题解 | 牛客每个人最近的登录日期(三)
牛客每个人最近的登录日期(三)
https://www.nowcoder.com/practice/16d41af206cd4066a06a3a0aa585ad3d
select round(count(*)/(select count(distinct user_id) from login),3) from (SELECT count(a.user_id) from (select user_id,date d1,DATE_ADD(date,INTERVAL 1 DAY) d2 from login) a join login b on a.user_id=b.user_id and a.d2=b.date group by a.user_id) t
