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 1,2 ) 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)