Hello,

Our team chose to create seperate class mapping files for each Persistent class. A.hbm.xml, B.hbm.xml, C.hbm.xml, etc.

We are using Hibernate version 1.2.x.

They are then added to the Hibernate Datastore. Hibernate seems to require that the classes be added to the Datastore in a pre-defined order. Mapping exceptions occur if you add them to the datastore out of order.

If Class A depends on Class B then mapping exceptions occur if you add class A before class B.

How do you handle the case where Class A has a reference to Class B and Class B also has a reference back to Class A.

For example:

Class A has a set of Class B.
Class B has a reference to a single Class A.

We like the concept of small hbm.xml files for each class, but want to avoid duplicate class definitions and maintenance.

Is there a way to create a hbm.xml file that includes other hbm.xml files?

Is there another solution aside from creating one master hbm.xml mapping file?

Thanks in advance.

Hibernate goes a certain length to avoid requiring ordering - so can you post a small example set of hbm.xml's (2 should be enough) that show this problem ?

Class SigningApptDbBean:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-1.1.dtd">
<hibernate-mapping>
<class name="com.ditech.signingappt.db.SigningApptDbBean" table="pub.signing_appt">
<id name="loanNumber" type="string" column="loan_no" >
<generator class="assigned" />
</id>

<!-- .... stuff removed ...-->

<one-to-one name="loan" class="com.ditech.loanexceptions.db.LoanDbBean" />

</class>
</hibernate-mapping>





Class LoanDbBean:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-1.1.dtd">
<hibernate-mapping>

<class name="com.ditech.loanexceptions.db.LoanDbBean" table="pub.loans">
<id name="loanNumber" type="string" column="loan_no" >
<generator class="assigned" />
</id>

<!-- stuff removed ... -->

<set role="signingAppts">
<key column="loan_no" />
<one-to-many class="com.ditech.signingappt.db.SigningApptDbBean" />
</set>

</class>
</hibernate-mapping>

Then we add them to the datastore using static initialization code blocks in DAO objects.

In Class LoanDb ( a DAO ) :

datastore.storeClass(BorrowerDbBean.class);
datastore.storeClass(SigningApptDbBean.class);
datastore.storeClass(LoanDbBean.class);


In Class SigningApptDb:

datastore.storeClass(NotaryDbBean.class);
datastore.storeClass(VendorDbBean.class);
datastore.storeClass(BorrowerDbBean.class);
datastore.storeClass(LoanDbBean.class);
datastore.storeClass(SigningApptDbBean.class);

NOTE: there is code, which is not posted here, that prevents a class from being added to the datastore if it already exists in the datastore.

calling "storeClass" appears to load and parse the class hbm.xml files.

Depending on the order that I add the classes to the datastore, I receive different errors including "unmapped class" and "no persister found for class" and others.

Thanks
-bnl

I just tested your mapping with Hibernate 2 and here there were no problems.

I think that at some point that was this limitation in hibernate 1.x - but i think you need to updated to 2.x before getting the better and simpler Configuration mechanism.

Gavin?

/max

Thanks. What is required to convert from v 1.2.x to 2.x?

Are there major or minor code changes and can u send a link to new docs?

Does v. 2.0 allow you to change the primary key that links a one-to-one relationship?

Thank you,
-bnl