What does the @Inheritance annotation in JPA specify?

Java MCQ: What does the @Inheritance annotation in JPA specify?

Answer:

Explanation:

The @Inheritance annotation in JPA specifies the inheritance strategy to be used for entity classes that inherit from a common superclass. JPA supports different inheritance strategies, such as SINGLE_TABLE, JOINED, and TABLE_PER_CLASS, which determine how the entity data is mapped to the underlying database tables.

Here’s an example of using @Inheritance:

@Entity
@Inheritance(strategy = InheritanceType.JOINED)
public class Employee {
    @Id
    private Long id;

    private String name;

    // Getters and setters
}

@Entity
public class Manager extends Employee {
    private String department;

    // Getters and setters
}

In this example, the Employee class is the base class, and the Manager class extends it. The @Inheritance(strategy = InheritanceType.JOINED) annotation specifies that the inheritance strategy is JOINED, meaning that each subclass will have its own table, and the primary key will be shared across the tables.

The @Inheritance annotation is essential for managing inheritance hierarchies in JPA and determining how data is stored in the database.

Reference links:

https://www.rameshfadatare.com/learn-java-programming/
https://www.javaguides.net/p/java-tutorial-learn-java-programming.html