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 distinct(concat(year(start_time),'0',month(start_time))) as month, round(count(distinct uid ,day(submit_time))/count(distinct uid),2) as avg_active_days, count(distinct uid ) as mau from exam_record where year(start_time)=2021 and submit_time is not null group by month
