Hibernate Springboot JPA类继承问题

我有两类：个人和员工。
员工源于人。Person不是抽象的，可能是连字实体。

人员表：id（主键）、名、姓

员工表：员工id（PK）、人员id（FK）、工作开始日期

这些类如下所示：

人员类别：

@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "persons")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name="first_name")
    private String firstName;

    @Column(name="last_name")
    private String lastName;

    public Person() {
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
}

@Entity
@Table(name = "employees")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
@PrimaryKeyJoinColumn(name = "person_id")
public class Employee extends Person {
    @Id
    @Column(name = "employee_id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long employeeId;

    @Column(name = "start_work_date")
    private Date startDate;

    public Employee() {
    }

    public Long getEmployeeId() {
        return employeeId;
    }

    public void setEmployeeId(Long employeeId) {
        this.employeeId = employeeId;
    }

    public Date getStartDate() {
        return startDate;
    }

    public void setStartDate(Date startDate) {
        this.startDate = startDate;
    }
}

员工类别：

@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "persons")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name="first_name")
    private String firstName;

    @Column(name="last_name")
    private String lastName;

    public Person() {
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
}

@Entity
@Table(name = "employees")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
@PrimaryKeyJoinColumn(name = "person_id")
public class Employee extends Person {
    @Id
    @Column(name = "employee_id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long employeeId;

    @Column(name = "start_work_date")
    private Date startDate;

    public Employee() {
    }

    public Long getEmployeeId() {
        return employeeId;
    }

    public void setEmployeeId(Long employeeId) {
        this.employeeId = employeeId;
    }

    public Date getStartDate() {
        return startDate;
    }

    public void setStartDate(Date startDate) {
        this.startDate = startDate;
    }
}

还有我的寄托：

public interface EmployeeRepository extends JpaRepository<Employee, Long> {
}

public接口EmployeeRepository扩展了JpaRepository{
}

当我调用get of employees时，employees成员本身已填充，但我的所有超类（Person）成员都为空。。。

---

我必须将FK成员添加到员工类别中吗？

是否有理由选择继承而不是组合（与

员工

和

人员

之间的关系）？正如我所读到的，使用InheritanceType.JOINED策略，员工不得拥有自己的id，因为带个人的comon id是加入标准，但在组织中，您有您的id和员工编号。。。组合是可能的，但在面向对象中，员工对个人的继承关系是有意义的。一对一毫无意义。继承是正确的，但是从子类中删除id。是否可以将员工id作为pk保留在db表中，或者也应该删除它？