@OneToMany关系不会将父级的主键保存在子级表中 [英] @OneToMany relationship does not save the primary key of the parent in the children tables

问题描述

让我们有三个JPA实体.一个Person和两个一对多关系.当我尝试保存Person AD_P_ID和AC_P_ID外键时，它们始终为null. 这些字段的期望值是个人ID.我在做什么错了?

Let there be three JPA Entities. A Person and two one-to-many relations to it. When I'm trying to save the Person AD_P_ID and AC_P_ID foreign keys are always null. The expected value for these fields is the person Id. What am I doing wrong?

1. Person.java:它包含与Account和Address实体类的一对多关系:

1. Person.java: This contains one to Many relationships with Account and Address Entity classes:

@Entity
@Table(name = "A2C_PERSON")
class Person implements Serializable {

    private long id;

    private List<Account> acs;

    private List<Address> ads;

    @OneToMany(cascade=CascadeType.ALL, mappedBy = "person")
    public List<Account> getAccount() {
        return this.acs;
    }

    @OneToMany(cascade=CascadeType.ALL, mappedBy = "person")
    public List<Address> getAddress() {
        return this.ads;
    }
}

Account.java

Account.java

@Entity
@Table(name = "A2C_ACCOUNT")
public class Account implements Serializable {

    private long id;

    private Person person;

    @ManyToOne(cascade=CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinColumn(name = "AC_P_ID")
    public Person getPerson() {
        return this.person;
    }
}

Address.java

Address.java

@Entity
@Table(name = "A2C_ADDRESS")
public class Address implements Serializable {

    private long id;

    private Person person;

    @ManyToOne(cascade=CascadeType.ALL,fetch = FetchType.LAZY)
    @JoinColumn(name = "AD_P_ID")
    public Person getPerson() {
        return this.person;
    }
}

用于保存人员的代码:

Person p = new Person();

Account ac1 = new Account();
Account ac2 = new Account();
List<Account> acList = new ArrayList<>();
acList.add(ac1);
acList.add(ac2)

Address ad1 = new Adddress();
Address ad2 = new Adddress();
List<Address> adList = new ArrayList<>();
acList.add(ad1);
acList.add(ad2)

p.setAcs(acList);
p.setAds(adList);

personRepo.save(p);

推荐答案

对于每个Address和Account实体，您需要设置Person实体. 为了使休眠状态将ID保存在子级中，这是强制性的:

For each Address and Account entity you need to set the Person entity. This is mandatory in order for hibernate to save the ids in children:

Person p = new Person();

Account ac1 = new Account();
ac1.setPerson(p);  
List<Account> acList = new ArrayList<>();
acList.add(ac1);

Address ad1 = new Adddress();
ad1.setPerson(p);
List<Address> adList = new ArrayList<>();
acList.add(ad1);

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