protected function _getCatAdd($aChosenCat)
    {
        $sCatAdd = null;
        if (is_array($aChosenCat) && count($aChosenCat)) {
            $oDB = \OxidEsales\Eshop\Core\DatabaseProvider::getDb();
            $sCatAdd = " and ( ";
            $blSep = false;
            foreach ($aChosenCat as $sCat) {
                if ($blSep) {
                    $sCatAdd .= " or ";
                }
                $sCatAdd .= "oxobject2category.oxcatnid = " . $oDB->quote($sCat);
                $blSep = true;
            }
            $sCatAdd .= ")";
        }

        return $sCatAdd;
    }