Get a Magento product collection without sub-products of configurable products

Question

I want to get a list of all products available in my Magento installation. Currently I am using the following call to filter out enabled products and limit the result set to those products which are visible both in catalog and search results:

$products = \Mage::getResourceModel('catalog/product_collection')
    ->addAttributeToFilter('status', \Mage_Catalog_Model_Product_Status::STATUS_ENABLED)
    ->addAttributeToFilter('visibility', array('in' => array(
        \Mage_Catalog_Model_Product_Visibility::VISIBILITY_IN_SEARCH,
        \Mage_Catalog_Model_Product_Visibility::VISIBILITY_BOTH,
    )))
    ;

As all children of configurable products are stored as regular products they show up in the resulting collection. However, I don't want them to be included. Is there any way to safely achieve this?

In case you wonder about all these backslashes: My code runs in an PHP-5.3 compatible environment using namespaces so I had to refer to the global namespace when calling Magento functions.

Thanks in advance,

Edit (further explanation of what I want to achieve):

My employer develops an own eCommerce system. This software provides a mechanism similar to Magento's configurable products. All sub-products assigned to a configurable product know about their parent (indicated by the parent's primary key). Hence, it it easy to filter them out by excluding product rows having a non-zero parent ID.

How is this realized in Magento? Don't the sub products know which configurable product they are assigned to?

Answer 1

Figured it out by myself. The table catalog_product_relation contains information about parent-child relationships for configurable products. I just had to join the table to my collection and look for product records that do not have a corresponding row in catalog_product_relation with their entity_id as child_id. Quite simple if you know what you have to do.

    $products = Mage::getResourceModel('catalog/product_collection')
        ->joinTable('catalog/product_relation', 'child_id=entity_id', array(
            'parent_id' => 'parent_id'
        ), null, 'left')
        ->addAttributeToFilter(array(
            array(
                'attribute' => 'parent_id',
                'null' => null
            )
        ));

Answer 2

Try adding

->addAttributeToFilter('visibility', array(
        'neq' => Mage_Catalog_Model_Product_Visibility::VISIBILITY_NOT_VISIBLE))

See /app/code/core/Mage/Catalog/Model/Api2/Product/Rest.php

/**
 * Retrieve list of products
 *
 * @return array
 */
protected function _retrieveCollection()
{

  ....
  ->addAttributeToFilter('visibility', array(
        'neq' => Mage_Catalog_Model_Product_Visibility::VISIBILITY_NOT_VISIBLE))

See Magento SQL query: Get all simple products that are “not visible individually”