sql - ORDER BY items must appear in the select list if SELECT DISTINCT is specified

Question

I added the columns in the select list to the order by list, but it is still giving me the error:

ORDER BY items must appear in the select list if SELECT DISTINCT is specified.

Here is the stored proc:

CREATE PROCEDURE [dbo].[GetRadioServiceCodesINGroup] 
@RadioServiceGroup nvarchar(1000) = NULL
AS
BEGIN
SET NOCOUNT ON;

SELECT DISTINCT rsc.RadioServiceCodeId,
                rsc.RadioServiceCode + ' - ' + rsc.RadioService as RadioService
FROM sbi_l_radioservicecodes rsc
INNER JOIN sbi_l_radioservicecodegroups rscg 
ON rsc.radioservicecodeid = rscg.radioservicecodeid
WHERE rscg.radioservicegroupid IN 
(select val from dbo.fnParseArray(@RadioServiceGroup,','))
OR @RadioServiceGroup IS NULL  
ORDER BY rsc.RadioServiceCode,rsc.RadioServiceCodeId,rsc.RadioService

END

Answer 1

Try this:

ORDER BY 1, 2

OR

ORDER BY rsc.RadioServiceCodeId, rsc.RadioServiceCode + ' - ' + rsc.RadioService