I have the following @OneToOne
relation:
@Entity
@Table(name="USER")
public class User implements Serializable{
private Basket basket;
@OneToOne(cascade = CascadeType.ALL,orphanRemoval=true,mappedBy="user", fetch=FetchType.LAZY )
public Basket getBasket() {
return basket;
}
public void setBasket(Basket basket) {
this.basket = basket;
}
//all other proerties are ommited and none relevant.
}
Now the basket class:
@Entity
@Table(name="BASKET")
public class Basket implements Serializable {
private User user;
@OneToOne(fetch=FetchType.LAZY)
public User getUser() {
return user;
}
//all other proerties are ommited and none relevant.
}
Now I'm trying to fetch User object using HQL in object which has Spring Transaction manager using AOP:
public User getUser(String param1,String param2) {
Session session = this.sessionfactory.getCurrentSession();
String queryString = "from objects.User user where user.param1=:param1 and user.param2=:param2";
Query query = session.createQuery(queryString);
query.setString("param1", param1);
query.setString("param2", param2);
User user = (User) query.uniqueResult();
return user;
}
but I see that Basket is also fetched although it's Lazy:
Hibernate: select user0......
Hibernate: select basket0.....
Why?
Because a one-to-one normally represents highly cohesive objects and is fetched using a join by default, so there's little reason not to fetch both user and basket. I'm not sure why you're seeing two separate selects. I believe that should only happen if you tell it specifically to fetch using a select instead of a join. This article does a good job of analyzing a one-to-one relationship. It might help you out.
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