Getting Started with MongoDB: The Complete Beginner‘s Guide

Hey there! Looking to learn MongoDB but don‘t know where to start? You‘ve come to the right place. As a developer and MongoDB expert, I‘ll be walking you through everything you need to know to get started with this super popular document database.

Content Navigation show

In this comprehensive beginner‘s guide, we‘ll cover:

  • What is MongoDB?
  • Core Features and Benefits
  • Installing MongoDB
  • Importing and Querying Data
  • Core Concepts
  • Data Modeling
  • GUI Tools
  • Advanced Features
  • Resources for Learning

So buckle up and let‘s get started!

What is MongoDB?

MongoDB is a popular open-source NoSQL document database. While traditional SQL databases store data in tables with predefined schemas, MongoDB stores unstructured data as BSON documents (JSON-like format with extensions).

Some key things to know about MongoDB:

  • Schema-less – No predefined schemas makes it very flexible
  • Document Oriented – Data is stored in documents similar to JSON
  • High Performance – Integrated caching and optimizations
  • Scalable – Easy horizontal scaling with sharding
  • Flexible Data Model – Embed related data in documents
  • Rich Query Language – Powerful operators for queries
  • High Availability – Replica sets for auto-failover

With these capabilities, MongoDB is great for content management, real-time analytics, mobile apps and many other use cases involving dynamic schemas and large volumes of data.

Major companies like eBay, Cisco, Adobe, Docker and IKEA are powered by MongoDB.

MongoDB Editions

There are a few different editions available based on your needs:

MongoDB Community

The free open-source edition ideal for early development and prototyping. Easy to setup but lacks enterprise-grade security and scalability.

MongoDB Enterprise

Paid version with advanced security, automation, cloud management and other enterprise features. Comes with official support subscriptions.

MongoDB Atlas

Fully managed MongoDB cloud service so you don‘t have to worry about operations and scaling. Has a free tier to get started.

Now let‘s go through installing MongoDB Community edition on your own machine…

Installing MongoDB

The installation process varies slightly across operating systems. I‘ll cover the steps for the most common OSes:

Windows

On Windows, grab the msi installer from mongodb.com:

Run the installer and follow the setup wizard to install MongoDB under Program Files. Make sure to install MongoDB Compass during the setup for the GUI.

Next, create the data directory. Open Command Prompt as Administrator and run:

md \data\db

Then start the mongod service:

"C:\Program Files\MongoDB\Server\4.2\bin\mongod.exe" --dbpath=\data\db

That‘s it! MongoDB is now running on port 27017.

MacOS

On Mac, we‘ll install from Homebrew which makes it very quick:

brew tap mongodb/brew
brew install mongodb-community

To run the MongoDB server:

mongod --config /usr/local/etc/mongod.conf

It automatically uses /usr/local/var/mongodb as the data directory.

Linux

On Linux, download the tarball from mongodb.com and extract it:

tar -zxvf mongodb-linux-*

Launch the daemon to start the DB:

./mongod --dbpath /var/lib/mongo

The data is stored under /var/lib/mongo by default.

With MongoDB installed, let‘s start interacting with it!

Importing and Querying Data

We can manage data in MongoDB via:

  • mongo Shell – Command line tool for admin access
  • Compass GUI – Visual interface for exploring data
  • Driver Code – For app dev in Node, Python, Java, etc

Let‘s import a sample dataset and query it in the shell.

First connect to the mongo shell:

mongo

Now switch to a new DB called videoStore:

use videoStore

Next, download the sample JSON dataset from media.mongodb.org and import it:

mongoimport -d videoStore -c movies --drop --file /path/zips.json

We now have a movies collection loaded with video rentals data we can query!

Some example queries:

Find all movies released in 2012:

db.movies.find({ "year" : 2012 })

Count all movies with a runtime over 120 minutes:

db.movies.count({ runtime: { $gt: 120 } })

Filter movies by release year and projection only title and rating:

db.movies.find(
   { year: 2010 },
   { title: 1, rating: 1 } 
)

As you can see we can easily filter and project specific fields from documents using MongoDB‘s rich querying syntax!

