get ID for the last invoice of an order

Question

I need the ID of the last invoice for an order. I already have the order ID, but it does not know how to get the ID of the last invoice. Does anyone know how to do it?

Answer 1

One approach:

$order_id = intval($_POST['order_id']);
$order = Mage::getModel('sales/order')->load($order_id);
$invoice = $order->getInvoiceCollection()
    ->addAttributeToSort('created_at', 'DSC')
    ->setPage(1, 1)
    ->getFirstItem();