Hibernate version: 3.0
Using Oracle 10g:

I'm new to Hibernate, and I like what I see so far, but I need some help with an odd data model.

This data model (inherited, non-negotiable) contains, among other tables, a virtually unbounded number of tables with the exact same structure and slightly different names. For example:

my_data_1
my_data_2
..
my_data_n

all have the exact same structure (in the actual database the names are not sequential, but you get the idea). The theoretical upper limit of n is roughly a billion. I'd like to load, update, save and delete objects for these tables using Hibernate, but I'd obviously rather not create a separate object and mapping file for each table, especially since part of the application creates these tables dynamically. The easiest solution (imho) would be for me to be able to specify the table name when I perform the load(), save(), update(), etc. operation, but I know I can't do that.

My alternative approach would be to create a template hbm.xml file and plug in the table name and create a new SessionFactory whenever I want to work with one of these tables. There are some obvious drawbacks to this approach, but I think it would work under very restrictive circumstances.

My question is, is there a better way to do something like this that I've missed in all of the Hibernate docs I've looked through (other than re-working the data model)?

You're absolutely right! Once the SessionFactory is alive, there's no way of changing the mapping anymore.

There's one thing to note: The creation of the session factory can take some seconds. If you have to recreate the session factory very often this could be a problem.

HTH
Ernst

I hope your "non-negotiable" data model doesn't say anything about adding new things to it? :) You can write your own store procedure to handle the ever changing table names, and map the SP as custom SQL statements.

See 17.4. Custom SQL for create, update and delete for details.

jd

Thanks, jd001982. While I was hoping to avoid writing SQL for these tables, I think this could be a workable fallback plan.

Although, if I need to set each value in the stored procedure call (e.g. with .setString(), .setInteger(), etc), it might be difficult to sell the use of Hibernate in this case over JDBC to my colleagues who are already familiar with JDBC. One aspect of these tables is that they are relatively wide (128 columns), so you can see how having to set each column value from the object is not attractive.

It's not clear to me whether I would need to ".setXXX" each value, but that's what it looks like from the doc. I'm going to search around for some examples that use the stored procedure approach.