Spring Data Rest merge data on relationship update

I am using Spring Data REST in my project and I have a relationship issue while editing the main entity. This is a simple version of my model:

@MappedSuperclass
public abstract class AbstractEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    // Getters and setters
}

@Entity
public class Player extends AbstractEntity {

    private String category;

    private String fnuCode;

    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinTable(name = "player_contact", joinColumns = @JoinColumn(name = "id_player"), inverseJoinColumns = @JoinColumn(name = "id_contact"))
    private List<Contact> contacts;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "id_person")
    private Person person;

    // Getters and setters
}

@Entity
public class Contact extends AbstractEntity {

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "id_person")
    private Person person;

    private String relationship;

    // Getters and setters
}

@Entity
public class Person extends AbstractEntity {

    private String name;

    private String lastname;

    private String idCard;

    // Getters and setters
}

      

        
        
        
      

    

Then I have my PlayerRepository :

@RepositoryRestResource(path = "players", excerptProjection = PlayerList.class)
@CrossOrigin(origins = "http://localhost:8081")
public interface PlayerRepository extends PagingAndSortingRepository<Player, Long> {

}

      

        
        
        
      

    

PlayerDetail is the projection I use when viewing and editing the player:

@Projection(name = "playerdetail", types = { Player.class })
public interface PlayerDetail {

    @Value("#{target.person.name} #{target.person.lastname}")
    String getFullName();

    @Value("#{target.person.idCard}")
    String getIdCard();

    @Value("#{target.category}")
    String getCategory();

    @Value("#{target.fnuCode}")
    String getFnuCode();

    List<Contact> getContacts();
}

      

        
        
        
      

    

I do not have a repository for contacts as they are created and modified in the context of the player.

This is an example json response . I get when I want to edit or see player details (object is created from player projection):

{
 "idCard" : "12365478",
 "fnuCode" : "1111",
  "contacts" : [ {
    "person" : {
      "name" : "Roberto",
      "lastname" : "Perez",
      "idCard" : null
    },
    "relationship" : "Father"
  }, {
    "person" : {
      "name" : "Lucia",
      "lastname" : "Perez",
      "idCard" : null
    },
    "relationship" : "Sister"
  } ],
  "fullName" : "Juancito Perez",
  "category" : "U19",
  "_links" : {
    "self" : {
      "href" : "http://localhost:8080/players/171"
    },
    "jugador" : {
      "href" : "http://localhost:8080/players/171{?projection}",
      "templated" : true
    }
  }
}

      

        
        
        
      

    

The problem occurs when I edit the player and delete the first contact from the list, in this case "Roberto Perez". As a result, the Lucia Perez row in the database is deleted and its data is merged into the Roberto Perez row. Before deleting the first contact, I have the following data in the DB:

Table: contact
id  |id_person  |relationship   |
175 |176        |Father         |  --> First contact (Roberto)
178 |179        |Sister         |  --> Second contact (Lucia)

Table: person
id  |id_card    |lastname   |name
176 |null       |Perez      |Roberto
179 |null       |Perez      |Lucia

      

        
        
        
      

    

After deleting the first contact (Roberto), I have the following:

Table: contact
id  |id_person  |relationship
175 |176        |Sister

Table: person
id  |id_card    |lastname   |name
176 |null       |Perez      |Lucia

      

        
        
        
      

    

Please note that the ID for the second contact has changed . It should be 178 instead of 175.

EXPECTED RESULT :

Table: contact
id  |id_person  |relationship
178 |179        |Sister 

Table: person
id  |id_card    |lastname   |name
179 |null       |Perez      |Lucia

      

        
        
        
      

    

The second contact must contain its ID.

I suppose Spring Data REST is merging contact information because there is no one-to-one way to identify each contact as the ID is not projected.

I need a way to prevent merging contacts. Is there any other way to manage collections and relationships in Spring Data REST?