If you need to know which characters have been found / or if found removed from the input string try this:

DECLARE @Temp VARCHAR(30)

DECLARE @Found VARCHAR(30)

SET @Found =''

SET @Temp = 'A<>B=1,! \|-*()%$#@!'

SELECT @Temp AS 'Original input'

BEGIN

WHILE PATINDEX('%[^a-z^0-9]%', @Temp) > 0

BEGIN

SET @Found = @Found + (SELECT SUBSTRING(@Temp,PATINDEX('%[^a-z^0-9]%', @Temp),1))

SET @Temp = STUFF(@Temp, PATINDEX('%[^a-z^0-9]%', @Temp), 1, '')

END

SELECT @Found AS 'Found'

SELECT @Temp AS 'With characters removed'

END

Results:

Found

<>=,! \|-*()%$#@!

With characters removed

AB1

Note that the above will NOT find or remove the '^' character.