题解 | #查找入职员工时间排名倒数第三的员工所有信息#

select distinct u.name, sum(g.grade_num) as grade_sum #名字去重，分数求总
FROM user as u
right join grade_info as g
on u.id = g.user_id
group by g.user_id
order by grade_sum desc
limit 1
;