题解 | #牛客每个人最近的登录日期(二)#

采用子查询查询出牛客最近登录的个人id和时间，再去做设备匹配：
select b.name,c.name,a.date from login a
join user b on a.user_id = b.id
join client c on a.client_id = c.id
where (a.user_id,a.date) in (select user_id,max(date) from login group by user_id)
order by b.name asc