TSQL Roman Numeral Converter

roman_numeral.sql

declare @numeral varchar(10)
set @numeral = 'MCMXIV'

declare @lookup table(c char(1),v smallint)
insert into @lookup 
select 'M',1000 union all
select 'D',500 union all
select 'C',100 union all
select 'L',50 union all
select 'X',10 union all
select 'V',5 union all
select 'I',1 

set @numeral = upper(@numeral)
;with numeral(num,i)
as
(
	select reverse(@numeral), cast(0 as int)
	union all
	select 
		reverse(left(reverse(num),len(num) - 1)),
		i + 
		case 
		when i < 3 and v < 3 then v 
		when i <= v then v
		when i > v then v * -1
		else 0
		end
	from numeral
	inner join @lookup
	on left(num,1) = c
	where len(num) >= 1
)
select i from numeral where len(num) = 0