求解答下面的sql查询语句

if($machineName=="Picoline4S"){
$sql = "SELECT *,b.id as id_imp FROM rmts.operatedata b
left join rmts.code_imp a on a.machineName = b.machineName
left join (SELECT machineName,GROUP_CONCAT(tapeNo,'||',allName_final) AS txt FROM rmts.tapetotal where statu = '使用中' group by machineName) c on c.machineName = a.name_1
where b.machineName='$machineName' AND b.no_endTime='' and b.id=(select max(id) from rmts.operatedata where machineName='$machineName')";
}