function table($str)    {        /*        if($str==‘goods‘){            return ‘`ecshop3‘ . ‘`.`‘ . $this->prefix . $str . ‘`‘;        }        else{            return ‘`‘ . $this->db_name . ‘`.`‘ . $this->prefix . $str . ‘`‘;        }        */        return ‘`‘ . $this->db_name . ‘`.`‘ . $this->prefix . $str . ‘`‘;    }