Fatal error: Call to a member function getId() on a non-object in C:\wamp\www\magentno\lib\Varien\Data\Tree\Dbp.php on line 332

Question

I am working with Magento 1.8.0.0, I have a test version installed on a WAMP server via localhost and when I want to add category's i get the next error:

Fatal error: Call to a member function getId() on a non-object in C:\wamp\www\magentno\lib\Varien\Data\Tree\Dbp.php on line 332

i have not made a store yet because i need category's for that.

I have already added a try and catch code to the line that gives the error.

this is the code that gives the error:

    public function loadEnsuredNodes($category, $rootNode)
{
    $pathIds = $category->getPathIds();
    $rootNodeId = $rootNode->getId();
    $rootNodePath = $rootNode->getData($this->_pathField);

    $select = clone $this->_select;
    $select->order($this->_table.'.'.$this->_orderField . ' ASC');

    if ($pathIds) {
        $condition = $this->_conn->quoteInto("$this->_table.$this->_idField in (?)", $pathIds);
        $select->where($condition);
    }

    $arrNodes = $this->_conn->fetchAll($select);

    if ($arrNodes) {
        $childrenItems = array();
        foreach ($arrNodes as $nodeInfo) {
            $nodeId = $nodeInfo[$this->_idField];
            if ($nodeId<=$rootNodeId) {
                continue;
            }

            $pathToParent = explode('/', $nodeInfo[$this->_pathField]);
            array_pop($pathToParent);
            $pathToParent = implode('/', $pathToParent);
            $childrenItems[$pathToParent][] = $nodeInfo;
        }

        $this->_addChildNodes($childrenItems, $rootNodePath, $rootNode, true);
    }
}

this line is the killer:

 $rootNodeId = $rootNode->getId();

Answer 1

This problem occurs due to reindexing problem. You can run this query in order to solve this problem

INSERT INTO catalog_category_entity(entity_id,entity_type_id,attribute_set_id,parent_id,created_at,updated_at,path,POSITION,level,children_count) VALUES (1,3,0,0,'0000-00-00 00:00:00','2009-02-20 00:25:34','1',1,0,1),(2,3,3,0,'2009-02-20 00:25:34','2009-02-20 00:25:34','1/2',1,1,0); INSERT INTO catalog_category_entity_int(value_id,entity_type_id,attribute_id,store_id,entity_id,value) VALUES (1,3,32,0,2,1),(2,3,32,1,2,1); INSERT INTO catalog_category_entity_varchar(value_id,entity_type_id,attribute_id,store_id,entity_id,value) VALUES (1,3,31,0,1,'Root Catalog'),(2,3,33,0,1,'root-catalog'),(3,3,31,0,2,'Default Category'),(4,3,39,0,2,'PRODUCTS'),(5,3,33,0,2,'default-category');

Note:- answer taken from This Link