magento get only product id and qunatity by order id

Question

I want to get only product id and qty from order id

below is way to get order detail

$order = Mage::getModel('sales/order')->loadByIncrementId($orderId);
$items = $order->getAllItems();

but it gives all i want only product id, quantity to minimize load ,

what filter have i to add ?

Answer 1

You can do this order item collection

Mage::getModel('sales/order_item')->getCollection();

for particular order you can get bu filter of field order_id;

      $orderItems=Mage::getModel('sales/order_item')->getCollection()
->addFieldToFilter('order_id',$orderid);

    foreach($orderItems as $eachorderitem){
    echo $eachorderitem->getQtyOrdered();
    }

Answer 2

Please use addAttributeToSelect();

$orderItems=Mage::getModel('sales/order_item')->getCollection()
                            ->addAttributeToSelect('qty_ordered')
                            ->addFieldToFilter('order_id','2');
                foreach($orderItems as $eachorderitem){
                    echo $eachorderitem->getQtyOrdered();
                }