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 r.cid,count(r.id) pv,sum(timestampdiff(minute,start_time,end_time)) as time_len from play_record_tb r left join course_info_tb i on r.cid = i.cid where start_time < date_add(release_date,interval 7 day) group by cid having avg(score) >= 3 order by pv desc,time_len desc limit 3
