Which annotation is used to automatically generate primary key values in JPA?

Java MCQ: Which annotation is used to automatically generate primary key values in JPA?

Answer:

Explanation:

The @GeneratedValue annotation is used in JPA to automatically generate primary key values. This annotation is applied to the primary key field of an entity and allows the database or JPA provider to generate a unique identifier for each new entity instance.

Here’s an example:

@Entity
public class Employee {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    // Getters and setters
}

In this example, the id field is annotated with both @Id and @GeneratedValue, indicating that it is the primary key and its value will be automatically generated by the database using the IDENTITY strategy.

Using @GeneratedValue simplifies the process of assigning primary key values and ensures uniqueness for each entity instance.

Reference links:

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