Hibernate criteria of Projection

Question

I have 2 classes with a relation @OneToOne: User and Player.

User contain a player:

@Entity
@Table(name = "user")
public class User {
    @Column(name = "nickname")
    private String nickname;

    @OneToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @JoinColumn(name = "id_player")
    private Player player;

   //getters and setters...
}

I want to query user with only nickname and player, and with player I don't want all attributes, I only want 2.

This is what I have now:

    //Projections for the class User
    ProjectionList projectionList = Projections.projectionList();
    projectionList.add(Projections.property("id"), "id");
    projectionList.add(Projections.property("nickname"), "nickname");
    projectionList.add(Projections.property("player"), "player");

    Criteria criteria = session.createCriteria(User.class);
    criteria.setFirstResult(player.getPvpRank() - 5);
    criteria.setMaxResults(11);
    criteria.createAlias("player", "p");
    criteria.addOrder(Order.asc("p.pvpRank"));
    criteria.setProjection(projectionList);
    criteria.setResultTransformer(Transformers.aliasToBean(User.class));

I am getting only nickname, id and the player, but how can I set projections to the player to only get player.level and not all the attributes?

Check the detailed solution here: http://stackoverflow.com/a/29756903/4560215 — madhu pathy, May 07 '15 at 12:45

score 0 · Answer 1 · answered May 07 '15 at 09:24

0

Its think it is exactly as you suggest:

projectionList.add(Projections.property("player.level"), "player.level");

answered May 07 '15 at 09:24

KernelKoder

746
5
15

Im getting: `could not resolve property: player.level of: model.User` – Raxkin May 07 '15 at 10:18

score 0 · Answer 2 · answered May 07 '15 at 11:59

First create alias for the JoinColumn table Player in User & then refer it in your projectionList.

Criteria criteria = session.createCriteria(User.class);
criteria.createAlias("player", "p");
projectionList.add(Projections.property("p.level"), "player");
...
criteria.setProjection(projectionList);
criteria.setResultTransformer(Transformers.aliasToBean(User.class));

I hope this helps you.

Hibernate criteria of Projection

2 Answers2