java - Hibernate 继承 - OneToMany 与 2 类扩展父不起作用

Question

我有 3 个实体:

@Data
@AllArgsConstructor 
@Entity 
@Table(name = "beneficiary") 
@Inheritance 
@DiscriminatorColumn(discriminatorType = DiscriminatorType.STRING, name = "type") 
public abstract class Beneficiary {   
    public Beneficiary() {}

      @Id private String id;

      private String description; 
}


@Data
@Entity
@DiscriminatorValue("company")
@EqualsAndHashCode(callSuper = true)
public class BeneficiaryCompany extends Beneficiary {
  public BeneficiaryCompany() {
    super();
  }

  public BeneficiaryCompany(String id, String description) {
    super(id, description);
  }
}


@Data
@Entity
@DiscriminatorValue("person")
@EqualsAndHashCode(callSuper = true)
public class BeneficiaryPerson extends Beneficiary {
  public BeneficiaryPerson() {}

  public BeneficiaryPerson(String id, String description) {
    super(id, description);
  }
}

在另一个类中，我想要 2 个独立的集合:

@Data
@AllArgsConstructor
@Entity
@Table(name = "transaction")
public class Transaction {

  public Transaction() {}

  @Id private String id;

  private String description;

  @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true, targetEntity = BeneficiaryCompany.class)
  @JoinColumn(name = "transaction_id", nullable = false)
  private Set<BeneficiaryCompany> beneficiaryCompanies;

  @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true,targetEntity = BeneficiaryPerson.class)
  @JoinColumn(name = "transaction_id", nullable = false)
  private Set<BeneficiaryPerson> beneficiaryPeople;
}

问题是每个 Beneficiary 都被提取到 beneficiaryCompanies 中，而 beneficiaryPeople 在调试器中告诉我:

Unable to evaluate the expression Method threw 'org.hibernate.WrongClassException' exception.

数据库记录看起来不错(已创建 DiscriminatorColumn)。可能是什么问题呢？为什么 beneficiaryCompanies 包含 BeneficiaryPerson 对象？

@编辑:为了获取记录，我使用了 SpringData JPA 存储库。

Answer 1

Use @MappedSuperclass on your base class Beneficiary

Alexandar Petrov 完全正确。您必须删除 @Entity 因为父类(super class)不是实体。在处理扩展类的继承时，您可以在基类上使用 @MappedSuperclass 注释，在您的情况下，它是 Beneficiary。

编辑: This是一篇很好的文章，您可以引用。