What does the @OneToMany annotation represent in JPA?

What does the @OneToMany annotation represent in JPA?

Answer:

Explanation:

The @OneToMany annotation in JPA is used to define a relationship where one entity is associated with many entities. This annotation is commonly used to represent relationships like “one department has many employees” or “one customer has many orders.”

For example:

@Entity
public class Department {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;

    @OneToMany(mappedBy = "department")
    private List<Employee> employees;

    // Getters and setters
}

In this example, the Department entity has a @OneToMany relationship with the Employee entity, meaning that one department can have many employees. The mappedBy attribute is used to specify the field in the Employee entity that owns the relationship.

The @OneToMany annotation is essential for modeling complex relationships between entities in a relational database, ensuring that the associations are correctly mapped and managed by JPA.

Reference links:

Spring Data JPA Tutorial