如何在Hibernate中创建多级继承策略

Question

当我只有product类和两个用继承策略扩展product的类时，单表（product-

必须在根实体中定义鉴别器列，它将在子类com中被忽略。实例演示。实体电子学

产品类别

@Data
@AllArgsConstructor
@NoArgsConstructor
@Entity
@DiscriminatorColumn(name = "type")
public abstract class Product {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

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

    @Column(name = "basic_characteristics")
    private String basicCharacteristics;

    @Column(name = "price")
    private Integer price = 0;
    }

电子类：

@AllArgsConstructor
@NoArgsConstructor
@Data
@Entity
@DiscriminatorValue("electronics")
@DiscriminatorColumn(name = "typeElectronics")
public class Electronics extends Product {

    @Column(name = "electronics_data")
    private String electronicsData;
}

智能手机类别：

@AllArgsConstructor
@NoArgsConstructor
@Entity
@Data
@DiscriminatorValue("smartphone")
public class Smartphone extends Electronics{

    @Column
    private String smartphoneInfo;
}

我想把电子学课分成两个不同领域的实体。

Answer 1

https://docs.oracle.com/javaee/7/api/javax/persistence/DiscriminatorColumn.html

策略和鉴别器列仅在应用了不同继承策略的实体类层次结构或子层次结构的根中指定

根据留档，我不认为此示例中的Electronics类可以为其子类添加额外的鉴别器列。