Hello

When importing purchase order lines from a csv or excel file (based on a basket validated on supplier web site for instance)  

I need to make sure 

a) that the import in my odoo db  DOES NOT CREATE a new product IF THE PRODUCT ALREADY EXISTS IN THE DB but creates the PO lines for the existing products (supplier/quantity/prices...) 

b) OR that the import process creates a new product IF THE PRODUCT DOES NOT  EXIST IN THE DB AND THEN creates the PO lines for the existing products (supplier/quantity/prices...) 

The solution that seems to be used is to add the product_id data to the purchase order lines of the csv file created from the supplier basket

Then How would you  obtain the list of odoo product_id

based on the reference ordered to the supplier?

Any recommendation except new module as I am using a Saas contract?

Thanks in advance