题解 | 最差是第几名(一)

#解法1
select
    grade,
    sum(number) over (
        order by
            grade
    )
from
    class_grade
order by
    grade



#解法2
select
    grade,
    (
        case
            grade
            when 'A' then (
                select
                    sum(number)
                from
                    class_grade
                where
                    grade <= 'A'
            )
            when 'B' then (
                select
                    sum(number)
                from
                    class_grade
                where
                    grade <= 'B'
            )
            when 'C' then (
                select
                    sum(number)
                from
                    class_grade
                where
                    grade <= 'C'
            )
            when 'D' then (
                select
                    sum(number)
                from
                    class_grade
                where
                    grade <= 'D'
            )
            else (
                select
                    sum(number)
                from
                    class_grade
            )
            end
        )
        FROM
            class_grade
        order by
            grade asc