The Forena module seems to me like a pretty perfect fit to address this requirement. No PHP coding involved, just add your custom SQL queries to fit your requirements for getting the data you need, and then use your XHTML / CSS skills to beef up your output (report). Eventually adding some charts to it also, which even support drill-down links.
Here is the intro near the top of that linked page (use the link for more details, and its child pages):
Forena Reports is built of the idea of using SQL to get data out of a
database and use XHTML and CSS to format it into web reports.
It is designed to leverage existing knowledge of HTML, CSS, SQL and
Its Supported database connections you'd want to take advantage of in this case would be either "Drupal" or "PDO" ... done! Don't believe me (yet), just try it in your own environment).
Be aware: I'm a co-maintainer of forena, and created most of the community docu for it.