Hi,

I am confused when using hibernate many-to-one mapping.

I have a table with two columns refer to a same table. The relations are like the following:
<class name="Position" table="Position">
...
<many-to-one name="currentDepartment" column="CurrentDepartment" class="Department" />
<many-to-one name="previousDepartment" column="PreviousDepartment" class="Department" />
</class>

<class name="Department" table="Department">
<id name="departmentId" type="java.lang.String">
<column name="DepartmentID" />
<generator class="assigned" />
</id>
....
</class>

When previousDepartment and currentDepartment has the same departmentId, I get the same instance
of Department. So when I try to update currentDepartment, the previousDepartment is also updated.
How can I set the hibernate config to avoid this situation which means I want to update data separately.


Thanks!

Anyone can help?

Doesn't that mean they are the same department, from the same row in the database?

That's object-oriented programming for you:
if currentDepartment and previousDepartment are (one and) the same, you can't change properties of the former without affecting the latter (they are the same).
So if you want to set a new currentDepartment, you have to create a new Department (via new Department()) or retrieve an existing Department from the DB and set currentDepartment to that new instance.

You could even load, evict, set the id to zero, and save again. :)