UFN_ZIPCITYSTATE_GETPOSTCODE

                create function dbo.UFN_ZIPCITYSTATE_GETPOSTCODE
                (
                    @ID uniqueidentifier
                )
                returns nvarchar(12)
                with execute as caller
                as
                begin
                    declare @POSTCODE nvarchar(12);

                    select 
                        @POSTCODE = POSTCODE
                    from
                        dbo.ZIPCITYSTATE
                    where
                        ID = @ID;

                    return coalesce(@POSTCODE, '');
                end