public static function update()
    {
        $result = null;

        switch (static::getDriver()) {
            case self::DRIVER_MYSQL:
                $result = new \pwf\components\querybuilder\adapters\MySQL\UpdateBuilder();
                break;
            case self::DRIVER_PG:
                $result = new \pwf\components\querybuilder\adapters\PostgreSQL\UpdateBuilder();
                break;
            default:
                throw new \Exception('Wrong query builder driver');
        }

        return $result;
    }