Java Hibernate:insertable=false&；的有趣测验；可更新=错误

我所拥有的：

多个

所有者

实体，其中包含一个

客户

子类型实体。我需要每个客户端实体的子类型只能保存到数据库中一次，所以我使用

insertable=false，updateable=false

@Entity
@Table(name = "Client")
public class Client implements Serializable {

    @Id
    @Column(name = "id")
    private String id = this.getClass().getSimpleName();

    @Column(name = "firstName")
    private String firstName;

    //getters & setters
}

@Entity
@Table(name = "Client")
public class AngryClient extends Client {
}

@Entity
@Table(name = "Client")
public class SilentClient extends Client {
}

@Entity
@Table(name = "Owner")
public class Owner {

    @Id
    @SequenceGenerator(name = "sequence", sequenceName = "_vacancy")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequence")
    @Column(name = "id")
    private int id;

    @ManyToOne
    @JoinColumn(name = "id", insertable = false, updatable = false)

     //getters & setters
}

我抓不住的东西：

由于

insertable=false，updateable=false

，当我们保存所有者时，客户端将不会被保存。它可以很容易地在数据库中进行检查。

owner

表中存储的唯一列是

id

那么Hibernate如何知道哪个

客户端

对应于哪个

所有者

Session session = sessionFactory.openSession();
session.beginTransaction();

Owner owner1 = new Owner();
Owner owner2 = new Owner();
Client client1 = new AngryClient();
Client client2 = new SilentClient();
owner1.setClient(client1);
owner2.setClient(client2);
session.save(owner1); //client1 isn't saved
session.save(owner2); //client2 isn't saved
int owner1Id = owner1.getId();
session.getTransaction().commit(); //client table is empty

Session session1 = sessionFactory.openSession();
Owner owner = (Owner) session1.get(Owner.class, owner1Id);
System.out.println(owner.getClient());  //HOW DOES IT WORK?! (owner.getClient() returns me AngryClient)

问题：

---

它是如何工作的？或者当我们执行

session.get（Owner.class，owner1Id）

时，Hibernate如何填充客户端文件？

对不起，在

session1.get（Owner.class，owner1Id）

中出错（我使用了session而不是session1）。请关闭此问题您可以自己关闭此问题，单击“关闭”按钮我已经投票关闭此问题。但据我所知，这需要五票。奇怪的是，我通常可以删除我自己的帖子