I'm exploring whether to go with DNN. One thing I'd like to do is be able to query a database; one project, for instance, would be to Have clients rate the effectiveness of a range of treatments and Input Cost, Brand name, rate side effects, etc as well as their gender, illness severity, duration, etc. and then do queries like: top rated treatments over all top rated treatments in a specific category top rated treatments for severely ill, moderately ill - this sort of thing etc. Can I do this with DNN?

And if so - what modules would be most appropriate? Thanks!

Yes, you can do that.

I would recommend looking at the DotNetNuke Form and List module and Data Springs Dynamic Forms module.  You can present a form/questionnaire to a user and capture the results in a database table.  Then you can run queries on the resulting table for reports.  Dynamic Forms include conditional parts of the form, multi-part forms, etc.

For reporting I would look at Form and List, Reports, and SGSV from tressleworks.ca.  The latter has some nice filter and drill down parts if you want to do some interactive reporting.

Look at these tutorials:

User Defined Table (UDT) DotNetNuke Core Module  (the older version of Form and List)

• DataSprings Dynamic Forms Quick Start Guide
• DataSprings Dynamic Forms Question Events
• DataSprings Dynamic Forms Data Management
• DataSprings Dynamic Forms Completion Events
• How to Create an Email Opt-In Form with a Third Party Email Service (AWeber) using DataSprings Dynamic Forms