一对多单向休眠映射不保存子表 [英] one to many unidirectional hibernate mapping doesn't save the child table

问题描述

我有两个表，分别称为 Person 和 Address.我使用注释将这些表映射到一对多.

I have two tables called Person and Address. These tables I mapped one to many with hibernate using annotation.

然后在我的父实体 Person 中创建一个 Set

来保存子类.之后，我创建了一组地址并设置为 Person 实体并设置 Person 自己的值.

Then in my parent entity Person I create a Set<Address> to hold the child class. After that I create a set of address and set to Person entity and also set Person's own values.

我的问题是，当我保存时，父实体子实体没有保存在数据库中.

My problem is that when I am save the parent entity child does not save in DB.

这是我的代码:

Person.java

@Entity
@Table(name="PERSON")
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="personId")
    private int id;
    @Column(name="personName")
    private String name;
    @OneToMany(cascade =CascadeType.ALL,fetch = FetchType.EAGER)
    @JoinColumn(name="personId") 
    private Set <Address> addresses;

Address.java

@Entity
@Table(name = "ADDRESS")
public class Address {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "addressId")
    private int id;
    @Column(name = "address")
    private String address;
    @Column(name="personId") 
    private int personid;

我的 DAO:

   public Person addNewPerson() {
    Person per = new Person();
    per.setName("aaaa person");
    Set<Address> addressSet = new HashSet<Address>();
    for(int i = 0; i<=3;i++){
        Address ad = new Address();
        ad.setAddress("aaa "+i);
        addressSet.add(ad);

    }
     per.setAddresses(addressSet);
     getHibernateTemplate().save(per );
    }

这里的人正在我的表中添加但地址未保存.为什么?

Here person is adding in my table but address is not saved. Why?

双向是可能的，但单向是我的问题

bidirectional it is possible, but in unidirectional is my problem

推荐答案

personId 列被映射两次:一次是保存地址的人的外键，使用 JoinColumn 注释，并作为地址中的常规 int 列一次.

The personId column is mapped twice : once to hold the foreign key to the person of the address, using the JoinColumn annotation, and once as a regular int column in the address.

从地址中删除 personId 字段.如果您想从地址访问人员 ID，则将该关联映射为双向 OneToMany/ManyToOne 关联.

Remove the personId field from the address. If you want to have the access to the person ID from the address, then map the association as a bidirectional OneToMany/ManyToOne association.

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