建立几个一对多的关系

Question

它实现了如下所示的模型：

我实现了三类模型：

@Entity
public class Home implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @OneToMany(mappedBy = "home")
    private Set<UserHome> userHomes;
}
@Entity
public class UserHome implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @ManyToOne
    @JoinColumn(name = "home_id")
    private Home home;

    @OneToMany(mappedBy = "userhome")
    private Set<Key> keys;
}
@Entity
public class Key implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @ManyToOne
    @JoinColumn(name = "userhome_id")
    private UserHome userHome;
}

当您尝试编译时会出现错误：

  

调用init方法失败;嵌套异常是org.hibernate.AnnotationException：mappedBy引用一个未知的目标实体属性：com.example.homeUser.UserHome.keys中的com.example.homeUser.Key.userhome

我不知道我的代码有什么问题？

Answer 1

您的代码中存在拼写错误，$mimetype = mime_content_type($path); switch ($mimetype) { case "video/mp4": // what is currently your case "1" break; case "image/jpeg": case "image/pjpeg": case "image/png": case "image/gif": // what is currently your case "2" break; default: return array( 0, "file format is unknown" ); } 中的小写h：

userhome

应为（大写H）：

@OneToMany(mappedBy = "userhome")
private Set<Key> keys;

您在@OneToMany(mappedBy = "userHome") private Set<Key> keys; 这样的字段中引用的字段/属性应该具有JavaBean中字段的确切名称和大小写。