Chapter 2. Advanced Mapping

In this chapter, we will explore mapping concepts. This is at the core of the Object-Relational Mapping challenge to correctly map Java objects and classes to their persistence representation. As discussed in the previous chapter, the object-oriented world has a lot in common with the relational world, attributes, types, and so on. The ORM solutions, such as Hibernate, were created to address their notable differences, inheritance, composition, object reference and identification, and much more. After reading this chapter, you will be able to correctly map database identification to a class attribute using primitive data types or a more complex Java class. You will also see how to create associations between objects and annotate them correctly so that Hibernate has enough information about the relationships between table data. Furthermore, you will be able to instruct Hibernate to perform cascaded operations and map classes as part of an inheritance model. Finally, you will see how to work with enumerated types and create your own custom type.

In this chapter, we will cover the following topics: