按连接表最大值选择仅行

本文介绍了按连接表最大值选择仅行的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我只想为u.classno，u.userno选择最大b.enddate的行.但这不起作用.

I want to select only the row which has max b.enddate for u.classno, u.userno. But it doesn't work.

select u.classno, u.userno, b.enddate from libUser u join book b on b.id = u.bookid group by u.classno, u.userno having b.enddate=max(b.enddate) //doesn't works

推荐答案

怎么了?

select u.classno, u.userno, MAX(b.enddate) from libUser u join book b on b.id = u.bookid group by u.classno, u.userno