Is it possible to create a entity bean(CMP) on a data base view?
It is not possible. but if u want to do this so that u can make a query on multiple table, better use toplink or cocbase.
All I will say is for Oracle, I do not know for other database vendors.
If you want to use CMP, I am not sure, but why not? I have experimented that on IBM VAJ environment with Persistent Builder. I created a table, declared that I was mapping on a table, then dropped the table and created a view with the same name and columns. And that worked fine.
If you want to use BMP, not problem if you do not access to a view defined with a join (otherwise you will not be able to update data).
Related to the previous email, we have tried to use Cocobase (TopLink is too expensive!) and experiment major problem with transactional support. If you want a full transactionnal support with Cocobase, you must replace your vendor EJB container, by the Cocobase EJB container: not sure it is a good idea.