题解 | 最受欢迎的top3课程
最受欢迎的top3课程
https://www.nowcoder.com/practice/b9b33659559c46099aa3257da0374a48
select a.cid,count(1) as pv,round(sum(timestampdiff(minute,start_time,end_time)),3) as time_len from play_record_tb a left join course_info_tb b using(cid) where datediff(start_time,release_date)<7 group by a.cid having avg(score)>=3 order by pv desc, time_len desc limit 3
