UFN_TAX_VALIDATEDEFAULTTAX

            create function dbo.UFN_TAX_VALIDATEDEFAULTTAX
            (
            )
            returns bit
            with execute as caller
            as 
            begin
                declare @countDefaultTax as int = 0;
                select @countDefaultTax = count(TAX.ID) from dbo.TAX where TAX.DEFAULTFORMERCHANDISE = 1;

                if(@countDefaultTax <= 1)
                begin
                    return 1;
                end
                return 0;

            end