以下两种都可以 ,你那样错了是因为from子句中的子查询不能和from子句中其他的表相关联select a.title,a.username,a.adddate from a,(select title,max(addddate) adddate from [table] group by title)bwhere b.title=a.titleselect title,username,(select max(addddate) adddate from [table] where [table].title=a.title)from a