And where/how does this fail for you?
What exactly do you mean by "all the products that we ordered from our suppliers"?
That would seem to be a case of simply going to a layout based on products and selecting show all records so I think you want something a bit different than that.
Most systems for handling PO's use more tables than what you have here. Usually there is a table of purchase orders, a line items table and a products table listing all products that you might order from your suppliers. A suppliers table would be a fourth table in such a set up.