Hibernate 一对一映射，外键为 NULL

Question

This is my first attempt to map with One to One relation. I have the following entities:

@Entity
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Client {

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

    @Size(max = 100)
    private String name;

    @Email(message = "Email should be valid")
    private String email;

    @OneToOne
    @PrimaryKeyJoinColumn
    private Key key;
}

AND

@Entity
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Key {

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

    @Column(unique = true)
    private UUID number;

    @OneToOne
    private Client client;

    public Key(UUID number) {
        this.number = number;
    }
}

They do not see each other, I get NULL in the foreign key section. There is a solution when using the EntityManager class in the following post:

JPA / Hibernate OneToOne Null in foreign key

Unfortunately, that method doesn't work for me.

Database snapshot:

Thank you for the answers!

Answer 1

We don't need to mention the @PrimaryKeyJoinColumn annotation. When we are mapping the tables it will create primary key and foreign key. We just need to map properly.
In the Client model class you have to create the mapping like below

    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "key_id", referencedColumnName = "id")
    private Key key;

and in the Key model class like this

    @OneToOne(mappedBy = "key")
    private Client client;