今天以前的同学问我关于这方面的SQL语句,我特意记忆一下,毕竟这个也比较常见了 代码如下: select * from (select * from member_payment order by id desc) t group by member_id limit 10 第一种是先排序,然后group,这样的话自然可以取到最适合的一条数据。 缺点很明显:Using temporary; Using filesort 代码如下: select s.* from (SELECT max(id) as id FROM member_payment group by member_id limit 10) t left join member_payment as s on t.id=s.id 第二种是联合查询 代码如下: select * from member_payment where EXISTS ( select id from ( SELECT max(id) as id FROM member_payment group by member_id limit 10) t where t.id=member_payment.id ) 第三种是子查询 窃以为第二种效率最高 from:http://www.jb51.net/article/39369.htm 没看到第三种实现~~
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