public function addOtherSQL($otherSQL)
    {
        if ($otherSQL == null)
            return;
        if ($this->_otherSQL == null)
        {
            $this->_otherSQL = $otherSQL;
        }
        elseif (strpos($this->_otherSQL, $otherSQL) === false)
        {
            $this->_otherSQL .= " AND " . $otherSQL;
        }
    }