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)
http://www.nowcoder.com/practice/16d41af206cd4066a06a3a0aa585ad3d
select round(count(distinct t1.user_id)/(select count(distinct user_id) from login) ,3) from login t1 join login t2
on t1.user_id=t2.user_id and t2.date=date_add(t1.date,interval 1 day)

