题解 | #获得积分最多的人(一)#
获得积分最多的人(一)
http://www.nowcoder.com/practice/1bfe3870034e4efeb4b4aa6711316c3b
解法：分组求和并排序，然后只显示第一名
SELECT user.name,a.grade_num
FROM (
SELECT g.user_id,SUM(g.grade_num) AS grade_num
FROM grade_info as g
GROUP BY g.user_id
ORDER BY grade_num DESC
LIMIT 1
) AS a JOIN user
ON a.user_id=user.id
