题解 | #获得积分最多的人(三)#
获得积分最多的人(三)
http://www.nowcoder.com/practice/d2b7e2a305a7499fb310dc82a43820e8
select user.id, user.name, b.gn from
(select a.*, dense_rank() over (order by a.gn desc) t from
(select user_id, sum(case when type='add' then grade_num else -grade_num end) as gn
from grade_info
group by user_id) a) b
join user on b.user_id=user.id
where b.t=1
