一般group by 后面带多少个字段？
select UserID,max(CreateON) as CreateOn from 文章表
group by UserID


如果还要多个字段
应该在group by后面加不？
还是嵌套两个select?

[解决办法]
看你的语句可以试试

SQL code

--1select * from 文章表 a where not exists(select 1 from 文章表 where UserID=a.UserID and CreateON>a.CreateON)--2select * from 文章表 a where CreateON=(select max(CreateON) from 文章表 where UserID=a.UserID )