Hi

Sorry if this is really easily answered but I've got my head in a spin....

I've two classes.

- Person
- Address

Person has a ManyToOne relation with Address.

Is it possible to have Person pointing to one database and Address to a complete different one, in H3?

And if so... is it possible too for both classes to be in differents JAR files? each one with its own persistence.xml file?

Please I really need help with this...

This is not exactly what I'm looking for.

Let's say I've an entity Person.

[code]Person
-------
private Integer id
private String name

It's not written by me and is built in common-entities.jar.

That file has it's own persistence.xml, pointing to an oracle database.



Now I'm building my own project, wich references "common-entities.jar" and I have the entity Employee.
This project points to a MySQL database.

[code]

public class Employee {

private Integer id
private String jobDescription

@OneToMany(cascade={CascadeType.All}, fetch=FetchType.EAGER)
private Person person

[/code]

So a write a form to update Employee and enable it to change the "name" property of Person.

What I want to know is if Hibernate can tranparently treat this relation even if both entities point to diferent database.

Hibernate cannot do that. It would have to dig deeply into each database's transaction engine to get a two-phase commit working, and that's simply outside of Hibernate's scope.

However, I think there are solutions outside Hibernate itself.
One way would be to check if your database offers a way to include tables from external databases (possibly even from a different vendor) in their catalog. For example, Oracle has a "database link" feature that does that.
I dimly remember that I stumbled upon some middleware that does similar things when I was researching connection pooling modules. It was one of those four-letter acronyms that I keep forgetting, so maybe somebody else can pick up.

Ok. Thanx!