Few years ago, I was working on one mongoDB project.Its a NoSQL database , easy to learn and its pure JSON based.
I learned it myself and had created a cheatsheet for it, so I can easily recall it anytime I want. It can help anyone who is interested in learning it quickly.
Thought to share the sheet. It can be found here :
https://github.com/kumarprd/mongo-guide/blob/master/my-mongo_guide.txt