SQL Server存儲過程參數輸出

Question

我有一個存儲過程，爲了這個問題的目的我大大縮小了，但實質上我需要幫助的是這個問題。

如果表xyz中的一行已更新，我需要將ID附加到對方並輸出回調用應用程序。更新按預期工作，問題在於我構建輸出@IPV_ID_Found的方式（請參閱代碼底部的註釋部分）。

@IPV_Status varchar (50), 
@IPV_ID_Found varchar(500) = 'A' OUTPUT 

IF (@IPV_Status ='closed') 
BEGIN 
UPDATE TEST_TBL 
SET 
    Status = 'xyz',   
WHERE     
    ID  = @IPV_ID 

    -- this works for one ID 
    SELECT @IPV_ID_Found = (CAST(@IPV_ID AS VARCHAR(500)))  

    -- this does not work for multiple IDs 
    SELECT @IPV_ID_Found = @IPV_ID_Found + (CAST(@IPV_ID AS VARCHAR(500))) + ',' 

    -- neither does this 
    SET @IPV_ID_Found = @IPV_ID_Found + (CAST(@IPV_ID AS VARCHAR(500))) + ',' 

    SELECT @IPV_ID_Found     
END 

Answer 1

看到的變化：

-- this does not work for multiple IDs 
    SELECT @IPV_ID_Found = @IPV_ID_Found + ',' + (CAST(@IPV_ID AS VARCHAR(500))) 

那麼你將得到的值的連續清單，像1,2,3,4,5

但如果需要返回記錄，那麼你需要不輸出參數，請改用表格變量：

declare @IPV_ID_Found table(Item varchar(500)) 

IF (@IPV_Status ='closed') 
BEGIN 
UPDATE TEST_TBL 
SET 
    Status = 'xyz',   
WHERE     
    ID  = @IPV_ID 

    -- this works for one ID 
    insert @IPV_ID_Found 
    VALUES (CAST(@IPV_ID AS VARCHAR(500)))  

    -- this does not work for multiple IDs 
    INSERT @IPV_ID_Found 
    VALUES (CAST(@IPV_ID AS VARCHAR(500))) 

    SELECT Item FROM @IPV_ID_Found     
END