Extract ASCII Characters from a string

This was a common requirement from one of the user in the newsgroups. The user wants to extract all the charaters from a given string and remove number or any other special characters present in the string.

For this requirement I thought of creating a simple function that would remove all the numbers and special characters that are present in the given string and return the output.

------ Copy code from here -------- 
IF EXISTS (SELECT 1 FROM sysobjects WHERE name='ASCIICharOnly')
  DROP FUNCTION dbo.ASCIICharOnly 
GO
 
CREATE FUNCTION dbo.ASCIICharOnly (@CharData VARCHAR(50)) 
RETURNS VARCHAR(50) 
AS 
BEGIN
      DECLARE  @Index INT,
                  @ASCIIData VARCHAR(50),
                  @ASCIIChar INT
      -- Initialization code
      SET @Index = 1
      SET @ASCIIData = ''
 
      WHILE @Index < LEN(@CharData)+1
            BEGIN
            SET @ASCIIChar = ASCII(SUBSTRING(@CharData, @Index, 1))
            --Restrict the result to A-Z and a-z
            IF @ASCIIChar BETWEEN 65 and 90 or @ASCIIChar BETWEEN 97 and 122
            BEGIN
                  -- Construct the output characters 
                  SET @ASCIIData = @ASCIIData + CHAR(@ASCIIChar)
            END
            SET @Index = @Index + 1
            END
      RETURN @ASCIIData
END
GO
-- Sample test
SELECT dbo.ASCIICharOnly ('Vinod1234Kumar!@$%Test') AS CharValue
------ Stop copy of code -----------

Nice little code that does a good activity of removing unwanted charaters from the given string. The typical ouput would be:

CharValue
--------------------------------------------------
VinodKumarTest