Get Started with the Ruby Driver

Install dependencies

Before you begin developing, ensure you install Ruby version 2.7 or later in your development environment. Ruby is pre-installed on macOS and some Linux distributions, but you might need to update your version.

Create a project directory

Run the following command in your shell to create a directory called ruby-quickstart for this project:

mkdir ruby-quickstart

Then, run the following commands to create a quickstart.rb file in the ruby-quickstart directory:

cd ruby-quickstart
touch quickstart.rb

Add the Ruby driver to your project

Open the quickstart.rb file and add the following code:

require 'bundler/inline'
gemfile do
  source 'https://rubygems.org'
  gem 'mongo'
end

This code adds the Ruby driver as a dependency by using the Bundler dependency management tool.

Create a free MongoDB deployment on Atlas

Complete the Get Started with Atlas guide to set up a new Atlas account and load sample data into a new free tier MongoDB deployment.

Save your credentials

After you create your database user, save that user's username and password to a safe location for use in an upcoming step.

Find your MongoDB Atlas connection string

To retrieve your connection string for the deployment that you created in the previous step, log in to your Atlas account and navigate to the Clusters section. Then, click the Connect button for your new deployment.

Proceed to the Connect your application section. Select "Ruby" from the Driver selection menu and the version that best matches your installed version from the Version selection menu.

Copy your connection string

Click the copy button on the right of the connection string to copy it to your clipboard, as shown in the following screenshot:

Update the placeholders

Paste this connection string into a file in your preferred text editor and replace the <db_username> and <db_password> placeholders with your database user's username and password.

Save this file to a safe location for use in the next step.

Edit your Ruby application file

Navigate to your quickstart.rb file in the ruby-quickstart directory. Copy and paste the following code below the Bundler code from the Download and Install step of this tutorial. This code connects to MongoDB and queries the movies collection in the sample_mflix database.

uri = '<connection string>'
begin
  client = Mongo::Client.new(uri)
  database = client.use('sample_mflix')
  movies = database[:movies]
  # Queries for a movie that has the title 'Back to the Future'
  query = { title: 'Back to the Future' }
  movie = movies.find(query).first
  # Prints the movie document
  puts movie
ensure
  client&.close
end

Assign the connection string

Replace the <connection string> placeholder with the connection string that you copied from the Create a Connection String step of this tutorial.

Run your Ruby application

From your ruby-quickstart directory, run the following shell command to run the application:

ruby quickstart.rb

The command line output contains details about the retrieved movie document:

{"_id"=>BSON::ObjectId('...'), "plot"=>"A young man is accidentally sent
30 years into the past in a time-traveling DeLorean invented by his friend,
Dr. Emmett Brown, and must make sure his high-school-age parents unite
in order to save his own existence.", ...
"title"=>"Back to the Future", ...

If you encounter an error or see no output, ensure that you specified the correct connection string in the quickstart.rb file and that you loaded the sample data.