Fix for #12557

CHANGELOG.md

@@ -17,6 +17,7 @@
 - Fixed a bug where accessing a custom field’s magic property on an element would return the field’s raw database value rather than `null`, if it didn’t belong to the element’s field layout anymore. ([#12539](https://github.com/craftcms/cms/issues/12539), [#12578](https://github.com/craftcms/cms/pull/12578))
 - Fixed a bug where `craft\image\Raster::getIsTransparent()` wasn’t working. ([#12565](https://github.com/craftcms/cms/issues/12565))
 - Fixed a bug where the component name comments in project config YAML files would always lag behind the current project config a little. ([#12576](https://github.com/craftcms/cms/issues/12576), ([#12581](https://github.com/craftcms/cms/pull/12581)))
+- Fixed a MySQL error that occurred when creating a database backup using the default backup command, when running MySQL 5.7.41+ or 8.0.32+. ([#12557](https://github.com/craftcms/cms/issues/12557), [#12560](https://github.com/craftcms/cms/pull/12560))
 - Added `craft\helpers\Db::escapeForLike()`.
 - `craft\services\Assets::getAllDescendantFolders()` now has a `$withParent` argument, which can be passed `false` to omit the parent folder from the results. ([#12536](https://github.com/craftcms/cms/issues/12536))
 - Deprecated `craft\helpers\DateTimeHelper::timeZoneAbbreviation()`.

src/db/mysql/Schema.php

@@ -150,6 +150,18 @@ public function createColumnSchemaBuilder($type, $length = null)
      */
     public function getDefaultBackupCommand(array $ignoreTables = null): string
     {
+        $useSingleTransaction = true;
+        $serverVersion = App::normalizeVersion(Craft::$app->getDb()->getSchema()->getServerVersion());
+
+        $isMySQL5 = version_compare($serverVersion, '8', '<');
+        $isMySQL8 = version_compare($serverVersion, '8', '>=');
+
+        // https://bugs.mysql.com/bug.php?id=109685
+        if (($isMySQL5 && version_compare($serverVersion, '5.7.41', '>=')) ||
+            ($isMySQL8 && version_compare($serverVersion, '8.0.32', '>='))) {
+            $useSingleTransaction = false;
+        }
+
         $defaultArgs =
             ' --defaults-extra-file="' . $this->_createDumpConfigFile() . '"' .
             ' --add-drop-table' .
@@ -163,8 +175,12 @@ public function getDefaultBackupCommand(array $ignoreTables = null): string
             ' --triggers' .
             ' --no-tablespaces';
 
+        if ($useSingleTransaction) {
+            $defaultArgs .= ' --single-transaction';
+        }
+
         // If the server is MySQL 5.x, we need to see what version of mysqldump is installed (5.x or 8.x)
-        if (version_compare(App::normalizeVersion(Craft::$app->getDb()->getSchema()->getServerVersion()), "8", "<")) {
+        if ($isMySQL5) {
             // Find out if the db supports column-statistics
             $shellCommand = new ShellCommand();
 
@@ -198,7 +214,6 @@ public function getDefaultBackupCommand(array $ignoreTables = null): string
 
         $schemaDump = 'mysqldump' .
             $defaultArgs .
-            ' --single-transaction' .
             ' --no-data' .
             ' --result-file="{file}"' .
             ' {database}';