sql语句进行排序

[lgwinym]

数据库为MYSQL


table a :content_id(内容ID)
table b: content_id(内容),comment_id(评论id)
table c: prasieID（赞ID），comment_id(评论id)

得到某条内容的评论列表 并且根据赞的个数进行排列

[迪迦凹凸曼]

select comment_id,cnt from (
select b.comment_id,sum(prasieID) as cnt from b inner join c on b.comment_id=c.comment_id 
group by c.comment_id
where b.content_id=N'xxxxxx')
order by cnt  desc

[开着拖拉机泡妞]

select a.*,t.content_id(内容),t.total from a full join(
select b.content_id,count(c.prasieID) as total from b
full join c on b.comment_id=c.comment_id group by b.content_id)t
on a.content_id=t.content_id
order by total

[lyj0913]

select b.comment_id,count(*)as seq from b inner join c on b.comment_id=c.comment_id where b.content_id="值" group by b.comment_id order by seq desc

如果数据库不做优化的话，可以先把 where b.content_id="值" 条件一个子查询然后再 inner join c 表