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
1、求所有新用户以及登录日期
2、按日期统计新用户数
3、并上没有新用户登录的日期
1、求所有新用户以及登录日期：
select distinct min(date)as date ,user_id from login group by user_id2、按日期统计新用户数
select date,count(user_id)as new from ( select distinct min(date)as date ,user_id from login group by user_id)a group by date3、并上没有新用户登录的日期
union select date,0 as new from login where date not in (select distinct min(date)as date from login group by user_id) order by date
4、总代吗：
select date,count(user_id)as new from ( select distinct min(date)as date ,user_id from login group by user_id)a group by date union select date,0 as new from login where date not in (select distinct min(date)as date from login group by user_id) order by date
