Question

嘿，我是sql / postgreSql的新手。我遇到了问题，我想就如何做到这一点提出建议。下面是我给出的表格。

Student Maths   Physics Chemistry
Joe     80      52       69
Steff   50      90       95
James   62      98       42

我需要查询上表，以便根据标记按降序对学生进行排序。见下文。

Maths   Physcis Chemistry
Joe     James   Steff
James   Steff   Joe
Steff   Joe     James

提前致谢：）

Answer 1

答案的关键是window functions。

with orders as (
    select
        student,
        row_number() over (order by maths desc) as m,
        row_number() over (order by physics desc) as p,
        row_number() over (order by chemistry desc) as c
    from ratings
)
select
    m.student as Maths,
    p.student as Physics,
    c.student as Chemistry
from orders as m
join orders as p on m.m=p.p
join orders as c on m.m=c.c
order by m.m;

对表的每列进行排序

1 个答案: