Chapter 3

1. ORM is a technique that allows you to fetch and manipulate data from a database using an object-oriented programming paradigm. JPA provides object-relational mapping for Java developers. Hibernate is a Java-based JPA implementation.
2. The entity class is just a standard Java class that is annotated with the @Entity annotation. You have to implement constructors, fields, getters and setters inside the class. The unique ID field(s) are annotated with the @Id annotation.
3. You have to create a new interface that extends the Spring Data CrudRepository interface. You define the entity and the type of the id field in the type arguments—for example, <Car, Long>.
4. The CrudRepository provides all CRUD operations to your entity. You can create, read, update, and delete your entities using the CrudRepository.
5. You have to create entity classes and link the entities using the @OneToMany and @ManyToOne annotations.
6. You can add demo data to your main application...