I am surprised this isn't mentioned yet, but Prolog makes a very acceptable query language. Although I think in that version it is called 'Datalog'. http://en.

I am surprised this isn't mentioned yet, but Prolog makes a very acceptable query language. Although I think in that version it is called 'Datalog'. http://en.wikipedia.org/wiki/Datalog http://en.wikipedia.org/wiki/Datalog It is obviously much different than SQL. There are actually quite a few implementations of it if you look at that wikipedia page. The queries end up being much more declarative than anything you'd do with SQL. Pretty much you ask the database a question, and it returns an answer (which is awesome).