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 round((count(t2.device_id)/count(t1.device_id)),4) as avg_ret from (select distinct device_id ,date from question_practice_detail) as t1 left join (select distinct device_id ,date from question_practice_detail) as t2 on t1.device_id = t2.device_id and t2.date = adddate(t1.date,interval 1 day)

