Implement an EnumType for MySQL/MariaDB

docs/en/reference/types.rst

@@ -196,6 +196,16 @@ type natively, this type is mapped to the ``string`` type internally.
 Values retrieved from the database are always converted to PHP's ``string`` type
 or ``null`` if no data is present.
 
+enum
+++++
+
+Maps and converts a string which is one of a set of predefined values. This
+type is specifically designed for MySQL and MariaDB, where it is mapped to
+the native ``ENUM`` type. For other database vendors, this type is mapped to
+a string field (``VARCHAR``) with the maximum length being the length of the
+longest value in the set. Values retrieved from the database are always
+converted to PHP's ``string`` type or ``null`` if no data is present.
+
 Binary string types
 ^^^^^^^^^^^^^^^^^^^
 

src/Exception/InvalidColumnType/ColumnValuesRequired.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\DBAL\Exception\InvalidColumnType;
+
+use Doctrine\DBAL\Exception\InvalidColumnType;
+use Doctrine\DBAL\Platforms\AbstractPlatform;
+
+use function get_debug_type;
+use function sprintf;
+
+/** @psalm-immutable */
+final class ColumnValuesRequired extends InvalidColumnType
+{
+    /**
+     * @param AbstractPlatform $platform The target platform
+     * @param string           $type     The SQL column type
+     */
+    public static function new(AbstractPlatform $platform, string $type): self
+    {
+        return new self(
+            sprintf(
+                '%s requires the values of a %s column to be specified',
+                get_debug_type($platform),
+                $type,
+            ),
+        );
+    }
+}

src/Platforms/AbstractMySQLPlatform.php

@@ -6,6 +6,7 @@
 
 use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\Exception;
+use Doctrine\DBAL\Exception\InvalidColumnType\ColumnValuesRequired;
 use Doctrine\DBAL\Platforms\Keywords\KeywordList;
 use Doctrine\DBAL\Platforms\Keywords\MySQLKeywords;
 use Doctrine\DBAL\Schema\AbstractAsset;
@@ -18,12 +19,14 @@
 use Doctrine\DBAL\TransactionIsolationLevel;
 use Doctrine\DBAL\Types\Types;
 
+use function array_map;
 use function array_merge;
 use function array_unique;
 use function array_values;
 use function count;
 use function implode;
 use function in_array;
+use function is_array;
 use function is_numeric;
 use function sprintf;
 use function str_replace;
@@ -645,6 +648,21 @@
         return parent::getDecimalTypeDeclarationSQL($column) . $this->getUnsignedDeclaration($column);
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function getEnumDeclarationSQL(array $column): string
+    {
+        if (! isset($column['values']) || ! is_array($column['values']) || $column['values'] === []) {
+            throw ColumnValuesRequired::new($this, 'ENUM');
+        }
+
+        return sprintf('ENUM(%s)', implode(', ', array_map(
+            $this->quoteStringLiteral(...),
+            $column['values'],
+        )));
+    }
+
     /**
      * Get unsigned declaration for a column.
      *
@@ -718,6 +736,7 @@
             'datetime'   => Types::DATETIME_MUTABLE,
             'decimal'    => Types::DECIMAL,
             'double'     => Types::FLOAT,
+            'enum'       => Types::ENUM,
             'float'      => Types::SMALLFLOAT,
             'int'        => Types::INTEGER,
             'integer'    => Types::INTEGER,

src/Platforms/AbstractPlatform.php

@@ -12,6 +12,7 @@
 use Doctrine\DBAL\Exception\InvalidColumnType\ColumnLengthRequired;
 use Doctrine\DBAL\Exception\InvalidColumnType\ColumnPrecisionRequired;
 use Doctrine\DBAL\Exception\InvalidColumnType\ColumnScaleRequired;
+use Doctrine\DBAL\Exception\InvalidColumnType\ColumnValuesRequired;
 use Doctrine\DBAL\LockMode;
 use Doctrine\DBAL\Platforms\Exception\NoColumnsSpecifiedForTable;
 use Doctrine\DBAL\Platforms\Exception\NotSupported;
@@ -51,6 +52,8 @@
 use function is_float;
 use function is_int;
 use function is_string;
+use function max;
+use function mb_strlen;
 use function preg_quote;
 use function preg_replace;
 use function sprintf;
@@ -190,6 +193,25 @@ public function getBinaryTypeDeclarationSQL(array $column): string
         }
     }
 
+    /**
+     * Returns the SQL snippet to declare an ENUM column.
+     *
+     * Enum is a non-standard type that is especially popular in MySQL and MariaDB. By default, this method map to
+     * a simple VARCHAR field which allows us to deploy it on any platform, e.g. SQLite.
+     *
+     * @param array<string, mixed> $column
+     *
+     * @throws ColumnValuesRequired If the column definition does not contain any values.
+     */
+    public function getEnumDeclarationSQL(array $column): string
+    {
+        if (! isset($column['values']) || ! is_array($column['values']) || $column['values'] === []) {
+            throw ColumnValuesRequired::new($this, 'ENUM');
+        }
+
+        return $this->getStringTypeDeclarationSQL(['length' => max(...array_map(mb_strlen(...), $column['values']))]);
+    }
+
     /**
      * Returns the SQL snippet to declare a GUID/UUID column.
      *

src/Schema/Column.php

@@ -33,6 +33,9 @@
 
     protected bool $_autoincrement = false;
 
