存储过程 - 表列名称作为变量

时间:2013-08-22 15:00:33

标签: sql stored-procedures db2

我这里有一个从示例数据库调用表列的存储过程,但我的问题是我想将一个列名称变成一个变量,以便我可以在条件中使用它。我的代码不起作用,但我不知道如何将其作为变量。

我想将列名SALARY作为变量。

这是我的代码:

CREATE PROCEDURE TAXEXEMPT ()

    DYNAMIC RESULT SETS 1
    LANGUAGE SQL

BEGIN

    DECLARE display CURSOR WITH RETURN TO CLIENT FOR

        SELECT EMPNO, LASTNAME, SALARY, SALARY AS "TAX EXEMPTION" 
        FROM EMPLOYEE 
        WHERE WORKDEPT BETWEEN 'C01' AND 'D21';

        IF ( SALARY < 15001 ) THEN
            --DO NOTHING
        ELSEIF ( SALARY >= 15001 OR SALARY <= 22000 ) THEN
            UPDATE EMPLOYEE SET "TAX EXEMPTION" = SALARY * 1.03;
        ELSEIF ( SALARY >= 22001 OR SALARY <= 32000 ) THEN
            UPDATE EMPLOYEE SET "TAX EXEMPTION" = (SALARY * 1.05) + 100;
        ELSEIF ( SALARY >= 32001 OR SALARY <= 45000 ) THEN
            UPDATE EMPLOYEE SET "TAX EXEMPTION" = (SALARY * 1.07) + 200;
        ELSE
            --DO NOTHING
        END IF; 

    OPEN display;

END

提前感谢任何形式的帮助。

1 个答案:

答案 0 :(得分:3)

你想要的是一个CASE表达式:

DECLARE display CURSOR WITH RETURN TO CLIENT FOR

         SELECT EMPNO, LASTNAME, SALARY, 
                   CASE 
                     WHEN SALARY < 15001 THEN SALARY 
                     WHEN SALARY BETWEEN 15001 AND <= 22000 THEN SALARY * 1.03
                     WHEN SALARY BETWEEN 20001 AND <= 32000 THEN (SALARY * 1.05) + 100
                     ...
                     ELSE SALARY
                   END AS "TAX EXEMPTION" 
         FROM EMPLOYEE 
         WHERE WORKDEPT BETWEEN 'C01' AND 'D21';

     OPEN display;