题解 | #获得积分最多的人(一)#

SELECT
    name,
    SUM(grade_num) AS grade_num
FROM
    (
        SELECT
            U.name AS name,
            G.grade_num AS grade_num
        FROM
            grade_info AS G
            LEFT JOIN user AS U ON U.id = G.user_id
    ) AS J
GROUP BY
    name
ORDER BY
    grade_num DESC
LIMIT
    1;