It would be nice if I could use only one SessionFactory to work with many databases; obviously I mean many databases on the same database server and with identical schema.

I think to define one Configuration and obtain a SessionFactory from it; after that, obtain Session from the SessionFactory providing the JDBC Connection to the choosen database (even if I'm not very happy to provide connection...).

But ...
Is this working correctly?
And, if it is possible, is there a best approach?

Thanks

I might be corrected by one of the Admins, but I believe that the rules is simple, only one SessionFactory per Database, as it in essence represents control of all the various sessions that will act on that database.

As such, each SessionFactory has its own config and sets of mapping files. I have a Database class where I map to 8 different databases using 8 different SessionFactories.

It could also be seen as good practise to keep different DB configurations nicely separated.

-G

First of all, thank you very much for replying so quickly.

From the point of view of a good design, I absolutely agree with you.
At the moment I'm starting a new project with a database schema that will have more or less one hundred of quite big tables; and the application require to have different databases built on the same schema (the business logic is the same, of course).
Since I read from documentation that a SessionFactory is a "hevy" object, that contains all mappings and statements, I would like to know if this approach was possible.

Thank you very much, Brannor

Some of my databases are the same, i.e. same table names, same tables, etc. except on different machines. To do this is a bit of a drag, in that you basically copy all the mapping files to a new directory, and change a few minor settings. The nice thing is though, that all the different mapping files can use the exact same Java objects, so you can quite literally load an object (row) from on SessionFactory, and save that very same object into another SessionFactory.

I understand what you would like to do, and if the tables are the same, and the logic the same, then you can create methods which accept some form of identifier for which database you want to work with (a variable) and have a central Database class that takes that variable and knows which session factory to use, that way, the same workflow can be used on multiple databases.

I hope that's not too confusing.

As I like showing people, it's really nice to be able to load one object tree from one database (SessionFactory), and simply tell it to save the entire tree into another database (SessionFactory), and that all in a few lines. :)

-G

Absolutely clear; I think I will create this class Database, holding all SessionFactory, and bound it to a JNDI resource or simply to an application context param in the servlet container.



You are right. Hibernate is performing magic...


Bye