,
+            $row,
+            $column
+        );
         $element = $this->byCssSelector(
             $sel
         );
@@ -737,8 +741,12 @@ abstract class TestBase extends TestCase
      */
     public function getCellByTableClass($tableClass, $row, $column)
     {
-        $sel = "table.{$tableClass} tbody tr:nth-child({$row}) "
-            . "td:nth-child({$column})";
+        $sel = sprintf(
+            'table.%s tbody tr:nth-child(%d) td:nth-child(%d)',
+            $tableClass,
+            $row,
+            $column
+        );
         $element = $this->byCssSelector(
             $sel
         );
@@ -820,7 +828,7 @@ abstract class TestBase extends TestCase
     {
         $this->waitForElement('cssSelector', 'div.cm-s-default');
         $this->webDriver->executeScript(
-            "$('.cm-s-default')[$index].CodeMirror.setValue('" . $text . "');"
+            "$('.cm-s-default')[" . $index . "].CodeMirror.setValue('" . $text . "');"
         );
     }
 
@@ -871,7 +879,7 @@ abstract class TestBase extends TestCase
         // go to table page
         $this->waitForElement(
             'xpath',
-            "//th//a[contains(., '$table')]"
+            "//th//a[contains(., '" . $table . "')]"
         )->click();
         $this->waitAjax();
 
@@ -1042,20 +1050,20 @@ abstract class TestBase extends TestCase
             curl_setopt(
                 $ch,
                 CURLOPT_URL,
-                $SESSION_REST_URL . $this->sessionId . ".json"
+                $SESSION_REST_URL . $this->sessionId . '.json'
             );
             curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
             curl_setopt($ch, CURLOPT_POSTFIELDS, $payload);
-            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PUT");
+            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'PUT');
             curl_setopt(
                 $ch,
                 CURLOPT_USERPWD,
                 $GLOBALS['TESTSUITE_BROWSERSTACK_USER']
-                    . ":" . $GLOBALS['TESTSUITE_BROWSERSTACK_KEY']
+                    . ':' . $GLOBALS['TESTSUITE_BROWSERSTACK_KEY']
             );
 
             $headers = [];
-            $headers[] = "Content-Type: application/json";
+            $headers[] = 'Content-Type: application/json';
             curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
 
             $result = curl_exec($ch);
@@ -1071,14 +1079,14 @@ abstract class TestBase extends TestCase
                 curl_setopt(
                     $ch,
                     CURLOPT_URL,
-                    $SESSION_REST_URL . $this->sessionId . ".json"
+                    $SESSION_REST_URL . $this->sessionId . '.json'
                 );
                 curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
                 curl_setopt(
                     $ch,
                     CURLOPT_USERPWD,
                     $GLOBALS['TESTSUITE_BROWSERSTACK_USER']
-                    . ":" . $GLOBALS['TESTSUITE_BROWSERSTACK_KEY']
+                    . ':' . $GLOBALS['TESTSUITE_BROWSERSTACK_KEY']
                 );
                 $result = curl_exec($ch);
                 $proj = json_decode($result);
diff --git a/test/selenium/TrackingTest.php b/test/selenium/TrackingTest.php
index 614854c64b..6c489c2a52 100644
--- a/test/selenium/TrackingTest.php
+++ b/test/selenium/TrackingTest.php
@@ -27,21 +27,21 @@ class TrackingTest extends TestBase
     {
         parent::setUp();
         $this->dbQuery(
-            "CREATE TABLE `test_table` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "CREATE TABLE `test_table_2` ("
-            . " `id` int(11) NOT NULL AUTO_INCREMENT,"
-            . " `val` int(11) NOT NULL,"
-            . " PRIMARY KEY (`id`)"
-            . ")"
+            'CREATE TABLE `test_table_2` ('
+            . ' `id` int(11) NOT NULL AUTO_INCREMENT,'
+            . ' `val` int(11) NOT NULL,'
+            . ' PRIMARY KEY (`id`)'
+            . ')'
         );
         $this->dbQuery(
-            "INSERT INTO `test_table` (val) VALUES (2), (3);"
+            'INSERT INTO `test_table` (val) VALUES (2), (3);'
         );
 
