I'm trying to get which table saves the Related Products for items and order-items? Is there any way to know how many items sold by these property. I try to check this table sales_order_item but I don't find anything?
Currently there is no table which saves the data to check if a products was added through cross-sell or up-sell property.
But for related products, the information is stored in product_options column of sales_order_item table. You can find related_product key in the json of info.
