Question

What’s the proper syntax here?

If (@timestamp < (Select PromoStartTimestamp From @promo))
    RAISERROR('Code not valid until ' + (Select PromoStartTimestamp From @promo)
              ,16
              ,1);

I’ve tried:

If (@timestamp < (Select PromoStartTimestamp From @promo))
    RAISERROR(N'Code not valid until @starttimestamp'
              ,16
              ,1
              ,(Select PromoStartTimestamp From @promo));

Answer 1

You can use %s as a string substitution parameter in RAISERROR:

DECLARE @PromoStartTimestamp DATETIME
DECLARE @PromoStartTimestampString VARCHAR(50)

SELECT @PromoStartTimestamp = PromoStartTimestamp From @promo
SELECT @PromoStartTimestampString = CAST(@PromoStartTimestamp AS VARCHAR)

If (@timestamp < @PromoStartTimestamp)
    RAISERROR(N'Code not valid until %s'
              ,16
              ,1
              ,@PromoStartTimestampString);