询问休眠：错误：mappedBy 引用未知的目标实体属性

Posted 2023-04-14

【中文标题】询问休眠：错误：mappedBy 引用未知的目标实体属性

【英文标题】：ASK HIBERNATE: ERROR: mappedBy reference an unknown target entity property

【发布时间】：2014-12-26 22:37:02

【问题描述】：

这是我的 sql

CREATE TABLE room
(
    room_id INT,
    primary key (room_id)
) ENGINE=InnoDB;
CREATE TABLE people
(
    people_id INT,
    live_in INT,
    primary key (people_id),
    foreign key (live_in) references room(room_id)
) ENGINE=InnoDB;

这是我的第二个实体

@Entity
@Table(name="room")
public class RoomClass
    private int RoomIdMember;
    private Set<PeopleClass> Peoples = new HashSet<PeopleClass>(0);

    @Id
    @Column(name="room_id")
    public int getRoomIdMember() 
        return RoomIdMember;
    
    public void setRoomIdMember(int roomIdMember) 
        RoomIdMember = roomIdMember;
    

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "LiveInMem")
    public Set<PeopleClass> getPeoples() 
        return Peoples;
    
    public void setPeoples(Set<PeopleClass> peoples) 
        Peoples = peoples;
       


@Entity
@Table(name="people")
public class PeopleClass 
    private int PeopleIdMem;
    private RoomClass LiveInMem;

    @Id
    @Column(name="people_id")
    public int getPeopleIdMem() 
        return PeopleIdMem;
    
    public void setPeopleIdMem(int peopleIdMem) 
        PeopleIdMem = peopleIdMem;
    
    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    //@ManyToOne
    @JoinColumn(name="live_in", referencedColumnName="room_id")
    public RoomClass getLiveInMem() 
        return LiveInMem;
    
    public void setLiveInMem(RoomClass liveInMem) 
        LiveInMem = liveInMem;
    

在主函数中，当我写的时候

Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
...

Eclipse 说

mappedBy reference an unknown target entity property: quang.entity.PeopleClass.LiveInMem in quang.entity.RoomClass.peoples

为什么会出现这个错误？

【问题讨论】：

尝试使用小写的peoples作为变量名

哦，它工作，:) 非常感谢你

【参考方案1】：

尝试将Peoples 和所有其他类变量设为小写。 这是通常/标准的Java 代码约定。 我不确定，但我强烈怀疑这与您的问题有关。