hibernate学习笔记6

最新推荐文章于 2022-09-05 00:29:31 发布

原创最新推荐文章于 2022-09-05 00:29:31 发布 · 303 阅读

0 ·

CC 4.0 BY-SA版权

ssh 专栏收录该内容

65 篇文章

订阅专栏

本文详细介绍了Hibernate中MappedBy属性的使用方法及其意义，包括其适用范围、定义位置及与JoinColumn的区别，并通过Husband-Wife关系模型进行了具体演示。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

@Entity
public class Husband {
   private int id;
   private String name;
   private Wife wife;
   @Id
   @GeneratedValue
   public int getId() {
       return id;
   }

   public String getName() {
       return name;
   }
   @OneToOne
   @JoinColumn(name="wifeId")   //外键名称
   public Wife getWife() {
       return wife;
   }
   public void setId(int id) {
       this.id = id;
   }
   public void setName(String name) {
       this.name = name;
   }
   public void setWife(Wife wife) {
       this.wife = wife;
   }

}

@Entity
public class Wife {
   private int id;
   private String name;
   private Husband husband;

Hibernate中的MappedBy：

1）只有OneToOne,OneToMany,ManyToMany上才有mappedBy属性，ManyToOne不存在该属性；

2) MappedBy标签一定定义在the owned side(被拥有方)，他指向the owning side(拥有方)；

3) MappedBy的含义，应理解为，拥有放能够自动维护跟被拥有方的关系。

4）MappedBy跟JoinColumn/JoinTable总是处于互斥的一方。

   @OneToOne(mappedBy="wife")
   public Husband getHusband() {
       return husband;
   }
   public void setHusband(Husband husband) {
       this.husband = husband;
   }
   @Id
   @GeneratedValue
   public int getId() {
       return id;
   }
   public void setId(int id) {
       this.id = id;
   }
   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }

}

Wife w=new Wife();
        w.setName("w");

        Husband h=new Husband();
        h.setName("h");
        h.setWife(w);

        Session session = sessionFactory.getCurrentSession();
        session.beginTransaction();
        session.save(w);
        session.save(h);

        session.getTransaction().commit();