Entity Mapping & Relationships In Spring Data JPA Mock Test

Question 1: DATA JPA - @OneToOne Mapping

Which of the following best describes a @OneToOne relationship in JPA?

Question 2: DATA JPA - Code Snippet (@OneToMany)

What does the following mapping represent?

@Entity
public class Department {
    @Id
    private Long id;

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

Question 3: DATA JPA - @ManyToOne Mapping

In JPA, what is the typical use of @ManyToOne annotation?

Question 4: DATA JPA - Code Snippet (@ManyToMany)

What is the effect of the following mapping?

@Entity
public class Student {
    @ManyToMany
    @JoinTable(
        name = "student_course",
        joinColumns = @JoinColumn(name = "student_id"),
        inverseJoinColumns = @JoinColumn(name = "course_id")
    )
    private List<Course> courses;
}

Question 5: DATA JPA - Cascade Types

Which cascade type ensures that when a parent entity is removed, its related child entities are also deleted?

Question 6: DATA JPA - Code Snippet (FetchType.LAZY vs EAGER)

What is the default fetch type for a @OneToMany relationship in JPA?

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

Question 7: DATA JPA - Bidirectional Relationships

In a bidirectional relationship, why is the mappedBy attribute important?

Question 8: DATA JPA - Orphan Removal

What happens when orphanRemoval = true is set on a relationship?

Question 9: DATA JPA - Code Snippet (JoinColumn)

What will the following mapping create?

@Entity
public class Employee {
    @ManyToOne
    @JoinColumn(name = "dept_id")
    private Department department;
}

Question 10: DATA JPA - Unidirectional vs Bidirectional

Which statement correctly distinguishes between unidirectional and bidirectional entity relationships?