Is JPA an appropriate ORM for this scenario?

We have a central database for accounts. It contains login information, and a field called database profile. The database profile indicates what database connection should be used for the account. For example, we would have Profile1, Profile2, Profile3... ProfileN

If a user is indicated to have Profile1, they would be using a different database than a user who is indicated to be a part of Profile2.

My understanding of JPA is that you would need a new EntityManagerFactory for each Profile (Persistence Unit), even though the databases all have the same schema开发者_如何学Python, just different connection information. So if we ended up having 100 profiles we would have 100 Entity Manager Factories, which doesn't seem ideal.

I've looked into the EntityManagerFactory, and it doesn't seem to let you change the database connection options.

Is my only option to have N EntityManagerFactory's, and if so would their be be any major consequences to this (such as bad performance)?

Thanks for any advice.

The kinds of things you're talking about are getting out of the scope of the JPA abstraction. Things like specific connection management are generally more provider specific. For example, with Hibernate SessionFactory you can certainly create new sessions from an aribtraty JDBC connection. There would be pitfalls to consider such as ID generation schemes (you'll probably have to use sequences generated in the DB), and you're basically hooped for L2 caching, but with careful programming it could be made to work.

Just use javax.persistence.Persistence#createEntityMananagerFactory(String,Map), and provide in the Map the connection parameters. Cache the EMF, and use the connections judiciously, don't mix n match object from the different EMFs.

If you are using spring then I know there is a way to dynamically switch the DataSource. Find more information here