I am testing out the order import option so we can migrate from Magento. I was able to import the orders but not the order details. In Magento I have an Order ID along with most of the other fields, however to be able to import order products you need to have an Item ID. This item_id seems to be a hash generated with session and product information.
I have tried using a random number but the import fails with an “object not found”. If I edit the orders from the admin and add the product, the items are added without a problem, but doing this for 800 orders is quite a waste of time.
Has anyone had experience importing product orders and if so, how did you manage to get the Item ID field? I really appreciate help with this.
Bummer 
I wanted to import all the 1x version cart upgraded to version 2 recently but going to be forced to have the customers login on the old page for old orders.