A cheat sheet for mongoDB commands and queries.

MongoDb.md

Mongo DB

Shell Commands

• List all databases:

db.getMongo().getDBNames();
show databases
show dbs

• Change databases

use <DB_Name>

• List all collections

db.getCollectionNames() // returns an array
show collections        // returns a clean output

Ruby Mongo Driver

installed mongoid with: gem install mongo

require 'mongo'

client = Mongo::Client.new([ '192.168.99.100:32776' ], :database => 'development_db')

c = client.database.collection_names
puts "\nAll Collections: #{c}\n"

customers = client[:customers] # Assume have array collection customers
# get all customers in an array format
c_array = customers.with(:read => { :mode => :primary_preferred }).find.to_a
puts "\ncustomers Array: #{c_array}\n"