子查询在mysql中失败

Question

I have a subquery as follows : which will select the id's according to the condition first and delete 我有一个子查询，如下所示：它将首先根据条件选择ID并删除

the records , 记录，

    Delete from post_master_user_map WHERE id IN
(SELECT id FROM `post_master_user_map` WHERE posted_by_user_id=110);

But it gives me the following error : 但这给了我以下错误：

You can't specify target table 'post_master_user_map' for update in FROM clause

What is wrong with this ? 这有什么问题？ thanks in advance . 提前致谢。

UPDATE UPDATE

This also fails , I dont why 这也失败了，我不为什么

DELETE FROM `post_master_user_map` WHERE `reshare_id` in (SELECT id FROM `post_master_user_map` WHERE 
posted_by_user_id=110);

Answer 1

This error occurs when you try to modify a table and select from the same table in sub query. 当您尝试修改表并在子查询中从同一表中选择时，会发生此错误。

Anyway to solve that error change your query as follows 无论如何要解决该错误，请按以下方式更改查询

Delete from post_master_user_map WHERE posted_by_user_id=110;

For the updated query(in your question) use following 对于更新的查询（在您的问题中），请使用以下命令

    DELETE t1 FROM post_master_user_map as t1 INNER JOIN 
post_master_user_map as t2 ON t1.reshare_id=t2.id and t2.posted_by_user_id=110

Answer 2

通过此MySQL DELETE FROM以子查询为条件：MySQL不允许在条件的子查询中使用要删除的表。