【大厂真题】SQL28题解 | 被重复观看次数最多的3个视频
SELECT cid,pv,rk
from (
select a.cid,sum(nums) as pv,
ROW_NUMBER() OVER(order by sum(nums) desc,a.release_date desc) as rk ###排名问题
from course_info_tb a
inner join
(
select cid,uid,count(*) nums
from
play_record_tb
group by cid,uid
having count(*)>1
) b
on a.cid=b.cid
group by a.cid,a.release_date
) t
where rk<=3
order by rk asc
注意分区，不要加
limit 3也可以
