I'm currently evaluating hibernate and trying to map it to some preexisting database tables. It's going quite well but I've come aacross an interesting problem...

I've got this table that has about 6 columns in the composite-id.
The group of 6 when combined must be unique.
Each of the fields may be null. That is a valid case.
I need to be able to query the table using a where referenceing any column. But, when I do this, hibernate runs my query ok, gets a result and tries to load the non-key fields by running a subsequent query using the key values found in the first query. Some of these fields are null and it fails to find the matching row.

Is this a case where hibernate won't be a good fit?
If hibernate can do this, I'll need some help.

Thanks a bunch
Carl

It seems that I can get results from this sort of query if I use query.list() instead of query.iterate(). Now I have conserns that I probably won't be able to update rows where key fields are null. I'm not sure but I'm going to give it a try.

Carl

As I expected, I am not able to update the objects returned in the query.list() call.
The update statement executes and I get no errors, but the data isn't changed because no record matched the where clause.
the where clause looks like where field1 = ? and field2 = ?....
But, since some of the values are null, it's not doing the right thing.
Is there a way to fix this? I know, don't have nulls in your key fields. Not my choice right now.
Perhaps the update-sql feature. Is that in the latest source? I'll have to build hibernate?

Enyone?

Thanks
Carl

Ideally what I'd be looking for is the where clause that hibernate generates to look more like.... field1 = ? and field2 is null and fie...

Perhaps something I'll have to write?

Null's as possible in elements of the composite key - OUCH bad. You should change the schema. Although you will say the powers will not allow you to.

Exactly right, I'm working with an existing database structure and don't have that flexibility.

After looking through the hibernate source and actually stepping through it with a debugger, I think I will not be going to hibernate soon. The where clause that selects an object by the id is pretty fixed at being just = ?. And the code that writes this sql doesn't readily have visibility to the id values to test them for null.

Maybe someday I'll manage to return to hibernate, but for now it looks like I'm stuck with bean managed persistence.

Thanks
Carl