Question

我试图基于IF条件在UDF中返回两个不同的SQL语句。到目前为止我还没能正确完成，下面的代码不起作用。我怎么能这样做？

CREATE FUNCTION BELSIZE.TEST (aSTRING VARCHAR(50))
    RETURNS TABLE(
    column1 INTEGER
    , column2 INTEGER   
    , column3 VARCHAR(50)
 )
 ------------------------------------------------------------------------
F1: BEGIN ATOMIC

DECLARE v_string VARCHAR(50);
SET v_string = aSTRING;

IF v_string = '123' THEN 

        With v (column1, column2, column3) as (
            VALUES (1, 10231011, 'PRINCIPAL')
            , (1, 10231012, 'ADDITIONAL')
            , (-1, 10231031, 'REDEEM')
        ) select * from v;

END IF;

RETURN
        With v (column1, column2, column3) as (
            VALUES (1, 10231011, 'PRINCIPAL 456')
            , (1, 10231012, 'ADDITIONAL 456')
            , (-1, 10231031, 'REDEEM 456')
        ) select * from v;


END

感谢。

Answer 1

由于您需要基于输入字符串的2个不同结果，因此您的return语句应该位于IF-ELSE逻辑上。您处理它的方式在查询中是错误的。它总是试图在返回块中返回一个。

我已更正符合您要求的查询。使用IF-ELSE逻辑。它是用SQL-SERVER

写的

CREATE FUNCTION dbo.testFn(@aSTRING  VARCHAR(50))  
RETURNS @rtnTable TABLE(
    column1 INTEGER
    , column2 INTEGER   
    , column3 VARCHAR(50)
 )   
AS   
BEGIN  

    IF @aSTRING = '123'
    BEGIN
        INSERT INTO @rtnTable
        VALUES (1, 10231011, 'PRINCIPAL')
            , (1, 10231012, 'ADDITIONAL')
            , (-1, 10231031, 'REDEEM')
    END
    ELSE
    BEGIN 
        INSERT INTO @rtnTable
        VALUES (1, 10231011, 'PRINCIPAL 456')
            , (1, 10231012, 'ADDITIONAL 456')
            , (-1, 10231031, 'REDEEM 456')
    END 

    RETURN
END

Answer 2

您应该指定您的平台和Db2版本......

但是，我不相信这会有所作为。

Db2从用户定义表函数（UDTF）或存储过程返回行的方式是以函数/过程内部定义的游标结束。

所以你需要这样的东西......

CREATE FUNCTION BELSIZE.TEST (aSTRING VARCHAR(50))
    RETURNS TABLE(
    column1 INTEGER
    , column2 INTEGER   
    , column3 VARCHAR(50)
 )

begin atomic
declare C1 cursor with return to client for
        With v (column1, column2, column3) as (
            VALUES (1, 10231011, 'PRINCIPAL')
            , (1, 10231012, 'ADDITIONAL')
            , (-1, 10231031, 'REDEEM')
        ) select * from v;

declare C2 cursor with return to client for 
        With v (column1, column2, column3) as (
            VALUES (1, 10231011, 'PRINCIPAL 456')
            , (1, 10231012, 'ADDITIONAL 456')
            , (-1, 10231031, 'REDEEM 456')
        ) select * from v;

IF v_string = '123' THEN 
  open C1;
else
  open C2;
END IF;

RETURN
END

Answer 3

我会将你的UDF编码为这样的

CREATE FUNCTION BELSIZE.TEST (aSTRING VARCHAR(50))
    RETURNS TABLE(
      column1 INTEGER
    , column2 INTEGER   
    , column3 VARCHAR(50)
 )
RETURN
    SELECT column1, column2, column3 FROM TABLE(
        VALUES (0, 1, 10231011, 'PRINCIPAL')
        ,      (0, 1, 10231012, 'ADDITIONAL')
        ,      (0,-1, 10231031, 'REDEEM')
        ,      (1, 1, 10231011, 'PRINCIPAL 456')
        ,      (1, 1, 10231012, 'ADDITIONAL 456')
        ,      (1,-1, 10231031, 'REDEEM 456')
        ) AS v(i, column1, column2, column3)
    WHERE i = CASE WHEN aSTRING = '123' THEN 0 ELSE 1 END

UDF返回不同的SQL语句

3 个答案: