doctrine:migration:diff does not work if the table has an index with a functional part.

src/Driver/AbstractMySQLDriver.php

@@ -12,6 +12,7 @@
 use Doctrine\DBAL\Platforms\MariaDb1043Platform;
 use Doctrine\DBAL\Platforms\MariaDb1052Platform;
 use Doctrine\DBAL\Platforms\MySQL57Platform;
+use Doctrine\DBAL\Platforms\MySQL8013Platform;
 use Doctrine\DBAL\Platforms\MySQL80Platform;
 use Doctrine\DBAL\Platforms\MySQLPlatform;
 use Doctrine\DBAL\Schema\MySQLSchemaManager;
@@ -69,7 +70,11 @@ public function createDatabasePlatformForVersion($version)
                     );
                 }
 
-                return new MySQL80Platform();
+                if (version_compare($version, '8.0.13', '<')) {
+                    return new MySQL80Platform();
+                }
+
+                return new MySQL8013Platform();
             }
 
             if (version_compare($oracleMysqlVersion, '5.7.9', '>=')) {

src/Platforms/AbstractMySQLPlatform.php

@@ -50,6 +50,11 @@ abstract class AbstractMySQLPlatform extends AbstractPlatform
     public const LENGTH_LIMIT_BLOB       = 65535;
     public const LENGTH_LIMIT_MEDIUMBLOB = 16777215;
 
+    public function getColumnNameForIndexFetch(): string
+    {
+        return 'COLUMN_NAME';
+    }
+
     /**
      * {@inheritDoc}
      */

src/Platforms/AbstractPlatform.php

@@ -3225,6 +3225,8 @@ public function getCustomTypeDeclarationSQL(array $column)
      * declaration to be used in statements like CREATE TABLE.
      *
      * @deprecated
+     *
+     * @throws Exception If not supported on this platform.
      */
     public function getIndexFieldDeclarationListSQL(Index $index): string
     {
@@ -3235,6 +3237,10 @@ public function getIndexFieldDeclarationListSQL(Index $index): string
             __METHOD__,
         );
 
+        if ($index->isFunctional() && ! $this->supportsFunctionalIndex()) {
+            throw Exception::notSupported('Functional indexes');
+        }
+
         return implode(', ', $index->getQuotedColumns($this));
     }
 
@@ -4394,6 +4400,14 @@ public function supportsLimitOffset()
         return true;
     }
 
+    /**
+     * A flag that indicates whether the platform supports functional indexes.
+     */
+    public function supportsFunctionalIndex(): bool
+    {
+        return false;
+    }
+
     /**
      * Maximum length of any given database identifier, like tables or column names.
      *

src/Platforms/MySQL8013Platform.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Doctrine\DBAL\Platforms;
+
+/**
+ * Provides features of the MySQL since 8.0.13 database platform.
+ *
+ * Note: Should not be used with versions prior to 8.0.13.
+ */
+class MySQL8013Platform extends MySQL80Platform
+{
+    public function getColumnNameForIndexFetch(): string
+    {
+        return "COALESCE(COLUMN_NAME, CONCAT('(', REPLACE(EXPRESSION, '\\\''', ''''), ')'))";
+    }
+
+    public function supportsFunctionalIndex(): bool
+    {
+        return true;
+    }
+}

src/Platforms/OraclePlatform.php

@@ -1328,4 +1328,9 @@ public function createSchemaManager(Connection $connection): OracleSchemaManager
     {
         return new OracleSchemaManager($connection, $this);
     }
+
+    public function supportsFunctionalIndex(): bool
+    {
+        return true;
+    }
 }

src/Platforms/PostgreSQLPlatform.php

@@ -1399,4 +1399,9 @@ public function createSchemaManager(Connection $connection): PostgreSQLSchemaMan
     {
         return new PostgreSQLSchemaManager($connection, $this);
     }
+
+    public function supportsFunctionalIndex(): bool
+    {
+        return true;
+    }
 }

src/Platforms/SqlitePlatform.php

@@ -1482,4 +1482,9 @@ public function createSchemaManager(Connection $connection): SqliteSchemaManager
     {
         return new SqliteSchemaManager($connection, $this);
     }
+
+    public function supportsFunctionalIndex(): bool
+    {
+        return true;
+    }
 }

src/Schema/Index.php

@@ -12,6 +12,7 @@
 use function array_shift;
 use function count;
 use function strtolower;
+use function substr;
 
 class Index extends AbstractAsset implements Constraint
 {
@@ -29,6 +30,9 @@ class Index extends AbstractAsset implements Constraint
     /** @var bool */
     protected $_isPrimary = false;
 
