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(t.tt/count(distinct a.user_id),3) from login a
join(select count(distinct a.user_id) tt from login a
join login b
on a.user_id = b.user_id
and b.date = date_add(a.date,interval 1 day)) t;


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