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
b.date,
(case when c.new is not null then c.new else 0 end) new
from
(select date from
login
group by
date
) b
left join
(
select
minDate , count(user_id) new
from
(
select
user_id,
min(date) minDate
from
login
group by
user_id
) a
group by a.minDate
) c
on b.date = c.minDate