Increasing Alphanumeric value in user defined function - sql

Question

I'm trying to code a user defined function under SQL Server 2005 that will increase integer part of alphanumeric value by one. For example, uf_AlphanumericIncrease ('A000299') should return 'A000300'. Here's what I've done so far;
ALTER FUNCTION uf_AlphaNumericIncrement
(
#ID varchar(10)
)
RETURNS VARCHAR(10) AS
BEGIN
DECLARE #RES varchar(10);
IF SUBSTRING(#ID,LEN(#ID),1)='9'
SET #RES=SUBSTRING(#ID,1,LEN(#ID)-2)+CAST (CAST(SUBSTRING(#ID,LEN(#ID)-1,1) AS smallint)+1 AS VARCHAR(10))+'0';
ELSE
SET #RES=SUBSTRING(#ID,1,LEN(#ID)-1)+CAST (CAST(SUBSTRING(#ID,LEN(#ID),1) AS smallint)+1 AS VARCHAR(10));
RETURN #RES;
END
But as you can see it only works for last digit. I need to get it under loop so it can work for A002999 and so on. Any ideas?
Edit: Given value might have alpha prefix longer than one character, or none at all.

Answer 1

Now works with any length of prefix and number part (well upto 20 each)
DECLARE #prefix varchar(20), #numberstr varchar(20), #number int, #Val varchar(40)
SELECT #Val = 'ABCD000006'
--SELECT #Val = 'A03'
SELECT #prefix = LEFT(#Val, PATINDEX ('%[0-9]%', #Val) -1)
SELECT #numberstr = SUBSTRING(#Val, PATINDEX ('%[0-9]%', #Val), 8000)
SELECT #number = CAST(#numberstr AS int) + 1
SELECT #prefix + RIGHT(REPLACE(SPACE(LEN(#numberstr)), ' ', '0') + CAST(#number AS varchar(20)), LEN(#numberstr))

Answer 2

CREATE FUNCTION dbo.uf_ANinc
(
#in varchar(10)
)
RETURNS varchar(10) AS
BEGIN
DECLARE #prefix varchar(10);
DECLARE #res varchar(10);
DECLARE #pad varchar(10);
DECLARE #num int;
DECLARE #start int;
SET #start = PATINDEX('%[0-9]%',#in);
SET #prefix = LEFT(#in, #start - 1 );
SET #num = CAST( RIGHT( #in, LEN(#in) - #start ) AS int ) + 1
SET #pad = REPLICATE( '0', 10 - LEN(#prefix) - CEILING(LOG(#num)/LOG(10)) );
SET #res = #prefix + #pad + CAST( #num AS varchar);
RETURN #res
END
GO
SELECT dbo.uf_ANinc('ABC000123');

Answer 3

Assuming that the alpha part of your alphanumeric is always only the first character, this should work.
EDIT: OK, if the alpha part varies in length this gets ugly pretty quickly for a UDF. This is just a quick-and-dirty solution, so it can probably be optimized a bit, but the logic should be sound.
EDIT AGAIN: patindex() ftw - I learned something new today ;-)
ALTER FUNCTION uf_AlphaNumericIncrement
(
#ID varchar(10)
)
RETURNS VARCHAR(10) AS
BEGIN
DECLARE #RES varchar(10);
DECLARE #num int;
DECLARE #prefix varchar(10);
set #prefix = left(#id, patindex('%[0-9]%', #id) -1)
set #num = cast(right(#id, len(#id) - len(#prefix)) as int) + 1
set #res = #prefix + replicate('0', len(#id) - len(#prefix) - len(#num)) + cast(#num as varchar(10))
RETURN #RES;
END