题解 | #计算用户的平均次日留存率#
计算用户的平均次日留存率
https://www.nowcoder.com/practice/126083961ae0415fbde061d7ebbde453
with tmp
as(
select
device_id
,date
from question_practice_detail
group by device_id, date
)
select
count(b.device_id) / count(a.device_id)
from tmp a
left join
tmp b
on a.device_id = b.device_id
and a.date = date_sub(b.date, interval 1 day)
