CODEWITHSUNDEEP
javahibernate
Igor
Igor

Reputation: 658

Hot get List of objects with Hibernate, when Entity mapped as Many To One

I have a class User, that contains List of Contacts User class:

@Entity
@Table(name = "profile")
public class User implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

    @Column(unique = true)
    private String login;

    @OneToMany(mappedBy = "owner", cascade = CascadeType.ALL)
    private List<Contact> contacts;
    ...
    ...
}

Contact class:

@Entity
@Table
public class Contact implements Serializable {
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private int id;

        @ManyToOne
        @JoinColumn(name = "user_profile_id")
        private User owner;
        ...
        ...
    }

how may i get List of Contacts by User.id field?

Upvotes: 0

Views: 4390

Answers (2)

v.ladynev
v.ladynev

Reputation: 19956

Contact has a foreign key column associated to User so you don't need to use join 

from Contact where owner.id = :userId

Please, don't use primitive types like int id, use Integer id instead.

Upvotes: 0

Guillaume
Guillaume

Reputation: 494

Not sure I got what you want...

Simply look for the User by Id, and you will get his/her contacts. However, the collection will be lazy loaded, and the list will be really loaded when you will call getContacts() or Hibernate.initialize(user.getContacts()). Change FetchMode as EAGER in the @OneToMany in case you don't want lazy loading...

For e.g., using HQL Query :

String hql = "from User where id = :userid";
Query query = session.createQuery(hql);
query.setInteger("userid", myUserIdIWantContacts);
User user = (User) query.uniqueResult();

or Criteria :

Criteria cr = session.createCriteria(User.class);
cr.add(Restrictions.eq("id", myUserIdIWantContacts));
User user = (User) cr.uniqueResult();

Upvotes: 1

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