如何使用 Postgres 做到这一点？

Question

我有一个 table 这样的结构

id  status action amount fid
1    P      Yes   3000    10
2    P      No    2000    10
3    P      Yes   6000    10
4    D      Yes   500     10
5    D      No    600     10
6    V      Yes   800     10

我想用 --> status P action Yes，status D action No，status V action Yes 过滤一次。结果将基于 fid.

这样输出---->

amount(name1) amount(name2) amount(name3)
9000            600          800

Answer 1

假设您只打算报告上面示例数据中显示的三种状态，我们可以尝试：

SELECT
    fid,
    SUM(amount) FILTER (WHERE status = 'P' AND action = 'Yes') AS amount_1,
    SUM(amount) FILTER (WHERE status = 'D' AND action = 'No')  AS amount_2,
    SUM(amount) FILTER (WHERE status = 'V' AND action = 'Yes') AS amount_3
FROM yourTable
GROUP BY fid;

如何使用 Postgres 做到这一点？

How to do this with Postgres?

postgresql

postgresql-9.3

Demo