题目描述：sql语句查询每个用户最近一天登录的日子，用户的名字，以及用户用的设备的名字，并且查询结果按照user的name升序排序。
考点：group by 子句常见错误：
select 子句中只能存在以下三种元素：常数、聚合函数、group by子句指定列(聚合键)
所以下面这么写法错误：

select u.name as u_n, c.name as c_n, max(l.date) as d  #列名c.name as c_n不能包含
from login as l
inner join user as u
on l.user_id=u.id
inner join client as c
on l.client_id=c.id
group by u.name
order by u.name asc

我的代码（多列名IN）：

select u.name as u_n,
       c.name asc_n,
       l.date
from login l join user u on l.user_id=u.id
             join client c on l.client_id=c.id
where (l.user_id,l.date) in (select user_id,max(date) from login group by user_id)
order by u_n