休眠 - 双向@OneToOne [英] Hibernate - bidirectional @OneToOne

问题描述

  public class User {$ b $}我有两个类：User和UserPicture，它们具有1：1的关系。 b @Id 
 @GeneratedValue（strategy = GenerationType.AUTO）
 @Column（name =id，nullable = false，unique = true）
 private int id; 
 
私人字符串名字; 
 
私人字符串姓氏; 
 $ b $ @ @OneToOne 
 @JoinColumn（name =picture）//数据库中名为picture的字段
 private UserPicture userPicture; 
 
 
 
 
 
 public class UserPicture {
 
 @Id 
 @GeneratedValue（strategy = GenerationType.AUTO）
 @Column（name =id，nullable = false，unique = true）
 private int id; 
 
私人Blob图片; 
 
 @OneToOne 
 @JoinColumn（name =user）
用户用户; 
  

User'User'中的'user'将会被加载，但user'userPicture'不会被加载 - 我做错了什么？

编辑
必须添加，我只是创建一个UserPicture并插入它们（与现有的userId） - 也许我需要级联'User'in UserPicture？

解决方案

您必须映射您的类。

  public class User {
 ... 
 @OneToOne（mappedBy =user）
 private UserPicture userPicture; 
 ... 
} 
 
 public class UserPicture {
 ... 
 @OneToOne 
 @JoinColumn（name =user） 
私人用户用户; 
 ... 
} 
  

I have 2 classes: User and UserPicture which have a 1:1 relationship.

public class User {
     @Id
     @GeneratedValue(strategy=GenerationType.AUTO)
     @Column(name="id", nullable = false, unique = true)
 private int id;

     private String firstname;

     private String lastname;

     @OneToOne
     @JoinColumn(name = "picture") //field named "picture" in the database
     private UserPicture userPicture;

     ..
}


public class UserPicture {

     @Id
     @GeneratedValue(strategy=GenerationType.AUTO)
     @Column(name="id", nullable = false, unique = true)
     private int id;

     private Blob image;

     @OneToOne
     @JoinColumn(name = "user")
     User user;

'user' in UserPicture will be loaded but 'userPicture' in User not - what did Im wrong?

EDIT Have to add that Im just create a UserPicture and insert them (with existing userId) - maybe I need to cascade 'user' in UserPicture?

解决方案

You have to map your classes.

public class User {
    ...
    @OneToOne (mappedBy="user")
    private UserPicture userPicture;
    ...
}

public class UserPicture {
    ...
    @OneToOne
    @JoinColumn (name="user")
    private User user;
    ...
}

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