Retrieve only the superclass from a class hierarchy
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Published on 2012-11-01T22:37:31Z
Indexed on
2012/11/05
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I have an scenario as the following:
@Entity
@Table(name = "ANIMAL")
@Inheritance(strategy = InheritanceType.JOINED)
public class Animal implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "S_ANIMAL")
@SequenceGenerator(name = "S_ANIMAL", sequenceName = "S_ANIMAL", allocationSize = 1)
public int getNumero() {
return numero;
}
public void setNumero(int numero) {
this.numero = numero;
}
.
.
.
}
and as the subclass:
@Entity
@Table(name = "DOG")
public class Dog extends Animal {
private static final long serialVersionUID = -7341592543130659641L;
.
.
.
}
I have a JPA Select statement like this:
SELECT a FROM Animal a;
I'm using Hibernate 3.3.1
As I can see the framework retrieves instances of Animal
and also of Dog
using a left outer join.
Is there a way to Select only the "part" Animal
? I mean, the previous Select
will get all the Animal
s, those that are only Animal
s but not Dog
s and those that are Dog
s.
I want them all, but in the case of Dog
s I want to only retrieve the "Animal part" of them.
I found the @org.hibernate.annotations.Entity(polymorphism = PolymorphismType.EXPLICIT)
but as I could see this only works if Animal isn't an @Entity
.
Thanks a lot.
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