MongoDB
From Wasya Wiki
Install MongoDB on ubuntu
From: https://docs.mongodb.org/manual/tutorial/install-mongodb-on-ubuntu/
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv EA312927 echo "deb http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.2 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.2.list sudo apt-get update -y sudo apt-get install -y mongodb-org
Count Documents
db.collection.aggregate( [ { $group: { _id: null, count: { $sum: 1 } } } ] )