题解 | #获得积分最多的人(一)#

/*
SELECT u.name, sum(info.grade_num) as grade_sum
from user as u
right JOIN grade_info as info
ON u.id = info.user_id
GROUP BY info.user_id
*/

SELECT t.name, t.grade_sum
FROM (SELECT u.name as name, sum(info.grade_num) as grade_sum
      from user as u
      right JOIN grade_info as info
      ON u.id = info.user_id
      GROUP BY info.user_id) as t
ORDER BY grade_sum DESC
limit 1;