题解 | #获得积分最多的人(一)#

有大佬知道，这里用count()函数为什么不可以呢？报错说里面不存在count()
select u.name,a.grade_sum
from user as u
left join (select g.user_id,sum(g.grade_num)as grade_sum
from grade_info as g
group by g.user_id
having count(user_id)>=2)as a
on u.id = a.user_id;