laravel/framework · error · RuntimeException

This database driver does not support retrieving foreign…

Error message

This database driver does not support retrieving foreign keys.

What it means

Grammar::compileForeignKeys() throws RuntimeException on the base class; all four shipped grammars override it. Reaching the base means the connection's SchemaGrammar is the unimplemented base Grammar. Builder::getForeignKeys() routes here.

Solutions

Use a supported driver (sqlite/mysql/pgsql/sqlsrv) for foreign-key introspection.
Override compileForeignKeys($schema, $table) in your custom grammar.
Query information_schema.table_constraints / pg_constraint directly.

Example fix

// before
$fks = Schema::connection('custom')->getForeignKeys('orders');

// after
$fks = DB::connection('custom')->select(
    "SELECT constraint_name FROM information_schema.table_constraints WHERE table_name = ? AND constraint_type = 'FOREIGN KEY'",
    ['orders']
);

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; cannot list foreign keys.');
}

Type guard

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

Try / catch

try {
    $fks = Schema::getForeignKeys('orders');
} catch (\RuntimeException $e) {
    if (str_contains($e->getMessage(), 'retrieving foreign keys')) {
        $fks = DB::select("SELECT * FROM information_schema.table_constraints WHERE table_name = ? AND constraint_type = 'FOREIGN KEY'", ['orders']);
    } else {
        throw $e;
    }
}

Prevention

Bind a real grammar in custom connections; never ship the base Grammar.
Implement compileForeignKeys when authoring a new grammar.
In admin tooling, gate foreign-key introspection on the grammar class.

When it happens

Trigger: Schema::getForeignKeys($table) on a connection whose SchemaGrammar is the base Grammar (custom driver not implementing the method).

Common situations: Custom/community driver whose grammar was never filled in; an introspection/admin tool that calls getForeignKeys on every configured connection.

Related errors

AI-assisted analysis of laravel/framework@e0f6eb3518 (2026-08-11). Data as JSON: /api/errors/3633cb68e9e4ba63. Report an issue: GitHub.

Appendix: source

Thrown at src/Illuminate/Database/Schema/Grammars/Grammar.php:182

     * @throws \RuntimeException
     */
    public function compileVectorIndex(Blueprint $blueprint, Fluent $command)
    {
        throw new RuntimeException('The database driver in use does not support vector indexes.');
    }

    /**
     * Compile the query to determine the foreign keys.
     *
     * @param  string|null  $schema
     * @param  string  $table
     * @return string
     *
     * @throws \RuntimeException
     */
    public function compileForeignKeys($schema, $table)
    {
        throw new RuntimeException('This database driver does not support retrieving foreign keys.');
    }

    /**
     * Compile a rename column command.
     *
     * @param  \Illuminate\Database\Schema\Blueprint  $blueprint
     * @param  \Illuminate\Support\Fluent  $command
     * @return list<string>|string
     */
    public function compileRenameColumn(Blueprint $blueprint, Fluent $command)
    {
        return sprintf('alter table %s rename column %s to %s',
            $this->wrapTable($blueprint),
            $this->wrap($command->from),
            $this->wrap($command->to)
        );
    }

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