Hibernate version: 2.1.7

Mapping documents:

<class name="Folder" lazy="true">
<id name="ID">
<generator class="native"/>
</id>
<version name="version"/>
...
<map name="attributes" cascade="all-delete-orphan" lazy="true" table="folder_attributes">
<key column="id"/>
<index column="key" type="string"/>
<element column="value" type="string"/>
</map>
</class>

Code between sessionFactory.openSession() and session.close():

session.beginTransaction();
...
Folder folder = session.get(...);
...
folder.getAttributes().remove("abc");
transaction.save(folder);
transaction.commit();



This snip is from a webapplication we're writing where for each http request a session is opened, a transaction is created, objects are read from the session, manipulated and saved to the session.

My problem is that:

1. When I try to remove key/values from the attribute map, nothing is changed to the database (the folder object is however written to the database as I can see from the debug logs).

2. When I try to update a key/value pair in the attribute map (by changing the value part for example), hibernate executes an insert statement (which fails the uniqueness constraints).

3. When I add a key/value to the attribute map, everything works fine!

Interestingly, when I keep the session open (i.e. ensure that only one user is hitting the webapp and keep the same session object open all the time) then changes to the attribute map are saved as expected.

Any thoughts?

G.

Sounds like a broken session-handling to me. Also a cascade setting for a map with <elements> does not make much sense.

Dear Michael, thank you for the quick reply!

I set lazy to false and changed cascade to none, but that didn't help much.
You say you're suspecting a broken session. I'm using the default connection pooling (i.e. not any application server database pools). Do you have any advice on how to track down what is happening?

BR
G.

I said broken session handling - if you can solve the problem by the way you handle your session, most likely the way you do it currently is messed up

Helo again

I must apologise for the initial post, as I did a bad test. In fact, operations on the collection perform erratic and in a non predictable way even if used in a single-shot example, like:


which I run from the command line (so no application servers or anything).
The folder table initialy looks like:


and after the program has finished is exactly the same, the delete operation is not performed.

Any hints?
G.

Dear Michael

I think I found what was wrong. When a key exist, but the value is null then hibernate gets confused about which keys exist and which don't. Or, alternatively, I just don't know how to play with non-null constraints :)

Eitherway, thank you for your help!
BR
G.