题解 | #牛客每个人最近的登录日期(四)#
牛客每个人最近的登录日期(四)
http://www.nowcoder.com/practice/e524dc7450234395aa21c75303a42b0a
select date,sum( case when (user_id,date) in (select user_id,min(date) from login group by date) then 1 else 0 end ) as new from login group by date order by date;
