Question

我在BD中有表MOBILE和VESSEL。他们之间存在着传承的关系。 MOBILE是父级，VESSEL有一个具有相同ID的外键。

在Java中我有两个类：

@Entity
public class Mobile implements Serializable, ITechnicalBO {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    @OneToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "id")
    private Vessel vessel;

{.................}

}


@Entity
public class Vessel implements java.io.Serializable, ITechnicalBO {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    @OneToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "id")
    private Mobile mobile;

{.................}

}

我需要很好地声明id。我通过互联网找到了很多类似的主题，但我无法解决我的问题。

我是如何真正声明要向Hibernate声明的id必须生成VESSEL的id来分配MOBILE的id？

感谢您的帮助。

Answer 1

你说Mobile是父母，所以Vessel应该扩展Mobile：

@Entity
@PrimaryKeyJoinColumn(name = "id_vessel", referencedColumnName = "id_mobile")
public class Vessel extends Mobile implements java.io.Serializable {

    @Column(name="id_vessel", insertable =  false, updatable = false)
    private Integer id;
    // Vessel inherits all the fields from Mobile. You can add some if you want.
}

@Entity
@Inheritance(strategy=InheritanceType.JOINED)
public class Mobile implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="id_mobile")
    private Integer id;

    // Some fields
}

遗产在冬眠中的遗产

1 个答案: