java - 有没有办法在 JPA 中使用鉴别器值与实体继承建立双向关系？

Question

我有一个尊贵的客户和订单，我想在 hibernate 状态下建立双向关系。我该怎么做呢？谢谢

@Entity
@Table(name="VCUST")
@DiscriminatorValue("VCUST")
@PrimaryKeyJoinColumns({
    @PrimaryKeyJoinColumn(name="CUST_ID",referencedColumnName="ID"),
    @PrimaryKeyJoinColumn(name="CUST_TYPE",referencedColumnName="TYPE")
})
public class ValuedCustomer extends Customer { 

@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL,orphanRemoval = true)

    @JoinColumn(name = "customer_order", nullable = true)

    private Set<Order> orders = new HashSet<>();

}


@Entity
@Table(name=“Order”)
public class Order { 

@Id
private int id;
}

Answer 1

这很容易。重要的是@OneToMany 中的mappedBy 属性，它指示该关系由Order 实体管理。

@Entity
@Table(name="VCUST")
@DiscriminatorValue("VCUST")
@PrimaryKeyJoinColumns({
    @PrimaryKeyJoinColumn(name="CUST_ID",referencedColumnName="ID"),
    @PrimaryKeyJoinColumn(name="CUST_TYPE",referencedColumnName="TYPE")
})
public class ValuedCustomer extends Customer { 

   @OneToMany(mappedBy= 'valuedCustomer" fetch = FetchType.LAZY, cascade = CascadeType.ALL,orphanRemoval = true)
   private Set<Order> orders = new HashSet<>();

}

@Entity
@Table(name=“Order”)
public class Order { 

   @Id
   private int id;

   @ManyToOne
   private ValuedCustomer valuedCustomer;


}