How to use Optimistic Locking between 3 entities in JAVA

Question

I have the following entities:

@Entity
public class TableA {
    @Id
    @GeneratedValue(...)
    private Long id;
    private Timestamp updatedDateTime;
    @Version
    private int version;
}

@Entity
public class TableB{
    @Id
    @GeneratedValue(...)
    private Long id;

    @ManyToOne
    @JoinColumn(name="fieldTableC")
    private TableC paymentsData;
}

@Entity
public class TableC{
    @Id
    @Column(name = "fieldTableC")
    private String fieldTableC;
    
    private String someOtherField;
}

The problem I am facing, is that I cannot find any information on how to do the following scenario: If either TableB or TableC gets updated, then I need hibernate to automatically increment the version in TableA. Should I add a FK of TableA to TableB & TableC ? As you can see, I already have a @ManyToOne from TableB to TableC, if that helps in any way. PS: I am using JpaRepository

Answer 1

I ended up by adding the child reference in parent, and parent reference into child. Whenever I want to save a child, I also update the parent updatedDateTime value. My method is @Transient, so everything will be saved in 1 transaction.

Also added CascadeType.SAVE_UPDATE, so that when saving parent, the child will also be saved

Eg: Added to TableA:

@OneToMany(mappedBy = "tableA")
@Cascade(org.hibernate.annotations.CascadeType.SAVE_UPDATE)
private List<TableB> list= new ArrayList<>();

Added to TableB:

@ManyToOne
@JoinColumn(name = "tableA_root_id")
private TableA tableA;