Select distinct on 2 keys in mongodb?

Is is possible to select Distinct on 2 or more keys in mongoDB? All the examples I've found only show 1 but I'd actually want开发者_开发百科 to do a distinct on 2.

All the examples I've found only show 1

For exactly this limitation....what you want or get are two completely different things. If you need this functionality: implement a merger inside your application code.