Relating TOs, a simple question on good practise.
Ι am relating an invoice table via Client_Id and Shop_Id (in a scenario where many shops issue invoices) and I have to do this via a TO of the invoice table, which takes up the second relation to shop_id.
My question is this, in my invoices layout, based on the Invoice Table (and not its second TO) I chose to substitute the Shop_Id field with a ::Shop_Id field from the TO of invoices, since this is related to the shops table.
Is what I did superfluous? It's the same field anyway. Should I keep the one on the first Invoice table?