Problem while execute the Query

Hi,
I have a problem especially executing the query, I hope the problem due to special Character, i am using the ADOB for DB[MYSQL], Language is PHP, i have enclosed the function which make me hazard …….

define('QRY_ALTER_CATEGORY', 'ALTER TABLE Category ADD %s');

 function ChangeCategory($FieldName) {
       $Condition = $FieldName.' VARCHAR(20)';
       $Query = sprintf(QRY_ALTER_CATEGORY,$Condition);
       $this->core->DBConn->Execute($Query);
    }

PHP:

The above Function used to Alter the Table Field name ,the problem is : if the Filed name is "Special character [íóÓéèÉÈÚúáàÁÀãñÑÖöÜüßÉ]” means the query is not execute other wise its works well ,please let me know the solution for the problem ,and expecting positive reply and advance thanks the same.

 

works fine after change the code like

$Condition = '`' . $FieldName. '`' . ' VARCHAR(20)';

 

Why you are using special characters in field names? Is there any specific need?