MySQL 报错 1093

[Err] 1093 - You can't specify target table 'user' for update in FROM clause

报错的sql如下:

delete from `user` where id not in (select min(id) as id from `user` group by name );

报错的原因是：不能先select出同一表中的某些值，再update这个表(在同一语句中)。

改成下面这样就好了（将查出的数据再通过中间表查一遍）：

delete from `user` where id not in (
　　select id from(
　　　　select min(id) as id from `user` group by name
　　) id

);