题解 | 最受欢迎的top3课程
最受欢迎的top3课程
https://www.nowcoder.com/practice/b9b33659559c46099aa3257da0374a48
with t1 as(select uid, a.cid cid, timestampdiff(minute,start_time,end_time) time_len, score from course_info_tb a inner join play_record_tb b on a.cid=b.cid where start_time < date_add(release_date,interval 7 day)) select cid, count(*) pv, sum(time_len) time_len from t1 group by cid having avg(score)>=3 limit 3
