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 . ‘`‘;
    }