Pro JPA 2 in Java EE 8: An In-Depth Guide to Java Persistence APIs

© Mike Keith, Merrick Schincariol, Massimo Nardone 2018

Mike Keith, Merrick Schincariol and Massimo NardonePro JPA 2 in Java EE 8https://doi.org/10.1007/978-1-4842-3420-4_4

4. Object-Relational Mapping

Mike Keith¹ , Merrick Schincariol² and Massimo Nardone³

(1)

Ottawa, Ontario, Canada

(2)

RR 3, RR 3, Almonte, Ontario, Canada

(3)

Helsinki, Finland

 

The largest part of an API that persists objects to a relational database ends up being the object-relational mapping (ORM) component. The topic of ORM usually includes everything from how the object state is mapped to the database columns to how to issue queries across the objects. We are focusing this chapter primarily on how to define and map entity state to the database, emphasizing the simple manner in which ...