         $this->login();
@@ -50,16 +50,16 @@ class TrackingTest extends TestBase
         $this->navigateDatabase($this->database_name);
         $this->expandMore();
 
-        $this->waitForElement('partialLinkText', "Tracking")->click();
+        $this->waitForElement('partialLinkText', 'Tracking')->click();
         $this->waitAjax();
 
-        $this->waitForElement('partialLinkText', "Track table");
+        $this->waitForElement('partialLinkText', 'Track table');
         $this->byXPath("(//a[contains(., 'Track table')])[1]")->click();
 
         $this->waitAjax();
-        $this->waitForElement('name', "delete")->click();
+        $this->waitForElement('name', 'delete')->click();
         $this->byCssSelector("input[value='Create version']")->click();
-        $this->waitForElement('id', "versions");
+        $this->waitForElement('id', 'versions');
     }
 
     /**
@@ -73,35 +73,35 @@ class TrackingTest extends TestBase
     {
         $this->_executeSqlAndReturnToTableTracking();
 
-        $this->byPartialLinkText("Tracking report")->click();
+        $this->byPartialLinkText('Tracking report')->click();
         $this->waitForElement(
             'xpath',
             "//h3[contains(., 'Tracking report')]"
         );
 
         $this->assertStringContainsString(
-            "DROP TABLE IF EXISTS `test_table`",
+            'DROP TABLE IF EXISTS `test_table`',
             $this->getCellByTableId('ddl_versions', 1, 4)
         );
 
         $this->assertStringContainsString(
-            "CREATE TABLE `test_table` (",
+            'CREATE TABLE `test_table` (',
             $this->getCellByTableId('ddl_versions', 2, 4)
         );
 
         $this->assertStringContainsString(
-            "UPDATE test_table SET val = val + 1",
+            'UPDATE test_table SET val = val + 1',
             $this->getCellByTableId('dml_versions', 1, 4)
         );
 
         $this->assertStringNotContainsString(
-            "DELETE FROM test_table WHERE val = 3",
-            $this->byId("dml_versions")->getText()
+            'DELETE FROM test_table WHERE val = 3',
+            $this->byId('dml_versions')->getText()
         );
 
         // only structure
         $this->selectByLabel(
-            $this->byName("logtype"),
+            $this->byName('logtype'),
             'Structure only'
         );
 
@@ -110,22 +110,22 @@ class TrackingTest extends TestBase
         $this->waitAjax();
 
         $this->assertFalse(
-            $this->isElementPresent('id', "dml_versions")
+            $this->isElementPresent('id', 'dml_versions')
         );
 
         $this->assertStringContainsString(
-            "DROP TABLE IF EXISTS `test_table`",
+            'DROP TABLE IF EXISTS `test_table`',
             $this->getCellByTableId('ddl_versions', 1, 4)
         );
 
         $this->assertStringContainsString(
-            "CREATE TABLE `test_table` (",
+            'CREATE TABLE `test_table` (',
             $this->getCellByTableId('ddl_versions', 2, 4)
         );
 
         // only data
         $this->selectByLabel(
-            $this->waitForElement('name', "logtype"),
+            $this->waitForElement('name', 'logtype'),
             'Data only'
         );
 
@@ -134,17 +134,17 @@ class TrackingTest extends TestBase
         $this->waitAjax();
 
         $this->assertFalse(
-            $this->isElementPresent('id', "ddl_versions")
+            $this->isElementPresent('id', 'ddl_versions')
         );
 
         $this->assertStringContainsString(
-            "UPDATE test_table SET val = val + 1",
+            'UPDATE test_table SET val = val + 1',
             $this->getCellByTableId('dml_versions', 1, 4)
         );
 
         $this->assertStringNotContainsString(
-            "DELETE FROM test_table WHERE val = 3",
-            $this->byId("dml_versions")->getText()
+            'DELETE FROM test_table WHERE val = 3',
+            $this->byId('dml_versions')->getText()
         );
     }
 
