How do I remove extended ASCII characters from a string in T-SQL?

Question

I need to filter out (remove) extended ASCII characters from a SELECT statement in T-SQL.

I\'m using a stored procedure to do so.

Expected input:

<         


        

Answer 1

Just correcting above code (it was cutting DOTs)

CREATE FUNCTION [dbo].[RemoveNonASCII] 
(
    @nstring nvarchar(255)
)
RETURNS nvarchar(255)
AS
BEGIN

    DECLARE @Result nvarchar(255)
    SET @Result = ''

    DECLARE @nchar nvarchar(1)
    DECLARE @position int

    SET @position = 1
    WHILE @position <= LEN(@nstring)
    BEGIN
        SET @nchar = SUBSTRING(@nstring, @position, 1)
        --Unicode & ASCII are the same from 1 to 255.
        --Only Unicode goes beyond 255
        --0 to 31 are non-printable characters
        IF (UNICODE(@nchar) between 192 and 198) or (UNICODE(@nchar) between 225 and 230) -- letter A or a with accents
            SET @nchar = 'a'
        IF (UNICODE(@nchar) between 200 and 203) or (UNICODE(@nchar) between 232 and 235) -- letter E or e with accents
            SET @nchar = 'e'
        IF (UNICODE(@nchar) between 204 and 207) or (UNICODE(@nchar) between 236 and 239) -- letter I or i with accents
            SET @nchar = 'i'
        IF (UNICODE(@nchar) between 210 and 214) or (UNICODE(@nchar) between 242 and 246) or (UNICODE(@nchar)=240) -- letter O or o with accents
            SET @nchar = 'o'
        IF (UNICODE(@nchar) between 217 and 220) or (UNICODE(@nchar) between 249 and 252)  -- letter U or u with accents
            SET @nchar = 'u'
        IF (UNICODE(@nchar)=199)  or (UNICODE(@nchar)=231)  -- letter Ç or ç 
            SET @nchar = 'c'
        IF (UNICODE(@nchar)=209)  or (UNICODE(@nchar)=241)  -- letter Ñ or ñ 
            SET @nchar = 'n'
        IF (UNICODE(@nchar) between 45 and 46) or (UNICODE(@nchar) between 48 and 57) or (UNICODE(@nchar)  between 64 and 90) or (UNICODE(@nchar) = 95) or (UNICODE(@nchar)  between 97 and 122)
            SET @Result = @Result + @nchar
        SET @position = @position + 1
    END
    set @Result = lower(@Result) -- e-mails in lower case
    RETURN @Result

END