Hmm... You want to save product`s stock information in order_product table?
So first you must to add custom field in oc_order_product
ALTER TABLE `oc_order_product` ADD `stock_status` INT(11) NOT NULL AFTER `reward`;
Then in catalog/controller/checkout/confirm.php in $order_data['products'][] = array( You must add key - stock_status
'stock' => $this->model_catalog_product->getProduct($product['product_id'])['stock_status'],
So we modified our controller in customer side, and now our data receive the stock_status.
After receive products data from customer side, we must save in oc_order_table
Open path - catalog/model/checkout/order.php and edit addOrder function... After reward = '" . (int)$product['reward'] . "'
in products loop add after comma:
stock_status = '" . $this->db->escape(product['stock_status']) . "'
I write an example, how to save data from customer side about product stock data.