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
with a as(
select distinct uid,date_format(start_time,'%Y%m') as ym,date_format(start_time,'%Y%m%d') as ymd
from exam_record
where year(start_time)=2021 and score is not null
)
select ym,round(count(ymd)/count(distinct uid),2) as avg_active_days,count(distinct uid) as mau
from a
group by 1