zyp00793的博客

例子：给出一个数据表，按name分组查询create_time最新的数据。有三种方法：1、order by之后再分组select * from (select * from user order by create_time desc limit 10000) a group by name结果为：注：（1）如果去掉limit限制查询不到最新的一条数据，因为子查询的排序为无效的；select * from (select * from user order by create_time d