相关疑难解决方法(0)

这与"没有单独的连接表的Hibernate @OneToMany"类似,我需要一个没有连接表的@OneToMany关系.但是,我还想不定义反比关系.删除反转似乎会导致自动生成连接表...是否有解决方法？

我试图在两个JPA实体之间生成单向一对多映射.在我的ChatRoom课堂上,我有一个Vector<User>表示Users中的s 的类型对象ChatRoom.我正在尝试基于userId(在User类中)创建一对多映射.这是我的示例代码:

@Entity
public class ChatRoom {
    @Id
    @GeneratedValue
    private int chatRoomID;

    @OneToMany(mappedBy="userID")
    private Vector<User> users;

    // A no-argument constructor is required for EclipseLink to instantiate the persistence object properly.
    public ChatRoom() {}

    // Getter/Setter section
}

这是User类:

@Entity
public class User {
    @Id
    @GeneratedValue
    private int userID;

    private String username;

    // Getter/Setter section
}

当我尝试在Eclipse中从这些实体生成表时,我收到以下错误:

Internal Exception: javax.persistence.PersistenceException: Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.0.2.v20100323-r6872): org.eclipse.persistence.exceptions.EntityManagerSetupException
Exception …