如何避免循环查询

Question

嗨，我怎样才能避免这样的查询？

示例查询：

$sql = DB::getInstance()->prepare("SELECT tb_id1 FROM table1 WHERE duedate < ?");
$sql->execute(array($currentdate));
  if($sql->rowCount()){
     while($row = $sql->fetch(PDO::FETCH_ASSOC)){      

   $sql2 = DB::getInstance()->prepare("UPDATE table2 SET isOverdue = 1 WHERE tb_id2 = ?");
   $sql2->execute(array($row["tb_id1"]));


    }
 }

Answer 1

您可以使用 update with join，因此在 PHP

中不使用任何循环

update table2 t2
join table1 t1 on t1.tb_id1 = t2.tb_id2
set t2.isOverdue = 1 
where 
t1.duedate < ?

如何避免循环查询

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