I am trying to persist a one-to-many and a many-to-one relation using Hibernate 4.1.1 but the foreign key is always NULL.
There are two entities: Account and Client. A Client could have multiple Accounts while an Account has exactly one Client.
Here are the classes (only what matters):
Account.java
@Entity
@Table(name = "account")
public class Account implements Serializable {
private Client client;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "id")
public long getId() {
return id;
}
@ManyToOne
@JoinColumn(name = "id_client")
public Client getClient() {
return client;
}
}
Client.java
@Entity
@Table(name = "client")
public class Client implements Serializable {
private List<Account> accounts;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "id")
public long getId() {
return id;
}
@OneToMany(mappedBy = "client", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
public List<Account> getAccounts() {
return accounts;
}
}
Test.java
session.beginTransaction();
Client client = new Client();
Account account1 = new Account();
Account account2 = new Account();
a.addAccount(account1);
a.addAccount(account2);
session.save(client);
session.getTransaction().commit();
While running, Hibernate adds the foreign key to the table:
Hibernate: alter table account add index FKB9D38A2D3B988D48 (id_client), add constraint FKB9D38A2D3B988D48 foreign key (id_client) references client (id)
Both accounts have id_client column NULL.
I tried putting nullable = false at the @JoinColumn relation but that just invoked an exception.
Exception in thread "main" org.hibernate.exception.ConstraintViolationException: Column 'id_client' cannot be null
Figured it out. I forgot to add the client to the accounts.
account1.setClient(client);
account2.setClient(client);
Now it works. Thank you for the tips. ;)
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