Hibernate: Used mappedBy on class that extends another class annotated as JoinedSubclass?

Question

The following doesn't work:

@Entity
class Owner {

  @OneToMany(mappedBy="owner", cascade = {CascadeType.ALL})
  protected Set<B> getBSet() {
    ..
  }

}

@Entity
@Inheritance(strategy=InheritanceType.JOINED)
class A {
   @ManyToOne
   public Owner getOwner() {
     ...
   }
}

@Entity
class B extends A {

}

It causes an exception as such: org.hibernate.AnnotationException: mappedBy reference an unknown target entity property: B.user in Owner.

I am trying to avoid copying the "owner" property into class B (which will consequently "denormalize" and copy the owner key into both tables generated for entity A and B). Also, I would really like to have A and B in a separate table and not have to use a discriminator by using SingleTable inheritance.

Also, I can't figure out how to do something similar by using @OneToOne between A and B (and not having B extend A).

Answer 1

It's a Hibernate oddity, but it's deliberate. I have a blog post up with background information, links and a workaround for the JOINED solution.

Answer 2

Try adding targetEntity = Transaction.class. This worked for me when I was using SINGLE_TABLE inheritance. I didn't try it with JOIN.

@Entity
class Owner {

  @OneToMany(mappedBy="owner", cascade = {CascadeType.ALL}, targetEntity = Transaction.class)
  @Where(clause = "tableType='I'")
  protected Set<B> getBSet() {
    ..
  }

}