CREATE function [dbo].[GetGGpresenze] (@data1 date,@Date2 date)
Returns Int
WITH EXECUTE AS CALLER
AS
BEGIN
DECLARE @Giorni Int
SET @giorni =Case DATEDIFF(day,@data1,@Date2) when '0' then '1' else DATEDIFF(day,@Data1,@Date2)End  
SET @giorni=Isnull(@giorni,0)
RETURN(@giorni)
END