题解 | #牛客每个人最近的登录日期(二)#
牛客每个人最近的登录日期(二)
https://www.nowcoder.com/practice/7cc3c814329546e89e71bb45c805c9ad
#用窗口函数解
#多表链接更方便测试,在工作中比较常用
select u_n
,c_n,date
from
(
select tb_2.name as u_n
,tb_3.name as c_n
,tb_1.date
,row_number() over (partition by tb_2.name order by date desc) as max_date
from
(
(
select id
,user_id
,client_id
,date
from login
) tb_1
left join
(
select id
,name
from user
) tb_2
on tb_1.user_id = tb_2.id
left join
(
select id
,name
from client
) tb_3
on tb_1.client_id = tb_3.id
)
) t
where max_date = 1


