public static function mysql($host, $database, $user, $password, $prefix = null)
    {
        if (is_null($prefix)) {
            $prefixing = 'false';
            $prefix = 'ysf';
        } else {
            $prefixing = 'true';
        }
        //
        $content = Database::set('mysql', $host, $database, $user, $password, $prefixing, $prefix);
        //
        file_put_contents(Application::$root.'config/database.php', $content, 0);
        //
        return true;
    }