CREATE FUNCTION CalculateRatio(@numerator int, @denominator int)
RETURNS nvarchar(max)
AS
BEGIN

	declare @ratio nvarchar(max)
	declare @greatestcommondivisor int
	declare @x int
	declare @y int
	set @x = @numerator
	set @y = @denominator
	declare @tmp int

	if (@denominator > 0)
	begin
		while (@x > 0)
		begin
			if @x < @y begin
				set @tmp = @x
				set @x = @y
				set @y = @tmp
			end
			set @x = @x % @y
		end
	end

	set @greatestcommondivisor = @y

	if (@numerator = 0 or @denominator = 0 or @greatestcommondivisor = 1)
	begin
		set @ratio = convert(nvarchar(max), @numerator) + ':' + convert(nvarchar(max), @denominator)
	end
	else
	begin
		set @ratio = convert(nvarchar(max), @numerator/@greatestcommondivisor) + ':' + convert(nvarchar(max), @denominator/@greatestcommondivisor)
	end

	return @ratio

END