Hi everybody !

I'm programming a VFP (version 6 SP 4) application. I do the UI and what I call the Engine for my database. I mean that I would like the UI program to be independant from the program that does the work directly on the database (Engine).

In that way, another programmer who does the e-commerce web site would be able to instanciate my engine, than call the CreateInvoice method, for example, giving me the parameters I want to create the invoice. My UI will use the same object so the code will be written in one place (Engin) only and no other programmer will touch the database directly so I will keep the control on it.

The way I'm doing this right now is with SQL pass-through and a COM server. My idea is to have a COM server connected on the database and my UI connected on the database also. For viewing data, my UI will create cursors to display information, but the modification will be done by my COM server. I mean that every validation or SQL query that modifies the database will be done by my COM server.

Here's my question : Is it a good way to do things ? If not, what is the best way ? (Maybe I should specify that I would like my code to be able to work even with VFP databases, SQL server or ACCES). Is the fact of having a UI and a COM server connected to the database need 2 SQL server licenses ?

Thanks for your advices...