... tests that can create, read, update, and delete data from our database.To begin database operations, a transaction must begin the initiation CRUD operations, and then commit the transaction:em.getTransaction().begin();// ... (JPDA) in order to broker information from a running virtual machine (VM) and a debugging tool, usually an IDE capable of interacting with the Java Debug Wire Protocol (JDWP) . For More Information: ... class , which takes an order as a parameter, then calls OrderDao with that order, to place the order. The main point is that in isolation, we don't care what actually happens in OrderDao,...