[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-4233) cant bind a child using mappedby relating to a parent attribute(polymorphism)

[Emmanuel Bernard (JIRA)]

    [ http://opensource.atlassian.com/projects/hibernate/browse/HHH-4233?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=43147#comment-43147 ] 

Emmanuel Bernard commented on HHH-4233:
---------------------------------------

Again, this model is not sound and claiming we can support it would simply be fooling you. 

It's not a bidirectional relationship it's some Frankenstein tri-directional one. 
I can write code that associates a Dog to a Person and get it loaded as a Cat. Java does not support duck (or dog or cat) typing ;)
Try and represent your model with the bidirectional association (and not two different associations) into UML and you will see you cannot. 

> cant bind a child using mappedby relating to a parent attribute(polymorphism)
> -----------------------------------------------------------------------------
>
>                 Key: HHH-4233
>                 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-4233
>             Project: Hibernate Core
>          Issue Type: Bug
>          Components: annotations
>         Environment: osx 10.4, java 1.5
>            Reporter: Nino Martinez
>         Attachments: JPA101.zip
>
>
> This is pseudo class hieracy
> @Entity
> @Inheritance(strategy = InheritanceType.JOINED)
> Mammal
> {
> @ManyToOne
> Person owner;
> }
> @Entity
> Cat extends Mammal
> Person{
> @Cascade(org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
> 	@OneToMany(cascade = { CascadeType.PERSIST, CascadeType.MERGE,
> 			CascadeType.REMOVE }, mappedBy = "owner")
> 	private List<Cat> cats = new ArrayList<Cat>();
> }
> it gives the error mission property:
>  javax.persistence.PersistenceException: org.hibernate.AnnotationException: mappedBy reference an unknown target entity property:
> Cat.owner in Person.cats
> This is the related thread on hibernate forum:
> http://forum.hibernate.org/viewtopic.php?p=2380570#2380570
> I can confirm that the same example does work when using OpenJPA as a provider. Please see attached project for reference.
> Please do not hesitate me if you have questions.

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