spring-boot - 是否有可能通过值对象引用另一个类

Question

如何进行从 RoomOccupancy 的stayId 到 Stay 的stayId 的多对一 xml 映射。请注意，StayId 是一个值对象，因此它不包含对 Stay 的整个引用。

 public class RoomOccupancy {
// generated hibernate id
private Long id;
private LocalDate startDate;
private LocalDate endDate;
private StayId stayId;
}


public class Stay {
// generated hibernate id
private Long id;
private StayId stayId;
}

如果有人可以帮助我，我会很高兴。在此先感谢您！

Answer 1

如果我理解你，那么你需要这样做：

public class RoomOccupancy {
private Long id;
private LocalDate startDate;
private LocalDate endDate;
@ManyToOne(fetch = FetchType.EAGER, targetEntity = Stay .class)
    @JoinColumn(name = "stayId")
    private Stay stay;
}    

public class Stay {
private Long id;
}

或者，如果您需要 xml，只需将下一个代码添加到您的 xml 文件

<many-to-one name = "stay" column = "stayId" class="Stay " not-null="true"/>