Ok.. so I'm happy that hibernate will be fine in my multi-database environment.. I can just provide my own connection.

However

What if... (and please don't talk to me about this design.. it's not my doing)

What if we have (lets make it simple) two databases and a table in database 2 has a foreign key to a table in database 1.. so a SQL statement might be

SELECT * FROM db2.customer, db1.address WHERE customer.addressId = address.id;

Or something similar..

Could I just refer to the tables in the "central" DB1 as db1.address (for example) when defining my mapping? If so, it doesn't matter what connection I pass to the sessionfactory right?

This is my last niggle before using hibernate..

What do you mean by "database"? Is this MySQL?

Yes - sorry should have mentioned that!! MySQL 4

Yeah, it works, I think. Just specify the database name using the schema attribute in your mappings. Its not really a schema, so note that SchemaExport gets confused if you try to use the notion of a "schema" to represent the MySQL notion of a "database", but the Hibernate core works fine.

We need to add a notion of "catalog" (I *think* that is the ANSI standard work for what MySQL calls "database), for the benefit of SchemaExport.

From what I've read, SchemaExport attempts to create something like a DDL file to create the various tables? Although this would work with our core tables, it wouldn't be possible to genereate the account "catalogues" anyway becuase they are dynamic.. I guess you could recreate existing catalogues if you could inform SchemaExport of their existence but there are over 1000 of them...(and one more generated each time a new account is opened)

It's a tricky design and one that I have mixed feelings about. I can see why it was done - for future scalability and speed.. but it sure makes my life hell!

-M-

eh??

You don't have to use SchemaExport if you already have existing tables, obviously.

:) That's not quite what I meant but it's not important.. suffice to say, the SchemaExport isn't of great use to me.