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
with t2 as( select date from login group by date ) select date,sum(if(first_date = date,1,0)) from t2 left join login using(date) left join( select min(date) first_date,user_id from login group by user_id )t1 using(user_id) group by date order by date