java - 有没有办法与实体继承建立双向关系。在 JPA 中加入判别器值？

Question

我有一个 ValuedCustomer 和 Order，我想在 hibernate 中建立双向关系。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 realtionship 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;


}