[FIXED] JPA update parent child

Issue

I have 2 object person and address. person is parent and address is child.

• Person : personPK , status
• Address : addressPK , person_fk, status

My repository is extending JPARepository. personRepository.save(person); is working fine for insert. But when I update the person object by updating status(eg: Active) in both the tables and use personRepository.save(person); My foreign key references(person_fk) is set as null.

My parent class :

@Entity
@DynamicUpdate
@Table(name = "person")
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="person_pk", nullable=false)
    private Long personPK;
    @OneToMany(fetch = FetchType.EAGER, mappedBy = "person",cascade = CascadeType.PERSIST)
    private Set<Address> addresses = new HashSet<>();
    ...
}

And my child class :

@Entity
@DynamicUpdate
@Table(name = "address")
public class Address {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "address_pk")
    private Long addressPK;
    @ManyToOne
    @JoinColumn(name = "person_fk", referencedColumnName = "person_pk", nullable=false)
    private Address address;
    ...
}

And from my service layer I am updating it using : personRepostiry.save(person);

Any help what I am doing wrong here?

Solution

Firstly Change:

@ManyToOne
@JoinColumn(name = "person_fk", referencedColumnName = "person_pk", nullable=false)
private Address address;

to:

@ManyToOne(targetEntity = Person.class)
@JoinColumn(name = "person_fk", referencedColumnName = "person_pk", nullable = false)
private Person person;

then change:

@OneToMany(fetch = FetchType.EAGER, mappedBy = "person",cascade = CascadeType.PERSIST)
private Set<Address> addresses = new HashSet<>();

to:

@OneToMany(fetch = FetchType.EAGER, mappedBy = "person", cascade = {CascadeType.PERSIST, CascadeType.MERGE})
private Set<Address> addresses = new HashSet<>();

and add this to your Person class:

public void addAddress(Address address) {
    address.setPerson(this);
    addresses.add(address);
}

then use:

person.addAddress(address);
persist(person)

or

merge(person);

Answered By - Roham Amini
Answer Checked By - Marie Seifert (JavaFixing Admin)