UFN_RESERVATION_HASEMPTYITINERARY

            create function dbo.UFN_RESERVATION_HASEMPTYITINERARY (
                @RESERVATIONID uniqueidentifier
            )
            returns bit
            with execute as caller
            as begin
                if exists (
                    select 1
                    from dbo.[ITINERARY]
                    where
                        [RESERVATIONID] = @RESERVATIONID and
                        --Itinerary has nothing

                        (
                            not exists (select 1 from dbo.[ITINERARYITEM] where [ITINERARYID] = [ITINERARY].[ID]) and
                            not exists (select 1 from dbo.[ITINERARYRESOURCE] where [ITINERARYID] = [ITINERARY].[ID]) and
                            not exists (select 1 from dbo.[ITINERARYSTAFFRESOURCE] where [ITINERARYID] = [ITINERARY].[ID])
                        )
                )
                    return 1;

                return 0;
            end