Customers > Invoices relationship question / troubles
I have a customers table and an invoices table. When I create a new invoice, I enter the customer name and it looks up the customer's address info an populates the fields in the invoice. However if I change the customer's address in the customers table, all of the records in the invoices table get updated as well. This is undesirable because a customer may have moved and I don't want old invoices showing the new address, I want them showing the old address.
Can someone help me understand how to make this work properly?