题解 | #Datediff 函数 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 b.user_id)/count(distinct a.user_id),3) as p
from (select user_id,min(date) as date from login group by 1) as a
left join
login as b
on a.user_id =b.user_id
and datediff(b.date,a.date)=1
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