+    /** @var list<string> */
+    protected array $_values = [];
+
     /** @var array<string, mixed> */
     protected array $_platformOptions = [];
 
@@ -231,22 +234,41 @@
         return $this->_comment;
     }
 
+    /**
+     * @param list<string> $values
+     *
+     * @return $this
+     */
+    public function setValues(array $values): static
+    {
+        $this->_values = $values;
+
+        return $this;
+    }
+
+    /** @return list<string> */
+    public function getValues(): array
+    {
+        return $this->_values;
+    }
+
     /** @return array<string, mixed> */
     public function toArray(): array
     {
         return array_merge([
-            'name'          => $this->_name,
-            'type'          => $this->_type,
-            'default'       => $this->_default,
-            'notnull'       => $this->_notnull,
-            'length'        => $this->_length,
-            'precision'     => $this->_precision,
-            'scale'         => $this->_scale,
-            'fixed'         => $this->_fixed,
-            'unsigned'      => $this->_unsigned,
-            'autoincrement' => $this->_autoincrement,
+            'name'             => $this->_name,
+            'type'             => $this->_type,
+            'default'          => $this->_default,
+            'notnull'          => $this->_notnull,
+            'length'           => $this->_length,
+            'precision'        => $this->_precision,
+            'scale'            => $this->_scale,
+            'fixed'            => $this->_fixed,
+            'unsigned'         => $this->_unsigned,
+            'autoincrement'    => $this->_autoincrement,
             'columnDefinition' => $this->_columnDefinition,
-            'comment' => $this->_comment,
+            'comment'          => $this->_comment,
+            'values'           => $this->_values,
         ], $this->_platformOptions);
     }
 }

src/Schema/MySQLSchemaManager.php

@@ -17,11 +17,13 @@
 use Doctrine\DBAL\Types\Type;
 
 use function array_change_key_case;
+use function array_map;
 use function assert;
 use function explode;
 use function implode;
 use function is_string;
 use function preg_match;
+use function preg_match_all;
 use function str_contains;
 use function strtok;
 use function strtolower;
@@ -134,6 +136,8 @@
 
         $type = $this->platform->getDoctrineTypeMapping($dbType);
 
+        $values = [];
+
         switch ($dbType) {
             case 'char':
             case 'binary':
@@ -192,6 +196,10 @@
             case 'year':
                 $length = null;
                 break;
+
+            case 'enum':
+                $values = $this->parseEnumExpression($tableColumn['type']);
+                break;
         }
 
         if ($this->platform instanceof MariaDBPlatform) {
@@ -209,6 +217,7 @@
             'scale'         => $scale,
             'precision'     => $precision,
             'autoincrement' => str_contains($tableColumn['extra'], 'auto_increment'),
+            'values'        => $values,
         ];
 
         if (isset($tableColumn['comment'])) {
@@ -228,6 +237,18 @@
         return $column;
     }
 
+    /** @return list<string> */
+    private function parseEnumExpression(string $expression): array
+    {
+        $result = preg_match_all("/'([^']*(?:''[^']*)*)'/", $expression, $matches);
+        assert($result !== false);
+
+        return array_map(
+            static fn (string $match): string => strtr($match, ["''" => "'"]),
+            $matches[1],
+        );
+    }
+
     /**
      * Return Doctrine/Mysql-compatible column default values for MariaDB 10.2.7+ servers.
      *

src/Types/EnumType.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\DBAL\Types;
+
+use Doctrine\DBAL\Platforms\AbstractPlatform;
+
+final class EnumType extends Type
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function getSQLDeclaration(array $column, AbstractPlatform $platform): string
+    {
+        return $platform->getEnumDeclarationSQL($column);
+    }
+}

src/Types/Type.php

@@ -34,6 +34,7 @@ abstract class Type
         Types::DATETIMETZ_MUTABLE   => DateTimeTzType::class,
         Types::DATETIMETZ_IMMUTABLE => DateTimeTzImmutableType::class,
         Types::DECIMAL              => DecimalType::class,
+        Types::ENUM                 => EnumType::class,
         Types::FLOAT                => FloatType::class,
         Types::GUID                 => GuidType::class,
         Types::INTEGER              => IntegerType::class,

src/Types/Types.php

@@ -23,6 +23,7 @@ final class Types
     public const DATETIMETZ_IMMUTABLE = 'datetimetz_immutable';
     public const DECIMAL              = 'decimal';
     public const FLOAT                = 'float';
+    public const ENUM                 = 'enum';
     public const GUID                 = 'guid';
     public const INTEGER              = 'integer';
     public const JSON                 = 'json';

tests/Functional/Schema/MySQLSchemaManagerTest.php

@@ -561,7 +561,10 @@ public function testColumnIntrospection(): void
         $doctrineTypes = array_keys(Type::getTypesMap());
 
         foreach ($doctrineTypes as $type) {
-            $table->addColumn('col_' . $type, $type, ['length' => 8, 'precision' => 8, 'scale' => 2]);
+            $table->addColumn('col_' . $type, $type, match ($type) {
+                Types::ENUM => ['values' => ['foo', 'bar']],
+                default => ['length' => 8, 'precision' => 8, 'scale' => 2],
+            });
         }
 
         $this->dropAndCreateTable($table);