Query on Facade Pattern

Hi

I am using the Facade Pattern to create a web application in Struts.

I've got 3 sets of classes:

Database classes to fetch data from the database

Action Classes to display data on the web interface

Facade class which uses objects of the database classes and gives a set
of functions to the Action Classes.

Should I create the objects of the Database classes directly in the
Facade class or should I use an interface for the Database classes in
the Facade class?
I want to do this so that if I want to use any object of the Database
class directly in the Action Class(through the Facade Class that is...)
then I dont have to access the Database Class Objects directly in the
Action Class.