@@ -164,7 +164,7 @@ class TrackingTest extends TestBase
         );
         $this->_executeSqlAndReturnToTableTracking();
         $this->assertFalse(
-            $this->isElementPresent('id', "dml_versions")
+            $this->isElementPresent('id', 'dml_versions')
         );
     }
 
@@ -180,10 +180,10 @@ class TrackingTest extends TestBase
         $this->navigateDatabase($this->database_name, true);
         $this->expandMore();
 
-        $this->byPartialLinkText("Tracking")->click();
+        $this->byPartialLinkText('Tracking')->click();
 
         $this->waitAjax();
-        $this->waitForElement('id', "versions");
+        $this->waitForElement('id', 'versions');
 
         $ele = $this->waitForElement(
             'cssSelector',
@@ -194,7 +194,7 @@ class TrackingTest extends TestBase
 
         $this->waitForElement(
             'cssSelector',
-            "button.submitOK"
+            'button.submitOK'
         )->click();
 
         $this->waitAjax();
@@ -231,26 +231,26 @@ class TrackingTest extends TestBase
      */
     public function testStructureSnapshot()
     {
-        $this->byPartialLinkText("Structure snapshot")->click();
-        $this->waitForElement('id', "tablestructure");
+        $this->byPartialLinkText('Structure snapshot')->click();
+        $this->waitForElement('id', 'tablestructure');
 
         $this->assertStringContainsString(
-            "id",
+            'id',
             $this->getCellByTableId('tablestructure', 1, 2)
         );
 
         $this->assertStringContainsString(
-            "val",
+            'val',
             $this->getCellByTableId('tablestructure', 2, 2)
         );
 
         $this->assertStringContainsString(
-            "PRIMARY",
+            'PRIMARY',
             $this->getCellByTableId('tablestructure_indexes', 1, 1)
         );
 
         $this->assertStringContainsString(
-            "id",
+            'id',
             $this->getCellByTableId('tablestructure_indexes', 1, 5)
         );
     }
@@ -262,22 +262,22 @@ class TrackingTest extends TestBase
      */
     private function _executeSqlAndReturnToTableTracking()
     {
-        $this->byPartialLinkText("SQL")->click();
+        $this->byPartialLinkText('SQL')->click();
         $this->waitAjax();
 
-        $this->waitForElement('id', "queryfieldscontainer");
+        $this->waitForElement('id', 'queryfieldscontainer');
         $this->typeInTextArea(
-            ";UPDATE test_table SET val = val + 1; "
-            . "DELETE FROM test_table WHERE val = 3"
+            ';UPDATE test_table SET val = val + 1; '
+            . 'DELETE FROM test_table WHERE val = 3'
         );
         $this->scrollToBottom();
         $this->byCssSelector("input[value='Go']")->click();
         $this->waitAjax();
-        $this->waitForElement('className', "alert-success");
+        $this->waitForElement('className', 'alert-success');
 
         $this->expandMore();
-        $this->byPartialLinkText("Tracking")->click();
+        $this->byPartialLinkText('Tracking')->click();
         $this->waitAjax();
-        $this->waitForElement('id', "versions");
+        $this->waitForElement('id', 'versions');
     }
 }
diff --git a/test/selenium/XssTest.php b/test/selenium/XssTest.php
index d5551051d0..77b5425d4c 100644
--- a/test/selenium/XssTest.php
+++ b/test/selenium/XssTest.php
@@ -39,11 +39,11 @@ class XssTest extends TestBase
         if ($this->isSafari()) {
             $this->markTestSkipped('Alerts not supported on Safari browser.');
         }
-        $this->waitForElement('partialLinkText', "SQL")->click();
+        $this->waitForElement('partialLinkText', 'SQL')->click();
         $this->waitAjax();
 
-        $this->waitForElement('id', "queryboxf");
-        $this->byId("button_submit_query")->click();
-        $this->assertEquals("Missing value in the form!", $this->alertText());
+        $this->waitForElement('id', 'queryboxf');
+        $this->byId('button_submit_query')->click();
+        $this->assertEquals('Missing value in the form!', $this->alertText());
     }
 }