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
次日留存率关键就是对时间差=1条件计数
select round(sum(timestampdiff(day,注册日期,date)=1)/count(distinct t.user_id),3) from login as t right join (select user_id as g,min(date) as 注册日期 from login group by user_id )as t2 on t.user_id=g;
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