避免JPA抽象类的额外表

Question

@Entity
@Inheritance(strategy = InheritanceType.JOINED)
abstract class Employee {
    @Id
    private Long id;

    private String firstName;
    private String secondName;
}

@Entity
abstract class ProjectManager extends Employee {
    @OneToMany(mappedBy="manager")
    private List<Developer> developers;
}


@Entity
abstract class Developer extends Employee {
    @ManyToOne
    @JoinColumn(name="project_manager_id")
    private ProjectManager manager;
}

@Entity
class JavaProjectManager extends ProjectManager {
    private String someCustomProperty;
}

@Entity
class JavaDeveloper extends Developer {
    private String skill;
}

此外，我不想将开发人员从ProjectManager转移到JavaProjectManager，因为我有更多从ProjectManager扩展的类，需要开发人员。

Answer 1

TABLE_PER_CLASS完全符合您的要求。

此类型仅为非抽象表创建/使用表。

请在此处阅读有关各种类型的更多信息：