2 post: JDBC and multiple databases

I would like to create a report about Domino databases through JDBC.

A Simple Join is the process of forming pairs of rows from multiple tables by matching the contents of the fields listed in the WHERE clause.

Can I write a join from multiple databases ?

Example:

This code work if the Order and the Invoice Forms are in the same database.

SELECT * FROM Order, Invoice

WHERE Order.DateComposed=Invoice.DateComposed AND Order.Subject=Invoice.Subject

Can I do anything as like this ( Form Order in database DbOrder.nsf and Form Invoice in database DbInvoice.nsf) ???

SELECT * FROM DbOrder.nsf/Order, DbInvoice.nsf/Invoice

WHERE DbOrder.nsf/Order.DateComposed=DbInvoice.nsf/Invoice.DateComposed AND DbOrder.nsfOrder.Subject=DbInvoice.nsf/Invoice.Subject