Question

I’m wanting to throw an error when reference keys are missing, however instead of failing through a integrity check, I want to list out the missing keys. I’ve created the below which works. However I’m hoping there is a way to optimise it and reduce the number of lines of code.

DECLARE @NonRefKeys INT

SELECT @NonRefKeys = SUM(1)
FROM staging.Sale sa
WHERE NOT EXISTS (
    SELECT cu.Customer_Shipping_ID
    FROM staging.Customer cu
    WHERE LTRIM(RTRIM(sa.Customer_Shipping_ID)) = LTRIM(RTRIM(cu.Customer_Shipping_ID)))

IF @NonRefKeys IS NOT NULL
BEGIN

IF OBJECT_ID('tempdb..#Missing_Ref') IS NOT NULL
DROP TABLE #Missing_Ref;

SELECT sa.Customer_Shipping_ID AS ID
INTO #Missing_Ref
FROM staging.Sale sa
WHERE NOT EXISTS (
        SELECT cu.Customer_Shipping_ID
        FROM staging.Customer cu
        WHERE LTRIM(RTRIM(sa.Customer_Shipping_ID)) = LTRIM(RTRIM(cu.Customer_Shipping_ID)))

DECLARE @Current_ID VARCHAR(50);
DECLARE @Missing_ID VARCHAR(MAX) = '';
DECLARE @Output_Error VARCHAR(MAX);

DECLARE id_cursor CURSOR FOR
SELECT ID
FROM #Missing_Ref;

OPEN id_cursor
FETCH NEXT FROM id_cursor INTO @Current_ID

WHILE @@FETCH_STATUS = 0
BEGIN
    IF (@Missing_ID != '')
        SET @Missing_ID = @Missing_ID + ', ';

    SET @Missing_ID = @Missing_ID + @Current_ID;

    FETCH NEXT FROM id_cursor INTO @Current_ID
END
CLOSE id_cursor
DEALLOCATE id_cursor

SET @Output_Error = 'ERROR: Key/s ' + @Missing_ID + ' for Customer Shipping ID missing from Customer table';

RAISERROR (@Output_Error,16,1)
END

Answer 1

Check this out… you can update a variable without having to create a temp table

There is a trailing “,” that you have to remove.

Declare @MissingIDList VarChar (Max) = ''

DROP Table #MyTableOfMissingIds

Select *
Into #MyTableOfMissingIds
From 
(   Select 1 MissingId
    Union Select 2
    Union Select 3
    Union Select 4
    Union Select 5
    Union Select 6
) xx

Update #MyTableOfMissingIds
Set @MissingIDList = @MissingIDList + Cast (MissingId as VarChar) + ','

Declare @Output_Error VarChar (Max)
SET @Output_Error = 'ERROR: Key/s ' + @MissingIDList + ' for Customer Shipping ID missing from Customer table';

RAISERROR (@Output_Error,16,1)

The Update statement in my example can be replaced with one of your tables like this (OTTOMH, so syntax may need to be verified)

Declare @MissingIDList VarChar (Max) = ''
Declare @Output_Error VarChar (Max)

UPDATE staging.Sale SET 
Set @MissingIDList = @MissingIDList + Cast (Customer_Shipping_ID as VarChar) + ','
WHERE NOT EXISTS (
        SELECT cu.Customer_Shipping_ID
        FROM staging.Customer cu
        WHERE LTRIM(RTRIM(sa.Customer_Shipping_ID)) = LTRIM(RTRIM(cu.Customer_Shipping_ID)))

SET @Output_Error = 'ERROR: Key/s ' + @MissingIDList + ' for Customer Shipping ID missing from Customer table';

RAISERROR (@Output_Error,16,1)

Now, if you’re good with using XML, here is another cool method:

Declare @MissingIDList VarChar (Max) = ''
Declare @Output_Error VarChar (Max)

DROP Table #MyTableOfMissingIds

Select *
Into #MyTableOfMissingIds
From 
(   Select 1 MissingId
    Union Select 2
    Union Select 3
    Union Select 4
    Union Select 5
    Union Select 6
) xx

SELECT @MissingIDList = 
    SUBSTRING(
                (   SELECT ',' + Cast (MissingId as VarChar)
                    FROM #MyTableOfMissingIds s
                    ORDER BY 1
                    FOR XML PATH('')
                )
                ,2,200000
            )

SET @Output_Error = 'ERROR: Key/s ' + @MissingIDList + ' for Customer Shipping ID missing from Customer table';

RAISERROR (@Output_Error,16,1)