MySQL Function to remove accents and special characters

fn_remove_accents.sql

DROP FUNCTION IF EXISTS fn_remove_accents;
DELIMITER |
CREATE FUNCTION fn_remove_accents( textvalue VARCHAR(10000) ) RETURNS VARCHAR(10000)

BEGIN

    SET @textvalue = textvalue COLLATE utf8_general_ci;;

    -- ACCENTS
    SET @withaccents = 'ŠšŽžÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÑÒÓÔÕÖØÙÚÛÜÝŸÞàáâãäåæçèéêëìíîïñòóôõöøùúûüýÿþƒ';
    SET @withoutaccents = 'SsZzAAAAAAACEEEEIIIINOOOOOOUUUUYYBaaaaaaaceeeeiiiinoooooouuuuyybf';
    SET @count = LENGTH(@withaccents);

    WHILE @count > 0 DO
        SET @textvalue = REPLACE(@textvalue, SUBSTRING(@withaccents, @count, 1), SUBSTRING(@withoutaccents, @count, 1));
        SET @count = @count - 1;
    END WHILE;

    -- SPECIAL CHARS
    SET @special = '«»’”“!@#$%¨&()_+=§¹²³£¢¬"`´{[^~}]<,>.:;?/°ºª+|\''';
    SET @count = LENGTH(@special);
    
    WHILE @count > 0 do
        SET @textvalue = REPLACE(@textvalue, SUBSTRING(@special, @count, 1), '');
        SET @count = @count - 1;
    END WHILE;

    RETURN @textvalue;

END
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DELIMITER ;