Re: OpenJPA - two-sided relation between objects Issue

[Craig L Russell]

Hi Madhu,




Craig

On Aug 13, 2008, at 10:28 AM, Madhu Kalaimalai wrote:

I assume that with the suggested changes to your persistent classes, the only issue is with the setAddressId method? Would it be possible to implement this as a no-op?

Hi Craig

Thanks for the reply.


Address address =  new Address();
address.setAddrTypeId(67548);
address.setCountry("USA");
em.persist(address);
em.flush();
Phone newPhone = new Phone();
newPhone.setTelphoneNum("99999");
newPhone.setIntlPhoneInd("Y");
newPhone.setPhoneTypeId(65093);
newPhone.setPrimaryNumInd("Y");
newPhone.setAddressId(address.getAddrId());
em.persist(newPhone);

The existing code is huge, we don't want to refactor.


Address object to map

good.


the setAddresId impl to work for the new mapping ?

If needed i can send the sample code.

Rgds
Madhu




Craig L Russell wrote:

The way the old code works is first persist the address and then get the id of the address, create the phone object and set the adress id as the fk ie setAddrId which is mapped to the ADDR_FK_ID of the PHONE table as below In the new case, we are not doing any mapping of the addressId and using the to addressId. Your point of getAddressId getting the reference of Address is How do we make the above code work with the new mapping ie how do we make

I know I'm jumping into this issue late, but here goes:

In order for OpenJPA to manage the relationships, you need to define
the association between the classes by using the mappedBy="address"
notation on Address.phones. This way, OpenJPA knows about the
bidirectionality of the relationship and knows to populate both sides
to be consistent.

In order to return the addressId, you need to use the getId method of
address and not persist the addressId separate from the relationship,
or have a separate addressId field.

So, I'd think this would work:

class Phone {
public Long getAddressId()
{
return this.address.getId();
}

Basically, if you eagerly fetch Address, the Id will be available.

Then, as Pinaki said earlier, the only thing you might need to do to
make the getAddressId valid is to flush the relationship. Then the

transaction is either flushed or committed.

Craig

On Aug 12, 2008, at 3:35 PM, Madhu Kalaimalai wrote:

code that depends on the relationship will still work after the create

Hi Pinaki

The id is generated through the oracle sequence, so the id is not
know till
the SQLs are generated.

The problem being having the addrId and Address having mapped to the
one
column ADDR_FK_ID of the Phone table as we wanted the old way of
using the
AddrId and new way of Address to work.

When i do the one direction from Address to Phone, it says we are
trying to
set two different values to same object. For this case for the
AddrId column
mapping it sets null and for the Address mapping it sets the Address
primary
key.

When I do the bidirectional mapping, the insert statements to Phone
has
addrId columns twice one for the AddrId and other for Address. It
says the
duplicate column in the insert statement.

I am looking at the possibility of POJOs supporting the old and new
way of
persistence.

Hope you got what i am trying to explain.

Rgds
Madhu



Pinaki Poddar wrote:

Hi,
The mapping you described originally in this post should work as
well.
Of course, the application must set the values of ADDR_FK_ID from
both
sides consistently.
For example, if there is one Address instance A1 with id 12345 and
A1.phones is a Set that contains two Phone instances P1 and P2.
Then the
application must ensure that for both P1 and P2 addressId field is
set to
12345 before commit. The problem will be complicated only if
Address has
auto-generated identity.

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Craig L Russell

Architect, Sun Java Enterprise System http://java.sun.com/products/ jdo

408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!

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View this message in context: 
http://n2.nabble.com/OpenJPA---two-sided-relation-between-objects-Issue-tp687050p722443.html
Sent from the OpenJPA Users mailing list archive at Nabble.com.

Craig L Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!

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