Hi,

I have two classes with one to many relationship, let's say Parent and Child.

I used the following method to load the Parent from DB

Parent parent = getHibernateTemplate.get(Parent.class, parentId);

Then I created a new Child and set its parent property

child.setParent(parent);

Finally, I tried to save the child with the following code:

getHibernateTemplate.merge(child);

At this point I got the following exception:
org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: Parent

The thing that I couldn't understand is I just loaded the parent obj from DB, how could it become transient?

I can make that exception disappear by setting the @ManyToOne(cascade=CascadeType.ALL), but that ends up with duplicate Parent objects being saved into the DB.

Thanks for any help.

The Exception disappeared after I removed the @Version field.