Ask HN: How to build your own reporting tool?

For my thesis I'm going to build a Proof of Concept of a reporting engine but I don't know where to start. I have read about business intelligence tools a bit and that is the direction that I need to search but those all refer to existing tools. What I have in mind is a reporting tools like google analytics based on dimensions and metric to extract aggregated data from the database.

Any recommendations on literature about how reporting tools work? Or some talks about it on YouTube?