I am building a java application for my final project. The java application is connected to a Microsoft Access Database. The database includes the following tables:
The project is an Order Processing System?
Customer, Invoice, Invoice_Detail, Orders, Order_Detail, Parts, Payments, Sales_Rep, Security_Login,Territory, Vendor_Info, Vendor_Parts.

I have some questions on it.

When an Orders placed which tables/fields need to be updated?
when a payment is made which tables/fields need to be updated?
when an invoice is created which tables/fields need to be updated if any?

If anyone has ever done something like this let me know what to do.

Thank you