Hibernate version: 3.2.1 ga

I am opening two sessions in parallel and trying to update the same row in both the sessions. But I am not getting any exception even though I am doing concurrent modifications. Can somebody explain what I am missing here. I went through the 11 chapter in Hibernate tutorial and according to "11.3.2 Extended session and automatic versioning", Hibernate checks instance versions at flush time, throwing an exception if concurrent modification is detected.

Code between sessionFactory.openSession() and session.close():
SessionFactory sessionFactory1 = new Configuration().configure().buildSessionFactory();
SessionFactory sessionFactory2 = new Configuration().configure().buildSessionFactory();

session1 = sessionFactory1.openSession();
session2 = sessionFactory2.openSession();

Transaction tx1 = session1.beginTransaction();
Transaction tx2 = session2.beginTransaction();

Employee employee1 = (Employee) session1.get("com.test.hibernate.Employee", 1);
Employee employee2 = (Employee) session2.get("com.test.hibernate.Employee", 1);

System.out.println("Employee1 Name:" + employee1.getFirstName());
System.out.println("Employee2 Name:" + employee2.getFirstName());

employee1.setFirstName("joe1");
session1.save(employee1);
tx1.commit();

employee2.setFirstName("joe2");
session2.save(employee2);
tx2.commit();

Name and version of the database you are using:
Oracle 10g XE

Are your sesion1 and session2 truly different (and are your object instances different)?
Does your object have a 'version'? (mapping file would help).
(ususally, I have the oposite problem = stale data exception).

Oops, I should have noticed that:


Your session2.save(employee) is saving an object which has NOT been loaded by session2 - it was loaded by session1.
Perhaps you wanted to change and save en 'employee2'.

So, in your code, employee may be considered a 'detached' object (from the session2's point of view). Then the behavior depends great deal upon how you defined your object 'identity' -- I suspect there is something wrong there...

(Don't forget to rate this posting, if it happened to help).
Martin.

Sorry Martin. My mistake. I have corrected the code snippet. Please refer the same.

I am trying to save only employee2.

Well, then it's back to what is your versioning like.
Do you have it in your mapping file?
Is your get/set method for version working?
(assuming employee1 != employee2)

Thanks. Now I looked at the version element. Does it mean that I should add a version column in my tables (and in mapping file) wherever I need to avoid the dirty update?

My mapping is

<hibernate-mapping>
<class name="com.test.hibernate.Employee" table="EMPLOYEE">
<id name="empId" type="int" column="EMP_ID" >
<generator class="increment"/>
</id>
<property name="firstName">
<column name="FIRST_NAME" />
</property>
<property name="experience">
<column name="EXPERIENCE"/>
</property>
</class>
</hibernate-mapping>

Of course. You need property like Integer version in your object, and a column like VERSION int in your table.
Without it, Hibernate has nothing to check for.
Note special mapping for the version element in your mapping file:
<version name="version" type="integer" column="VERSION" />