Ask HN: How do you manage long list of emails?

I have 2 databases, one for registered users and one for all purchases ever done. I get an updated csv weekly for each one, yeah I know.

I'm looking for an easy to use tool where I could load both csv files and visually do queries to answer questions like:

"Show me all emails from registered users that completed purchases in the last 30 days"

or

"Show me all users that never purchased anything"

Currently I load these 2 in a database and perform queries manually. Another colleague just load them on Excel and do lots of VLOOKUP calls.

Is there a tool available to do this kind of analysis quickly and easy, preferably visual?