+    /** @var bool */
+    protected $_isFunctional = false;
+
     /**
      * Platform specific flags for indexes.
      * array($flagName => true)
@@ -70,6 +74,10 @@ public function __construct(
 
         foreach ($columns as $column) {
             $this->_addColumn($column);
+
+            $this->_isFunctional = $this->_isFunctional === true
+                ? $this->_isFunctional
+                : self::isFunctionalIndex($column);
         }
 
         foreach ($flags as $flag) {
@@ -104,10 +112,14 @@ public function getQuotedColumns(AbstractPlatform $platform)
         foreach ($this->_columns as $column) {
             $length = array_shift($subParts);
 
-            $quotedColumn = $column->getQuotedName($platform);
+            if ($this->isFunctional()) {
+                $quotedColumn = $column->getName();
+            } else {
+                $quotedColumn = $column->getQuotedName($platform);
 
-            if ($length !== null) {
-                $quotedColumn .= '(' . $length . ')';
+                if ($length !== null) {
+                    $quotedColumn .= '(' . $length . ')';
+                }
             }
 
             $columns[] = $quotedColumn;
@@ -144,6 +156,11 @@ public function isPrimary()
         return $this->_isPrimary;
     }
 
+    public function isFunctional(): bool
+    {
+        return $this->_isFunctional;
+    }
+
     /**
      * @param string $name
      * @param int    $pos
@@ -334,6 +351,11 @@ public function getOptions()
         return $this->options;
     }
 
+    public static function isFunctionalIndex(string $name): bool
+    {
+        return $name[0] === '(' && substr($name, -1) === ')';
+    }
+
     /**
      * Return whether the two indexes have the same partial index
      */

src/Schema/MySQLSchemaManager.php

@@ -28,6 +28,7 @@
 /**
  * Schema manager for the MySQL RDBMS.
  *
+ * @template T of AbstractMySQLPlatform
  * @extends AbstractSchemaManager<AbstractMySQLPlatform>
  */
 class MySQLSchemaManager extends AbstractSchemaManager
@@ -485,10 +486,12 @@ protected function selectIndexColumns(string $databaseName, ?string $tableName =
             $sql .= ' TABLE_NAME,';
         }
 
-        $sql .= <<<'SQL'
+        $columnName = $this->getColumnNameForIndexFetch();
+
+        $sql .= <<<SQL
         NON_UNIQUE  AS Non_Unique,
         INDEX_NAME  AS Key_name,
-        COLUMN_NAME AS Column_Name,
+        {$columnName},
         SUB_PART    AS Sub_Part,
         INDEX_TYPE  AS Index_Type
 FROM information_schema.STATISTICS
@@ -619,4 +622,17 @@ private function parseCreateOptions(?string $string): array
 
         return $options;
     }
+
+    /**
+     * EXPRESSION
+     *
+     * MySQL 8.0.13 and higher supports functional key parts (see Functional Key Parts), which affects both
+     * the COLUMN_NAME and EXPRESSION columns:
+     * For a nonfunctional key part, COLUMN_NAME indicates the column indexed by the key part and EXPRESSION is NULL.
+     * For a functional key part, COLUMN_NAME column is NULL and EXPRESSION indicates the expression for the key part.
+     */
+    private function getColumnNameForIndexFetch(): string
+    {
+        return $this->_platform->getColumnNameForIndexFetch() . ' as Column_Name';
+    }
 }

src/Schema/Table.php

@@ -320,7 +320,7 @@ private function _createIndex(
         }
 
         foreach ($columnNames as $columnName) {
-            if (! $this->hasColumn($columnName)) {
+            if (! $this->hasColumn($columnName) && ! Index::isFunctionalIndex($columnName)) {
                 throw SchemaException::columnDoesNotExist($columnName, $this->_name);
             }
         }

