java - 如何将一对一 hibernate 实体映射到一对多数据库结构？

Question

我正在尝试做一个一对一的双向 hibernate 实体。当我保存父对象时，它没有填写子对象上的 customer_id。我不知道为什么。我希望有某种方法可以通过 hibernate 注释告诉它执行此操作。

我的实体看起来像

@Table(name = "customer")
public class CustomerEntity {

    @Id
    @Column(name = "id")
    private Long id;

    @OneToOne(mappedBy = "customer", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    private CustomerAddressEntity customerAddress;

    ..more
}

和

@Table(name="customer_address")
@GenericGenerator(name="generator", strategy="increment")
public class CustomerAddressEntity {

    @Id
    @Column(name = "id")
    @GenericGenerator(name = "sequence_customer_address_id", strategy = "com.abc.enrollment.service.IdGenerator")
    @GeneratedValue(generator = "sequence_customer_address_id")
    private Long id;

    @OneToOne
    @JoinColumn(name = "customer_id", referencedColumnName = "id")
    private CustomerEntity customer;

    ..more
}

表格看起来像

CREATE TABLE enroll.customer_address(
id                 NUMBER(38,0) NOT NULL,
customer_id        NUMBER(38,0) )

CREATE TABLE enroll.customer (
id                 NUMBER(38,0) NOT NULL)

hibernate 版本 = "5.0.0.CR2"

---

除了已接受的答案外，我还必须做一些其他事情才能让它发挥作用。我会把它贴在这里以防它帮助别人。我们使用 lombok 并对对象进行 JSON 序列化。以下注释避免了堆栈溢出错误。

@ToString(exclude = "customer")
@EqualsAndHashCode(exclude = "customer")
public class CustomerAddressEntity {

和

@JsonIgnore
private CustomerEntity customer;

Answer 1

既然是双向关系，就应该在两端都设置。意思是，在parent中设置对子对象的引用，在child中设置对父对象的引用。它应该工作。像这样

Customer cust = new Customer();
CustomerAddress custAddr = new CustomerAddress();
cust.setCustomerAddress( custAddr );
custAddr.setCustomer( cust );