protected function getForeignKeyCheck($enable = true)
    {
        $default = Config::get('database.default');
        switch ($default) {
            case 'sqlite':
                $string = 'PRAGMA foreign_keys = ' . ($enable ? 'ON' : 'OFF');
                break;
            default:
                $string = 'SET FOREIGN_KEY_CHECKS = ' . ($enable ? '1' : '0');
                break;
         }
        return $string;
    }