Hello,
I have an object whose fields belong to more than one table. I would like to know if and how to map it in the hbm.xml file. Based on a quick pass at the reference doc I'm not able to get any details on it. Could someone lead me with links or code snippets etc I would appreciate your help.

If I'm not clear in my question please let me know.

note: I do not have the luxury of changing the existing db table struture.

Thanks
Pradeep

Hibernate version:
3.1
Name and version of the database you are using:
oracle 9i

perhaps you can model something with joined-subclass, where your class will be the subclass:
http://www.hibernate.org/hib_docs/v3/re ... edsubclass
or you could define one-to-one relationships and have properties from another table mapped to a component of your class

I have this requirement addressed using

section 8.3.3. one to one in reference doc
A unidirectional one-to-one association on a join table.

also visited http://forum.hibernate.org/viewtopic.php?t=943843&

Thanks
Pradeep

Or use the join element of class. It has the advantage that the second table doesn't have to be modelled as a nested object in java.



Note that join must come after your other properties, maps, many-to-ones etc in your first class.

Domain model:
Claim object contains loan object

public class Claim {
private Long workorderId;
private Date responseDate;
private String submittedBy;
private Date claimDate;
private Loan loan;
}

public class Loan {
private String loanNumber;
private String state;
private Date customerChangeDate;
}


I have tables with the below given structure:
table name: workorder
workorder_seq (pk)
responseDate
loanNumber
state
submittedBy

table name: claim
workorder_seq (pk)
claimDate
customerChangeDate

workorder and claim table have one-to-one relationship

I would like to know how to create a mapping file with the above given
domain objects and table structure.

I read about the component and join elements for the mapping file. But I'm unable to figure out how to support the above structure in a mapping file.

Note: requirement is I cannot change either the domain model or the table structure.

Database used is oracle 9i
hibernate version used is 3.1

Thanks
Pradeep

I can't find an solution to your very strange problem. You could map Claim to workorder and join in customerChangeDate, then add a one-to-one to Loan, which maps to claim and joins in claimDate, but I don't know if that would work. It's a pity <component> doesn't allow a <join> element, but this problem has got to be very rare, no point in solving it if the solution is only going to be used once.

My solution would be to create a single class ClaimLoanImpl, which implements the Claim and Loan interfaces. Claim.getLoan() returns (Loan) this. Use hibernate to map both tables to ClaimLoanImpl (using join). Undoubtedly there's a better solution; you can't use even this solution if your not-changing-domain-model rule disallows you from changing Claim and Loan to interfaces.