mysql报错 You can‘t specify target table XXX for update in FROM clause

交表删除

mysql> delete from post_users where id in (
    -> select u.id from post_users u 
    -> left join posts s on u.post_id = s.id 
    -> where s.id is null) ;

报错提示：

ERROR 1093 (HY000): You can't specify target table 'dz_users' for update in FROM clause

问题根源，不能直接这样，必须中间临时表。

解决办法：

delete from post_users where id in (
select id from (
		select distinct u.id from post_users u 
		left join posts s on u.post_id = s.id 
		where s.id is null
	) m 
)