TreeBehavior::parentIds PHP Method

    public function parentIds()
    {
        $owner = $this->getOwner();
        $db = $owner->getDbConnection();
        $query = 'SELECT ' . $this->idAttribute . ' as owner, (' . 'SELECT id FROM ' . $owner->treeTable() . ' AS t2 ' . 'WHERE t2.' . $this->leftAttribute . ' < t1.' . $this->leftAttribute . ' AND t2.' . $this->rightAttribute . ' > t1.' . $this->rightAttribute . ' ORDER BY t2.' . $this->rightAttribute . ' - t1.' . $this->rightAttribute . ' ASC LIMIT 1)' . ' AS parent' . ' FROM ' . $owner->treeTable() . ' AS t1' . ' WHERE t1.' . $this->idAttribute . ' = ' . $db->quoteValue($owner->id);
        $res = $db->createCommand($query)->query();
        $ids = array();
        foreach ($res as $r) {
            if ($r['parent'] != null) {
                $ids[] = $r['parent'];
            }
        }
        return $ids;
    }