题解 | #平均活跃天数和月活人数#
平均活跃天数和月活人数
https://www.nowcoder.com/practice/9e2fb674b58b4f60ac765b7a37dde1b9
SELECT
date_format(submit_time,'%Y%m') month,
round(count(DISTINCT concat(uid,date_format(submit_time,'%Y-%m-%d')))/count(DISTINCT uid),2) avg_active_days,
count(DISTINCT uid) mau
FROM exam_record
WHERE submit_time IS NOT NULL AND year(submit_time) = '2021'
GROUP BY date_format(submit_time,'%Y%m');