Magento get popular products by ordered qty

Magento product report resource collection allows you to get most popular products based on different options.

functions we will use: addOrderedQty, setOrder

Let's load this resource collection first like this:

$storeId = Mage::app()->getStore()->getId();
$products = Mage::getResourceModel('reports/product_collection')
     ->addAttributeToSelect('*')
     ->setStoreId($storeId)
     ->addStoreFilter($storeId)
     ->setPageSize(5);

Now, we can pass our filter on the product collection:

$products->addOrderedQty();
// you can pass date range as well
$from = '2013-01-01';
$to = '2013-01-10';
$products->addOrderedQty($from, $to);
$products->setOrder('ordered_qty', 'desc');

Source: app\code\core\Mage\Reports\Model\Resource\Product\Collection.php where addOrderedQty looks like below in magento 1.7.0.2

    /**
     * Add ordered qty's
     *
     * @param string $from
     * @param string $to
     * @return Mage_Reports_Model_Resource_Product_Collection
     */
    public function addOrderedQty($from = '', $to = '')
    {
        $adapter              = $this->getConnection();
        $compositeTypeIds     = Mage::getSingleton('catalog/product_type')->getCompositeTypes();
        $orderTableAliasName  = $adapter->quoteIdentifier('order');
 
        $orderJoinCondition   = array(
            $orderTableAliasName . '.entity_id = order_items.order_id',
            $adapter->quoteInto("{$orderTableAliasName}.state <> ?", Mage_Sales_Model_Order::STATE_CANCELED),
 
        );
 
        $productJoinCondition = array(
            $adapter->quoteInto('(e.type_id NOT IN (?))', $compositeTypeIds),
            'e.entity_id = order_items.product_id',
            $adapter->quoteInto('e.entity_type_id = ?', $this->getProductEntityTypeId())
        );
 
        if ($from != '' && $to != '') {
            $fieldName            = $orderTableAliasName . '.created_at';
            $orderJoinCondition[] = $this->_prepareBetweenSql($fieldName, $from, $to);
        }
 
        $this->getSelect()->reset()
            ->from(
                array('order_items' => $this->getTable('sales/order_item')),
                array(
                    'ordered_qty' => 'SUM(order_items.qty_ordered)',
                    'order_items_name' => 'order_items.name'
                ))
            ->joinInner(
                array('order' => $this->getTable('sales/order')),
                implode(' AND ', $orderJoinCondition),
                array())
            ->joinLeft(
                array('e' => $this->getProductEntityTableName()),
                implode(' AND ', $productJoinCondition),
                array(
                    'entity_id' => 'order_items.product_id',
                    'entity_type_id' => 'e.entity_type_id',
                    'attribute_set_id' => 'e.attribute_set_id',
                    'type_id' => 'e.type_id',
                    'sku' => 'e.sku',
                    'has_options' => 'e.has_options',
                    'required_options' => 'e.required_options',
                    'created_at' => 'e.created_at',
                    'updated_at' => 'e.updated_at'
                ))
            ->where('parent_item_id IS NULL')
            ->group('order_items.product_id')
            ->having('SUM(order_items.qty_ordered) > ?', 0);
        return $this;
    }

And, setOrder looks like this:

 /**
     * Set order
     *
     * @param string $attribute
     * @param string $dir
     * @return Mage_Reports_Model_Resource_Product_Collection
     */
    public function setOrder($attribute, $dir = self::SORT_ORDER_DESC)
    {
        if (in_array($attribute, array('carts', 'orders','ordered_qty'))) {
            $this->getSelect()->order($attribute . ' ' . $dir);
        } else {
            parent::setOrder($attribute, $dir);
        }
 
        return $this;
    }