To remove or replace multiple special character from string using sql queries.

CREATE FUNCTION [FN_REMOVE_SPECIAL_CHARACTER] (  
 @INPUT_STRING varchar(300))
RETURNS VARCHAR(300)
AS 
BEGIN
 
--declare @testString varchar(100),
DECLARE @NEWSTRING VARCHAR(100) 
-- set @teststring = '@san?poojari(darsh)'
 SET @NEWSTRING = @INPUT_STRING ; 
With SPECIAL_CHARACTER as
(
SELECT '>' as item
UNION ALL 
SELECT '<' as item
UNION ALL 
SELECT '(' as item
UNION ALL 
SELECT ')' as item
UNION ALL 
SELECT '!' as item
UNION ALL 
SELECT '?' as item
UNION ALL 
SELECT '@' as item
UNION ALL 
SELECT '*' as item
UNION ALL 
SELECT '%' as item
UNION ALL 
SELECT '$' as item
 )
SELECT @NEWSTRING = Replace(@NEWSTRING, ITEM, '') FROM SPECIAL_CHARACTER  
return @NEWSTRING 
END 

select dbo.[FN_REMOVE_SPECIAL_CHARACTER] ('@s()antosh')

CREATE FUNCTION [dbo].[udfGetCharacters](@inputString VARCHAR(MAX), @validChars VARCHAR(100))
RETURNS VARCHAR(500) AS
BEGIN
 
 WHILE @inputString like '%[^' + @validChars + ']%'
  SELECT @inputString = REPLACE(@inputString,SUBSTRING(@inputString,PATINDEX('%[^' + @validChars + ']%',@inputString),1),'')

 RETURN @inputString
END

--Usage of the function
select [dbo].udfGetCharacters('utkarsh puranik`s blog' ,'0-9a-z ')

--output
utkarsh puraniks blog