只需合并2删除查询即可

Question

我有2个删除SQL查询我想让它成为一个。

$sql1= DELETE FROM user WHERE userid={$id}

另一个是

$sql = Delete FROM user_meta where userid = {$id}

有什么建议吗？我想简单化。

Answer 1

您无法从DELETE语句中的2个表中删除，但是您在1个中发出2个语句：

$sql = "DELETE FROM user WHERE userid={$id};
DELETE FROM user_meta WHERE meta_key = {$id};"

Answer 2

“同时”从不同表中删除内容的正常方法是将它们包装在事务中。类似的东西：

begin transaction thedeletes
    DELETE FROM user WHERE userid={$id};
    DELETE FROM user_meta WHERE userid = {$id}
commit transaction thedeletes;

在MySQL中，您实际上可以将它们放在同一个查询中：

delete u, um
    from user u join
         user_meta um
         on u.userid={$id} and um.userid = {$id};