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((select count(distinct l1.user_id)
from login l1
inner join login l2
on datediff(l2.date,l1.date)=1 and l1.user_id=l2.user_id
inner join(
select min(date) min_date,user_id
from login
group by user_id
) t
on l1.date=t.min_date and l1.user_id=t.user_id)/count(distinct user_id),3) p
from login;
