protected function _fromDualIfy($queryString)
    {
        $statement = strtolower(trim($queryString));
        if (strpos($statement, 'select') !== 0 || preg_match('/ from /', $statement)) {
            return $queryString;
        }
        //Doing a SELECT without a FROM (e.g. "SELECT 1 + 1") does not work in Oracle:
        //need to have "FROM DUAL" at the end
        return "{$queryString} FROM DUAL";
    }