with tmp_table as (
    select t1.id, t1.name, sum(t2.grade_num) as grade_sum
    from user as t1 join grade_info as t2
    on t1.id = t2.user_id
    group by t1.id
)
select id, name, grade_sum
from tmp_table
where grade_sum = (select max(grade_sum) from tmp_table)
order by id;