Question

I have a question about hibernate.

I want to save a small graph of detached objects :

session.save(new City(1));

Peron p = new Person(new City(1), new Street(2));
session.save(p);

Hibernate told me that city is transient but I do :

session.refresh(city);
session.refresh(street);
session.update(p);

Any Idea?

Answer 1

Either do something like this:

City city = new City(1);
session.save(city);

Street street = new Street(2);
session.save(street);

Peron p = new Person(city, street);
session.save(p);

session.flush();

Or setup cascading to cascade the save operation. For example, with annotations:

@Entity
public class Person {
    @Id @GeneratedValue
    private Long id;

    @ManyToOne(cascade = CascadeType.PERSIST) // or ALL to cascade all operations
    private City city;

    // ...
}

And then the code becomes:

City city = new City(1);
Street street = new Street(2);
Person p = new Person(city, street);
session.save(p);
session.flush();

References

• JPA 1.0 specification
  • Section 3.2.1 “Persisting an Entity Instance”
  • Section 9.1.22 “ManyToOne Annotation”
• Hibernate Core Reference Guide
  • 10.11. Transitive persistence
• Hibernate Annotations Reference Guide
  • 2.4.7. Cascade (extensions of the JPA specification)