One of the main goals of JPA was that it should be simple to use and easy to understand. Although its problem domain cannot be trivialized or watered down, the technology that enables one to deal with it can be straightforward and intuitive. In this chapter, we will show how effortless it can be to develop and use entities.
We will start by describing the basic characteristics of entities. We'll define what an entity is and how to create, read, update, and delete it. We'll also introduce entity managers and how they are obtained and used. Then we'll take a quick look at queries and how to specify and execute a query using the
Query objects. The chapter will conclude by showing a simple working application ...