- select a.* from zeai_photo a inner join (select max(id) mid,userid from zeai_photo group by userid) b on a.userid = b.userid and a.id = b.mid order by a.userid
- 参考：http://www.cnblogs.com/netserver/p/4518995.html
group by的运用
原文：https://www.cnblogs.com/qq1069284034/p/9603655.html
