with shebei as (
select user_id,name,date
    from login a 
    left join client b
    on a.client_id=b.id
    where date in(
    select max(date)
    from login
    group by user_id
)
),
t2 as (
    select b.name as u_n,a.name as c_n,max(date) as date
from shebei a 
left join user b 
on a.user_id=b.id
group by b.name,a.name
order by b.name
    )
select u_n,c_n,max(date) as date
from t2
group by u_n
order by u_n

标题

先找出所有用户对应的登陆日期，登录设备编号和登录设备名称
然后再从以上信息中找到不同设备最近一次登录的日期、设备
最后再从最近一次登录的信息中找出在所有设备情况下最近一次登录的信息