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)
https://www.nowcoder.com/practice/e524dc7450234395aa21c75303a42b0a
select A.date, sum(if(A.date = B.dt,1,0)) as new from login A left join (select user_id, min(date) as dt from login group by user_id) as B on A.user_id = B.user_id group by A.date