Everyone,

I need your help understanding how to use Hibernate to combine different objects/tables into a class.

Assume the following are tables and objects.

User
- id (primary key)
- name

UserProfile
- userId (foreign key to User.id)
- ssn

UserBalance
- userId (foreign key to User.id)
- money

This example is very simple, and I realize the three things could/should be combined into one table. But please bear with me.

Assume I want a fourth object used in presenting results from a user search. It holds the following:

UserSearchResult
- User.id
- User.name
- UserProfile.ssn
- UserBalance.money

This fourth object does not map directly to a table. All it does is encapsulate information from a query.

How do I represent this in Hibernate? I

I think you may be interpreting the term many-to-one incorrectly. In object terminology, this always refers to multiplicity. So it describes an association relationship between to objects, where one side of the association has many instances of a given type, and the other side has one instance of another type:



This terms does not describe turning multiple tables into a single class, such as you desire to create in your example of user parts. To do this I think you may do best with joined subclasses. I think you will need one subclass per table type. This could be your hierarchy:



But in my opinion, you may do better with the following class composition:



I suggest this because profile information has little to do with a finanical account, really. But since your example may simply be abstract, the first hierarchy would give you what you are trying to do.

Just a suggestion. I hope I have not misunderstood your question.

Vaughn

Nope, I think you understood perfectly.

I think the full answer is, "Hibernate can't do *exactly* what I want it to.

No problems. I'll just write a SQL query, and load the object the old fashioned way.

Thank you very much for the response.

Lukas

I guess the following Hibernate 3 feature could do the job:



But I don't know if this is already done and how to use it :-(.

HTH
Ernst