Introduction

MongoDB is an open-source schemaless document database. It's very popular and often referred to as the leading NoSQL database.

The advantage of working with a document database is that you can work with JSON-style documents, and its functionality can be accessed directly through JavaScript notation. Also, the need for expensive joins is reduced.

JSON

JSON (JavaScript Object Notation) is a text format built on two universal data structures, supported in any form in all modern programming languages:

• A collection of key/value pairs (object) { string : value, string : value }
• An ordered list of values (array) [ value, value ]

A value can be a string in double quotes, a number, true, false, null, an object or an array. Those structures can be nested.

Source

Syntax example

Differences with Relational DBMS

The folowing table illustrates in a sim MongoDB's main differences with relational databases:

RDBMS	MongoDB
Table	Collection
Column	Key
Value	Value
Record/row	Document/object

MongoDB is flexible: you can have a collection of Users with an entry (document) with First name and Last name, and then another entry with First name, e-mail address and date of birth. The only requirement for each document is a unique ID number (_id) which Mongo will automatically assign to each document object (although it's not recommended, you could instead set a custom ID).

Installation

We'll see how to easily install and run MongoDB

Download and set-up

MongoDB (community server) can be downloaded here

MongoDB requires a data directory to store data. By default, this directory is \data\db on the same drive from which you start MongoDB. This folder can be created in a Command Prompt with mkdir \data\db.

An alternate path for storing the data files can be defined with "C:\Program Files\MongoDB\Server\3.4\bin\mongod.exe" --dbpath D:\test\mongodb\data being --dbpath the directory in which you'll save the DB.

Starting MongoDB and connecting

MongoDB can be started running mongod.exe

We can try to connect to MongoDB through the mongo.exe shell, executing it from another Command Prompt

Another useful possibility to interact with the database is using the utility Robomongo, which can be downloaded here

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Sources

Install MongoDB

More information in the Official documentation

Highly recommended video: MongoDB for beginners