Merge pull request #5414 from morozov/deprecate-innodb-only-fk

Deprecate ignoring foreign keys DDL on non-InnoDB MySQL

UPGRADE.md

@@ -13,6 +13,11 @@ awareness about deprecated code.
 The `AbstractPlatform::supportsForeignKeyConstraints()` method has been deprecated. All platforms should support
 foreign key constraints.
 
+## Deprecated `AbstractPlatform::supportsForeignKeyConstraints()`.
+
+Relying on the DBAL not generating DDL for foreign keys on MySQL engines other than InnoDB is deprecated.
+Define foreign key constraints only if they are necessary.
+
 ## Deprecated `AbstractPlatform` methods exposing quote characters.
 
 The `AbstractPlatform::getStringLiteralQuoteCharacter()` and `::getIdentifierQuoteCharacter()` methods

src/Platforms/AbstractMySQLPlatform.php

@@ -451,9 +451,18 @@ protected function _getCreateTableSQL($name, array $columns, array $options = []
         }
 
         // Propagate foreign key constraints only for InnoDB.
-        if (isset($options['foreignKeys']) && $engine === 'INNODB') {
-            foreach ($options['foreignKeys'] as $definition) {
-                $sql[] = $this->getCreateForeignKeySQL($definition, $name);
+        if (isset($options['foreignKeys'])) {
+            if ($engine === 'INNODB') {
+                foreach ($options['foreignKeys'] as $definition) {
+                    $sql[] = $this->getCreateForeignKeySQL($definition, $name);
+                }
+            } elseif (count($options['foreignKeys']) > 0) {
+                Deprecation::trigger(
+                    'doctrine/dbal',
+                    'https://github.com/doctrine/dbal/pulls/5414',
+                    'Relying on the DBAL not generating DDL for foreign keys on MySQL engines'
+                        . ' other than InnoDB is deprecated. Define foreign key constraints only if they are necessary.'
+                );
             }
         }