查询不重复的用户名的最新信息
1.select tt.* from(
select * from comments order by theTime desc) as tt group by newsID
2.select * from comments as tt group by id,newsID,comment,theTime having
theTime=(select max(theTime) from comments where newsID=tt.newsID)
1.select tt.* from(
select * from comments order by theTime desc) as tt group by newsID
2.select * from comments as tt group by id,newsID,comment,theTime having
theTime=(select max(theTime) from comments where newsID=tt.newsID)