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