Question

我有一个包含这些值的表格，我希望显示带有替代值的结果，并且我还想更改客户1，客户3，客户2等值的顺序，但它们必须按其他顺序排列。 customername。

    CREATE TABLE TEST (
      customername varchar(50)
    );

    INSERT INTO TEST VALUES('CUSTOMER 1');
    INSERT INTO TEST VALUES('CUSTOMER 1');
    INSERT INTO TEST VALUES('CUSTOMER 1');
    INSERT INTO TEST VALUES('CUSTOMER 2');
    INSERT INTO TEST VALUES('CUSTOMER 2');
    INSERT INTO TEST VALUES('CUSTOMER 2');
    INSERT INTO TEST VALUES('CUSTOMER 3');
    INSERT INTO TEST VALUES('CUSTOMER 3');
    INSERT INTO TEST VALUES('CUSTOMER 3');

期望的结果：

    CUSTOMER 2
    CUSTOMER 1
    CUSTOMER 3
    CUSTOMER 2
    CUSTOMER 1
    CUSTOMER 3
    CUSTOMER 2
    CUSTOMER 1
    CUSTOMER 3

我试过了：

    SELECT  customername
    FROM    TEST
    ORDER BY ROW_NUMBER() OVER ( PARTITION BY customername ORDER BY  customername)

返回

    CUSTOMER 2
    CUSTOMER 1
    CUSTOMER 3
    CUSTOMER 2
    CUSTOMER 1
    CUSTOMER 3
    CUSTOMER 1
    CUSTOMER 3
    CUSTOMER 2

N.B 值可以是3,2,1之类的整数，因为上面只是一个例子

Answer 1

您需要一个额外的表来定义所需的顺序：

create table dict(customername varchar(50), priority int);
insert into dict values
('CUSTOMER 2', 1),
('CUSTOMER 1', 2),
('CUSTOMER 3', 3);

select customername
from test
join dict
using (customername)
order by
    row_number() over (partition by customername),
    priority;

 customername 
--------------
 CUSTOMER 2
 CUSTOMER 1
 CUSTOMER 3
 CUSTOMER 2
 CUSTOMER 1
 CUSTOMER 3
 CUSTOMER 2
 CUSTOMER 1
 CUSTOMER 3
(9 rows)

使用预定义的值顺序选择列值

1 个答案: