Hello, I am migrating an application from Toplink to Hibernate.

Toplink has a weird way to map 2 tables and become it in one singe object.

Example:

Table fields....

Table A
---------
A.ACODE >
> composite-id
A.BCODE >

Table B
---------
B.CODE > FK with A.ACODE
B.TEXT

I whould like to have one class with the atributes

private Integer Aacode;
private Integer Abcode;
private String Btext;

Is there any way to do it?

I saw something different at hibernate documentation...telling about composite identifiers but it is not what I want to do.

So could someone try to explain me how to do it?

I think it is possible to do the same with View in database

We don't support mapping one object to multiple tables yet (it is on the roadmap for 2.2). You could work around probably by mapping two objects and using delegation.

That's ok, I think I can create a join object for now and simply do the mappings independent.

I am having another other problem and I whould like to ask you because it has been a headache to me.

I have one table with composite-id that is described above.

TABLE A
---------
A.CODE > PK (2 elements)
A.TEXT >

and other table with composide-id that is described above.

TABLE B
----------
B.CODE >
B.TEXT1 >> PK (3 elements)
B.TEXT2 >

I am trying to map a Set of one-to-many from A.CODE to B.CODE but I get an error here as described above...

Foreign key must have same number of columns as referenced primary key

Therefore I am using XDoclet to generate the mappings...

It's so complicated to understand this...please help me.

It seem like that would be a many-to-many relationship. Is code the primary key of another table? If it is I would map to these relationships via the code entity. It that is not the case, my guess is that a Map with many-to-many may return what you want. You would end up with something like a map element containing a key, index/column(s), and a many-to-many element.

It is not a many-to-many, sorry for my mistake to do not explain this, I was kind of desperate. on TABLE A I have a one to many to TABLE B.

Something like that

Seems that there is some bright light in the end of the tunnel, whould be very nice if you please could tell me how whould I make this happen with xdoclet?

Like Emannuel said I should map as this....

<class name="B">
<composite-id ...>
<key-many-to-one name="a" class="A">
<column name="code" .../>
<column name="text1" .../>
</key-many-to-one>
<key-property name="text2" .../>
</composite-id>...

But the key-many-to-one is composed only with A.CODE not with A.TEXT

For the mapping on class A the join should be A.CODE to B.CODE one to many.

And for the class B the join should be B.CODE many to one to A.CODE but it does not work.

Please I need some help. How to do it with XDOCLET either.

Like emmanuel said is not possible to map the pk of table B as the table A because the table A also has a composite ID.

I am really frustrated to do not be possible to do this....

I don't get your problem. You said

So CODE and TEXT is the A composite id. That's why I proposed this mapping.

Mapping A with B using only a part of the id is incosistent as per the many-to-one definition. This is a many-to-many. But I've never try to map a many-to-many using the entity table as link table

Hi Emmanuel, you were right....

The mistake was in the relation on toplink implementation and I now know it is a many to many relation.

Sorry for the misunderstandings.

Hi there, as I got the many-to-many problem now I had tried to do so.

But I am getting another weird error.....

When mapping many-to-many A.CODE to B.CODE and B.CODE to A.CODE I get this error message.....

Repeated column in mapping for collection: com.example.beans.B.a column: CODE

Hard to tell without your mappings. You must not map the same column twice (for example once in a property and once in a relationship). If you do, you must set one to insert=false update=false.

Thanks for the quick reply.

I think i can't set the insert=false, update=false in the Set and either in the composite-id.

Am I right?