Hi, I'm an asp.net developer that works for a largish company supporting primarily internal customers.  My group builds custom one-off applications to facilitate business work-flows such as invoicing.  A typical invoicing app would consist of an interface to a database modeling line item objects with labor and direct expense fields , a foreign key relation on an invoice, and invoice objects.  There's other primary key tables relevant to this process, but beyond the scope of the scenario I'm setting up.

My question is basically, can DotNetNuke drive such a data-driven web application? 

• Can I create modules that use linq to sql or linq to entities with connections to databases other than the DNN database containing the Host/Portal membership and CMS data? 
• Would I need to write discreet modules for every business data interface the user requires, or is there some other way of including this kind of functionality in a DNN portal without writing modules for every custom data-driven function in a web application?  (for example, BlogEngine.Net allows UserControls to be injected with a syntax similar to BBCodes.)
• If it is possible to create such data-driven modules, how are data values passed between modules?  Using the above example, say I want to create a page listing invoices, and a function that redirects users to a line item list page in response to invoice selection.  Is there a "best practices" way of accomplishing this from within DNN?  Can modules use session and query string parameters?
• Is DotNetNuke a good solution for abstracting away all the stuff every app requires such as membership so that I can concentrate on the core business logic of the app?
• If not, is there another framework that's flexible enough to support custom data stuff while offering similar convenience for more common functionality?

For a while now I've become worn out writing apps because I feel like I've been building with molecules when I could be building with bricks.  I'm trying to figure out if DotNetNuke is the answer to my problem.

Thanks!
Gabe

Thanks for the reply!

It's been difficult, but I spent a lot of hours over the weekend working on reimplementing a site I've been working on for a while in DNN.  I've actually spent a good amount of time at the site you linked :)

The module development has been challenging, and I'm not certain everything I've done is "best-practices" but I've succeeded in creating a module package that uses XMLMerge to add asp.net Data Visualization configuration items into the host web.config, creates some tables, stored procedures, and UDFs in the site DB, uses Linq to SQL for the DAL, and adds two controls with two different graphs as two separate modules within the module definition.

I also learned how to set up the module development environment such that it's a distinct solution within in /DeskTopModules/ and to debug it by attaching it to the iis worker process.

I think I hit on some pretty hard core stuff there and so far I'm impressed.  I really like that I created a whole site with custom data, look & feel, membership, blog, and forum over the space of a weekend.  If I had to write this from scratch it would have taken me months and still come up short on quality compared to DNN.