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
t1 as(
select
user_id,
date,
dense_rank()over(partition by user_id order by date) as uf
from
login
),
t2 as(
select
date,
sum(
case
when uf=1 then 1
else 0
end
) as new
from
t1
group by
date
)
select * from t2 order by date
