题解 | #牛客每个人最近的登录日期(五)#
牛客每个人最近的登录日期(五)
https://www.nowcoder.com/practice/ea0c56cd700344b590182aad03cc61b8
with t as(
select distinct user_id,date
from login )
select d.date
,round(ifnull(count(t2.user_id)/count(t1.user_id),0),3)
from (select distinct date from login) d
left join (
select user_id,min(date) fd
from t
group by user_id
)t1
on d.date=t1.fd
left join t t2
on t1.user_id =t2.user_id and date_add(t1.fd,INTERVAL 1 DAY)=t2.date
group by d.date