@OneToMany relationship does not save the primary key of the parent in the children tables Code Answer

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: 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;
       }
   }
   

2. 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;
       }
   }
   

3. 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;
       }
   }
   

A code to save the person:

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);

Answer

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);