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(date_2)/count(date_1))as avg_ret from( select distinct q.device_id,q.date as date_1 from question_practice_detail as q ) as q1 left join ( select distinct q.device_id,date_add(q.date,interval 1 day) as date_2 from question_practice_detail as q ) as q2 on q1.device_id = q2.device_id and date_1 = date_2