Question

I have 2 models with a @OneToOne relationship. Let’s say a model User and a model Player. Each user is a player and each playeris a user.

Here is the code of these 2 models :

@Entity
public class User extends Model {

    @Required
    public String name;

    @OneToOne(fetch = FetchType.EAGER)
    public Player player;
}

@Entity
public class Player extends Model {

    @Required
    public String nickname;

    @Required
    public Gender gender;
}

I will always access a Player from a User and I want that when I load a User, his Player is also loaded (that’s why I used fetch = FetchType.EAGER).

So I expect (for optimization purposes) that when I load a User, the query is a JOIN query that also loads the Player.
Something like :

select u, p from User u join u.player p where u.player_id = p.id

But when I look at the queries count and the queries debug output I can see that 2 queries are performed.
Something like:

select u from User u
select p from Player p where p.id = ?

But this is not optimized, how can I make JPA perform a join request to get my User and its Player ?

Tank you for your help!

EDIT : I’m using Play framework 1.2.5

Answer 1

In the User class, as you noticed in your comment that the player can be null

public static void findByIdWithPlayer(Long id) {
    find("select distinct user from User user left join fetch user.player where user.id=?", id).first();
}