Changes by code review

src/Platforms/AbstractMySQLPlatform.php

@@ -50,9 +50,9 @@ abstract class AbstractMySQLPlatform extends AbstractPlatform
     public const LENGTH_LIMIT_BLOB       = 65535;
     public const LENGTH_LIMIT_MEDIUMBLOB = 16777215;
 
-    public function isSupportsFunctionalIndex(): bool
+    public function getColumnNameForIndexFetch(): string
     {
-        return false;
+        return 'COLUMN_NAME';
     }
 
     /**

src/Platforms/AbstractPlatform.php

@@ -396,11 +396,6 @@ abstract public function getBlobTypeDeclarationSQL(array $column);
      */
     abstract public function getName();
 
-    /**
-     * A flag that indicates whether the platform supports functional indexes.
-     */
-    abstract public function isSupportsFunctionalIndex(): bool;
-
     /**
      * Registers a doctrine type to be used in conjunction with a column type of this platform.
      *
@@ -3242,7 +3237,7 @@ public function getIndexFieldDeclarationListSQL(Index $index): string
             __METHOD__,
         );
 
-        if ($index->isFunctional() && ! $this->isSupportsFunctionalIndex()) {
+        if ($index->isFunctional() && ! $this->supportsFunctionalIndex()) {
             throw Exception::notSupported('Functional indexes');
         }
 
@@ -4684,4 +4679,12 @@ public function createSchemaManager(Connection $connection): AbstractSchemaManag
     {
         throw Exception::notSupported(__METHOD__);
     }
+
+    /**
+     * A flag that indicates whether the platform supports functional indexes.
+     */
+    protected function supportsFunctionalIndex(): bool
+    {
+        return false;
+    }
 }

src/Platforms/DB2Platform.php

@@ -47,11 +47,6 @@ class DB2Platform extends AbstractPlatform
     /** @see https://www.ibm.com/docs/en/db2-for-zos/11?topic=tables-systables */
     private const SYSIBM_SYSTABLES_TYPE_TABLE = 'T';
 
-    public function isSupportsFunctionalIndex(): bool
-    {
-        return false;
-    }
-
     /**
      * {@inheritDoc}
      *

src/Platforms/MySQL8013Platform.php

@@ -6,13 +6,15 @@
  * Provides features of the MySQL since 8.0.13 database platform.
  *
  * Note: Should not be used with versions prior to 8.0.13.
- *
- * This class will be merged with {@see MySQLPlatform} when support for MySQL
- * releases prior to 8.0.13 will be dropped.
  */
 class MySQL8013Platform extends MySQL80Platform
 {
-    public function isSupportsFunctionalIndex(): bool
+    public function getColumnNameForIndexFetch(): string
+    {
+        return "COALESCE(COLUMN_NAME, concat('(', EXPRESSION, ')'))";
+    }
+
+    protected function supportsFunctionalIndex(): bool
     {
         return true;
     }

src/Platforms/OraclePlatform.php

@@ -55,11 +55,6 @@ public static function assertValidIdentifier($identifier)
         }
     }
 
-    public function isSupportsFunctionalIndex(): bool
-    {
-        return true;
-    }
-
     /**
      * {@inheritDoc}
      */
@@ -1333,4 +1328,9 @@ public function createSchemaManager(Connection $connection): OracleSchemaManager
     {
         return new OracleSchemaManager($connection, $this);
     }
+
+    protected function supportsFunctionalIndex(): bool
+    {
+        return true;
+    }
 }

src/Platforms/PostgreSQLPlatform.php

@@ -62,11 +62,6 @@ class PostgreSQLPlatform extends AbstractPlatform
         ],
     ];
 
-    public function isSupportsFunctionalIndex(): bool
-    {
-        return true;
-    }
-
     /**
      * PostgreSQL has different behavior with some drivers
      * with regard to how booleans have to be handled.
@@ -1404,4 +1399,9 @@ public function createSchemaManager(Connection $connection): PostgreSQLSchemaMan
     {
         return new PostgreSQLSchemaManager($connection, $this);
     }
+
+    protected function supportsFunctionalIndex(): bool
+    {
+        return true;
+    }
 }

src/Platforms/SQLServerPlatform.php

@@ -49,11 +49,6 @@
  */
 class SQLServerPlatform extends AbstractPlatform
 {
-    public function isSupportsFunctionalIndex(): bool
-    {
-        return false;
-    }
-
     /**
      * {@inheritDoc}
      */

src/Platforms/SqlitePlatform.php

@@ -45,11 +45,6 @@ class SqlitePlatform extends AbstractPlatform
 {
     private bool $schemaEmulationEnabled = true;
 
-    public function isSupportsFunctionalIndex(): bool
-    {
-        return true;
-    }
-
     /**
      * {@inheritDoc}
      */
@@ -1487,4 +1482,9 @@ public function createSchemaManager(Connection $connection): SqliteSchemaManager
     {
         return new SqliteSchemaManager($connection, $this);
     }
+
+    protected function supportsFunctionalIndex(): bool
+    {
+        return true;
+    }
 }

src/Schema/MySQLSchemaManager.php

@@ -7,7 +7,6 @@
 use Doctrine\DBAL\Platforms\MySQL;
 use Doctrine\DBAL\Platforms\MySQL\CollationMetadataProvider\CachingCollationMetadataProvider;
 use Doctrine\DBAL\Platforms\MySQL\CollationMetadataProvider\ConnectionCollationMetadataProvider;
-use Doctrine\DBAL\Platforms\MySQL8013Platform;
 use Doctrine\DBAL\Result;
 use Doctrine\DBAL\Types\Type;
 use Doctrine\Deprecations\Deprecation;
@@ -29,6 +28,7 @@
 /**
  * Schema manager for the MySQL RDBMS.
  *
+ * @template T of AbstractMySQLPlatform
  * @extends AbstractSchemaManager<AbstractMySQLPlatform>
  */
 class MySQLSchemaManager extends AbstractSchemaManager
@@ -633,10 +633,6 @@ private function parseCreateOptions(?string $string): array
      */
     private function getColumnNameForIndexFetch(): string
     {
-        if ($this->_platform instanceof MySQL8013Platform) {
-            return "COALESCE(COLUMN_NAME, concat('(', EXPRESSION, ')')) AS Column_Name";
-        }
-
-        return 'COLUMN_NAME as Column_Name';
+        return $this->_platform->getColumnNameForIndexFetch() . ' as Column_Name';
     }
 }