居然要加这么多层，还需要在里面加一个别名才可以。

删除标题重复的旧记录。

delete from theTable where id in
(
	select id from 
	(
		select min(id) id from theTable group by title HAVING count(*)>1
	) ids
) ;

醉了，mysql的删除居然变得这么麻烦 delete from table where id in()