UFN_CONSTITUENT_GETPOSTCODE

            create function dbo.UFN_CONSTITUENT_GETPOSTCODE
            (
                @CONSTITUENTID uniqueidentifier
            )
            returns nvarchar(12)
            as
            begin
                declare @POSTCODE nvarchar(12);

                select top 1 
                    @POSTCODE = POSTCODE
                from dbo.ADDRESS
                where ISPRIMARY = 1 and CONSTITUENTID = @CONSTITUENTID;

                if @POSTCODE is null
                    set @POSTCODE = '';

                return @POSTCODE;
            end