laravel/framework · error · RuntimeException

This database driver does not support modifying columns.

Error message

This database driver does not support modifying columns.

What it means

Grammar::compileChange() throws RuntimeException on the base; all four shipped grammars override it. It compiles the SQL for a column-modify command ($table->...->change()). Reaching the base means the active grammar is the unimplemented base class - i.e. a custom driver that cannot emit ALTER TABLE ... MODIFY statements.

Solutions

Run modify-column migrations on sqlite/mysql/pgsql/sqlsrv.
Implement compileChange() in your custom grammar (it must return one or more ALTER statements appropriate to the engine).
Rewrite the migration to drop and recreate the column instead of using ->change() where the engine allows.

Example fix

// before - throws on a custom driver that lacks compileChange
Schema::table('users', function (Blueprint $t) {
    $t->string('email', 320)->change();
});

// after - raw ALTER for the unsupported engine
DB::connection('custom')->statement('ALTER TABLE users MODIFY email VARCHAR(320)');

Defensive patterns

Strategy: type-guard

Validate before calling

$grammar = Schema::getConnection()->getSchemaGrammar();
if (get_class($grammar) === \Illuminate\Database\Schema\Grammars\Grammar::class) {
    throw new \DomainException('Connection uses the base Grammar; ->change() is unsupported.');
}

Type guard

function supportsCompileChange(\Illuminate\Database\Schema\Grammars\Grammar $grammar): bool
{
    return (new \ReflectionMethod($grammar, 'compileChange'))
        ->getDeclaringClass()->getName() !== \Illuminate\Database\Schema\Grammars\Grammar::class;
}

Try / catch

try {
    Schema::table('users', fn ($t) => $t->string('email', 320)->change());
} catch (\RuntimeException $e) {
    if (str_contains($e->getMessage(), 'modifying columns')) {
        DB::statement('ALTER TABLE users MODIFY email VARCHAR(320)');
    } else {
        throw $e;
    }
}

Prevention

Run ->change() migrations only on sqlite/mysql/pgsql/sqlsrv.
Implement compileChange in any custom grammar.
For experimental engines, prefer drop+recreate column over ->change() in migrations.

When it happens

Trigger: Issuing $table->integer('foo')->change() (or any ->change() call) in a migration on a connection whose SchemaGrammar is the base Grammar. The Blueprint builds a change command, dispatches it to the grammar, and the base refuses.

Common situations: A custom driver whose grammar was scaffolded but compileChange was never written; a test that injects the base Grammar; running migrations against an experimental engine.

Related errors

AI-assisted analysis of laravel/framework@e0f6eb3518 (2026-08-11). Data as JSON: /api/errors/4a25b402ed274bd4. Report an issue: GitHub.

Appendix: source

Thrown at src/Illuminate/Database/Schema/Grammars/Grammar.php:212

        return sprintf('alter table %s rename column %s to %s',
            $this->wrapTable($blueprint),
            $this->wrap($command->from),
            $this->wrap($command->to)
        );
    }

    /**
     * Compile a change column command into a series of SQL statements.
     *
     * @param  \Illuminate\Database\Schema\Blueprint  $blueprint
     * @param  \Illuminate\Support\Fluent  $command
     * @return list<string>|string
     *
     * @throws \RuntimeException
     */
    public function compileChange(Blueprint $blueprint, Fluent $command)
    {
        throw new RuntimeException('This database driver does not support modifying columns.');
    }

    /**
     * Compile a fulltext index key command.
     *
     * @param  \Illuminate\Database\Schema\Blueprint  $blueprint
     * @param  \Illuminate\Support\Fluent  $command
     * @return string
     *
     * @throws \RuntimeException
     */
    public function compileFulltext(Blueprint $blueprint, Fluent $command)
    {
        throw new RuntimeException('This database driver does not support fulltext index creation.');
    }

    /**
     * Compile a drop fulltext index command.

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