题解 | #牛客每个人最近的登录日期(三)#
牛客每个人最近的登录日期(三)
https://www.nowcoder.com/practice/16d41af206cd4066a06a3a0aa585ad3d
with a as(
select
user_id
,min(date) as date
from login
group by user_id
)
select
round(count(distinct case when datediff(l.date,a.date)=1 then a.user_id else NULL end)/count(distinct l.user_id),3) as p
from login l left join a on l.user_id =a.user_id
不经常做老是会忘。。再做几遍
1、忘记命名min(date)
2、忘了明确user_id字段是哪个表里的了
