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
select
count(t2.date)/count(t1.date) as avg_ret
from (
select
distinct device_id,date
from question_practice_detail )as t1
left join
(
select
distinct device_id,date_add(date,interval 1 day) as date
from question_practice_detail
) as t2
on t1.device_id=t2.device_id and t1.date=t2.date