Hi, I'm mapping my old (and poorly structured) database in hibernate. I have one table called Account, another called Fund, and a third called Balance.

Balance says how much money an account has in a given fund. So Account has a one-to-many relationship to Balance. Fund also has a one-to-many relationship to Balance.

So here's where it gets messy. Balance doesn't have a proper primary key. It has a foreign key to each of the two tables it is connected to. The two foriegn keys form a composite key on the table.

Oh, and the name of the foreign key to Fund is not the same name as the primary key on fund, but it holds the same data.

What is the proper way to write the mapping file?

Thank you in advance.

You could use a composite key with a key-many-to-one mapping.


Farzad-

Thank you farzad. This appears to be what I need to do.

I do have one additional problem though. One of the columns has a different name on the two tables. So the table Balance has a column named fund and it references the column named code on the fund table. Does anyone know how to handle that?

I am not sure if I understand the problem correctly (means I didn't read your post carefully) but I have a feeling you are looking for property-ref, by which you can specify this relationship is not based on primary keys (and similar) but the specified property-ref makes the relationship. Tell me if this is what you need.



Farzad-

In sql the relationship between the tables would be stated as "select * from fund f, balance b where f.code=b.fund" I'm not sure who to express this relationship in Hibernate. Most things I read assume that the columns have the same name on both tables.

How does your mapping look like right now? I'd assume code is a primary key in fund then you would have something like:






Farzad-

Thanks I guess it wasn't as complicated as I thought it was.