tests/Driver/VersionAwarePlatformDriverTest.php

@@ -11,6 +11,7 @@
 use Doctrine\DBAL\Platforms\MariaDb1027Platform;
 use Doctrine\DBAL\Platforms\MariaDb1052Platform;
 use Doctrine\DBAL\Platforms\MySQL57Platform;
+use Doctrine\DBAL\Platforms\MySQL8013Platform;
 use Doctrine\DBAL\Platforms\MySQL80Platform;
 use Doctrine\DBAL\Platforms\MySQLPlatform;
 use Doctrine\DBAL\Platforms\PostgreSQL100Platform;
@@ -50,6 +51,8 @@ public static function mySQLVersionProvider(): array
             ['8', MySQL80Platform::class, 'https://github.com/doctrine/dbal/pull/5779', true],
             ['8.0', MySQL80Platform::class, 'https://github.com/doctrine/dbal/pull/5779', true],
             ['8.0.11', MySQL80Platform::class, 'https://github.com/doctrine/dbal/pull/5779', false],
+            ['8.0.13', MySQL8013Platform::class, 'https://github.com/doctrine/dbal/pull/5779', false],
+            ['8.0.14', MySQL8013Platform::class, 'https://github.com/doctrine/dbal/pull/5779', false],
             ['6', MySQL57Platform::class],
             ['10.0.15-MariaDB-1~wheezy', MySQLPlatform::class, 'https://github.com/doctrine/dbal/pull/5779', false],
             ['5.5.5-10.1.25-MariaDB', MySQLPlatform::class, 'https://github.com/doctrine/dbal/pull/5779', false],

tests/Functional/Schema/MySQLSchemaManagerTest.php

@@ -3,6 +3,7 @@
 namespace Doctrine\DBAL\Tests\Functional\Schema;
 
 use DateTime;
+use Doctrine\DBAL\Exception;
 use Doctrine\DBAL\Platforms\AbstractMySQLPlatform;
 use Doctrine\DBAL\Platforms\AbstractPlatform;
 use Doctrine\DBAL\Platforms\MariaDb1027Platform;
@@ -267,6 +268,37 @@ public function testColumnCharsetChange(): void
         );
     }
 
+    public function testCreateTableWithFunctionalIndex(): void
+    {
+        $tableName = 'table_with_functional_index';
+
+        if (! $this->connection->getDatabasePlatform()->supportsFunctionalIndex()) {
+            $this->expectException(Exception::class);
+        }
+
+        $table = new Table($tableName);
+        $table->addColumn('col_string', Types::STRING)
+            ->setLength(100)
+            ->setNotnull(true)
+            ->setPlatformOption('charset', 'utf8');
+
+        $table->addIndex(['(LENGTH(col_string))'], 'length_index');
+
+        $this->dropAndCreateTable($table);
+
+        if (! ($this->connection->getDatabasePlatform()->supportsFunctionalIndex())) {
+            return;
+        }
+
+        $schema = $this->schemaManager->introspectTable($tableName);
+        self::assertArrayHasKey('length_index', $schema->getIndexes());
+        self::assertTrue($schema->getIndexes()['length_index']->isFunctional());
+        self::assertEquals(
+            '(length(`col_string`))',
+            $schema->getIndexes()['length_index']->getColumns()[0],
+        );
+    }
+
     public function testColumnCollation(): void
     {
         $table = new Table('test_collation');

tests/Schema/Platforms/MySQL8013SchemaTest.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Doctrine\DBAL\Tests\Schema\Platforms;
+
+use Doctrine\DBAL\Exception;
+use Doctrine\DBAL\Platforms\MySQL8013Platform;
+use Doctrine\DBAL\Platforms\MySQL80Platform;
+use Doctrine\DBAL\Schema\Table;
+use PHPUnit\Framework\TestCase;
+
+class MySQL8013SchemaTest extends TestCase
+{
+    private MySQL80Platform $platformMysql;
+    private MySQL8013Platform $platformMysql8013;
+
+    protected function setUp(): void
+    {
+        $this->platformMysql8013 = new MySQL8013Platform();
+        $this->platformMysql     = new MySQL80Platform();
+    }
+
+    public function testGenerateFunctionalIndex(): void
+    {
+        $table = new Table('test');
+        $table->addColumn('foo_id', 'integer');
+        $table->addIndex(['foo_id', '(CAST(bar AS CHAR(10)))'], 'idx_foo_id');
+
+        $sqls = [];
+        foreach ($table->getIndexes() as $index) {
+            $sqls[] = $this->platformMysql8013->getCreateIndexSQL(
+                $index,
+                $table->getQuotedName($this->platformMysql8013),
+            );
+        }
+
+        self::assertEquals(
+            ['CREATE INDEX idx_foo_id ON test (foo_id, (CAST(bar AS CHAR(10))))'],
+            $sqls,
+        );
+    }
+
+    public function testGenerateFunctionalIndexWithError(): void
+    {
+        $table = new Table('test');
+        $table->addColumn('foo_id', 'integer');
+        $table->addIndex(['foo_id', '(CAST(bar AS CHAR(10)))'], 'idx_foo_id');
+
+        foreach ($table->getIndexes() as $index) {
+            $this->expectException(Exception::class);
+
+            $this->platformMysql->getCreateIndexSQL(
+                $index,
+                $table->getQuotedName($this->platformMysql),
+            );
+        }
+    }
+}