Why does Hibernate execute multiple SELECT queries instead of one when using @Fetch(FetchMode.JOIN)

Question

I\'ve got the following query which I expect to run in a single select request:

@NamedQuery(name=Game.GET_GAME_BY_ID1,
                query = \"SELECT g FROM Ga         


        

Answer 1

The secondary queries come from:

@ManyToOne(fetch=FetchType.EAGER)
@Fetch(FetchMode.JOIN)
@JoinColumn(name="team_id2")
public Team getTeam2() {
    return team2;
}

So, you need to:

1. Make all associations LAZY. By default, all @ManyToOne and @OneToOne associations are EAGER, so it's better to have them LAZY and only override the fetch plan on a query basis.

2. Remove the @Fetch(FetchMode.JOIN), which is essentially an EAGER fetch directive. In your case, not just the team2 property is fetched, but its players and skills as well.