題解 | #平均活躍天數(shù)和月活人數(shù)#
平均活躍天數(shù)和月活人數(shù)
http://www.fangfengwang8.cn/practice/9e2fb674b58b4f60ac765b7a37dde1b9
with t1 as ( SELECT uid, DATE_FORMAT(submit_time,'%Y%m%d') month FROM exam_record WHERE score is not NULL and DATE_FORMAT(submit_time,'%Y') = 2021 ), t2 as ( select uid, LEFT(month,6) month from t1 group by uid, month ) select month, round(COUNT(uid)/count(DISTINCT uid),2) avg_active_days,count(DISTINCT uid) mau from t2 group by month
要點(diǎn)：
第一， 20201年
第二，1個(gè)用戶同一天最多只記一次活躍
⑨?們拿它練練面試愣是給他整出幻覺了