Question

I’ve created the following stored procedure:

ALTER PROCEDURE [dbo].[ExampleSP]
(
    @SearchText NVARCHAR(4000),
    @ID INT = NULL
)
AS
BEGIN
SET NOCOUNT ON;

SELECT 
deID,
deTitle
FROM tblDemo As de
LEFT JOIN tblLinkTable As lnk ON (lnk.ID = de.deID)
WHERE CONTAINS(cstKeywords, @SearchText)
AND ((@ID IS NULL) OR (lnk.ID = @ID))
GROUP BY deID,Title 
ORDER BY de.Title

But I also need to be able to find the first field that is not null out of the following table columns:

deIntroText, deCompanyText, deTimetableText and deExampleText

And i need to do this for each record that is returned from the SELECT.

So I realise that i’d need to create a temporary column to store it in and i guess you’d need to use an IF statement like this:

IF deIntroText IS NOT Null 
THEN TempFieldToReturn = 1

ELSE IF deCompanyText IS NOT Null 
THEN TempFieldToReturn = 2

ELSE IF deTimetableText IS NOT Null 
THEN TempFieldToReturn = 3

ELSE IF deExampleText IS NOT Null
THEN TempFieldToReturn = 4

So my question is – what is the best way to achieve this? Any examples would be appreciated.

Answer 1

No real shortcut – just use a CASE expression:

SELECT
   /* Other Columns */
  CASE
    WHEN deIntroText IS NOT Null THEN 1
    WHEN deCompanyText IS NOT Null THEN 2
    WHEN deTimetableText IS NOT Null THEN 3
    WHEN deExampleText IS NOT Null THEN 4
  ELSE 5 END as OtherColumn
FROM
  /* Rest of query */

This is a Searched CASE – there are actually two variants of CASE. I guessed at 5 if all of the columns are NULL – you might leave off the ELSE 5 portion, if you want a NULL result in such a case.