Now let me introduce you to some core concepts before we continue…

Core Concepts

Documents

The basic data entity in MongoDB is a document, which is a set of key-value pairs similar to JSON:

{
   name: ‘John‘,
   age: 30,
   hobbies: [‘guitar‘, ‘tennis‘],
   address: {
      street: ‘123 Main St‘,
      city: ‘Anytown‘,
      state: ‘CA‘
   }
}

Documents don‘t enforce any schema which provides great flexibility.

Collections

Documents are stored in collections which are equivalent to tables in relational databases. Unlike tables however, different documents can have completely different fields in the same collection.

Database

A database holds one or more collections of documents. It provides the administrative boundary for access control, indexing, replication etc.

_id Field

Every document stored requires a special _id field that acts as the primary key. If not provided, MongoDB auto generates a unique ObjectId.

These are the main concepts to understand. Now let‘s look at data modeling tactics…

Data Modeling

A key advantage of MongoDB is dynamic schemas that allow embedding related data in documents rather than normalizing across tables.

For example, here is how we can model a blog using embedding vs references:

Embedded Data

{
  title: ‘Top 10 Databases‘,
  content: ‘MongoDB is the most popular...‘,
  comments: [
     {
        user: ‘john‘,
        text: ‘Great article!‘, 
        date: Date() 
     }
  ],
  tags: [‘mongodb‘, ‘sql‘, ‘postgresql‘],
  author: {
     name: ‘Kate‘,
     bio: ‘Writer. Tech geek.‘ 
  }
}

Referenced Data

{
  title: ‘Top 10 Databases‘,
  content: ‘MongoDB is the most popular...‘, 
  tags: [‘59a63eb2cdf655467953b522‘],
  author: ‘592ae1cdfc13ae7d6c000001‘
}

References involve normalized, separate collections with IDs rather than embedded documents.

There are tradeoffs to each approach that require thought around data access patterns and growth for scalability.

Now let‘s look at Compass for a friendlier interface…

MongoDB Compass

While the mongo shell is great, MongoDB Compass provides an intuitive GUI alternative:

Compass allows you to:

  • Explore and filter documents visually
  • View indexes, explain query plans
  • Analyze performance in real time
  • View schema and validation rules
  • Insert, update, delete documents

It‘s a very helpful tool for data analysis and querying without having to write code.

Other popular GUI options include MongoDB Charts, UIs like AdminMongo and Robo 3T.

Okay, we‘ve covered the basics – now let‘s discuss some more advanced functionality MongoDB offers…

Advanced Features

Here are some powerful features that make MongoDB very appealing for mission critical systems:

Indexing

Proper indexing is critical for fast lookups and sorts. MongoDB supports secondary indexes on any field similar to other databases.

Aggregation Pipeline

The aggregation framework provides powerful methods for data analysis and preprocessing like groupby’s, pivots and much more with great performance.

Replication

MongoDB replication allows maintaining multiple copies of data for redundancy and automatic failover. Read replicas also help scale out reads for heavy workloads.

Sharding

Sharding partitions data across clusters allowing horizontal scaling for massive data loads. Auto-balancing prevents hotspots.

Transactions

ACID transactions provide atomicity and isolation for complex multi-document updates. Requires a replica set to function.

Plus many more capabilities for administration, monitoring, cloud deployments and integrations.

I think that covers most of the critical topics for an introduction. So where do you go from here?

Learning Resources

Here are my top recommendations for further learning:

Online Courses

Excellent video courses from MongoDB University and sites like Udemy

Certification

Professional certification for MongoDB to validate your skills

Books

Read the definitive guide and other great books for deeper dives

MongoDB Manual

Official MongoDB manual with extensive docs and tutorials

Community Forums

Ask questions and help others on MongoDB forums and Stack Overflow

So that wraps up this complete beginner‘s guide! We covered what MongoDB is, how to install and use it, data modeling, tools and more.

I hope this gives you the perfect starting point for becoming an expert. Now go forth and build awesome apps powered by MongoDB!

Let me know if you have any other questions. Happy to help out beginners get started with MongoDB.

Tags: