You'll get null if there're no records matching query conditions.

>I ´ve designed this function in sql server but it returns null instead of the correct value, i execute the sql query and i see the correct value.
>
>Any Idea what is wrong.
>
>

>ALTER FUNCTION dbo.TotVenci
>	(@IdCliente Int,
>	@hasta datetime	)
>RETURNS money
>AS
>	BEGIN
>	Declare @totvenci money
>	set @totvenci=(select sum(venci.importe) from venci where
>		venci.IdCliente=@IdCliente and venci.fecha<=@hasta )
>		RETURN @totvenci
>	END