题解 | #最差是第几名(二)#

select grade
from
(
    select
    grade,
    (select sum(number) from class_grade) total,
    sum(number) over(order by grade) a,
    sum(number) over(order by grade desc) b
    from class_grade
    order by grade
) t
where a >= total/2 and b >= total/2
order by grade