Get Started with the .NET/C# Driver

Create a Project Directory

In your shell, run the following commands to create a directory called csharp-quickstart and initialize a .NET framework project for a new console application:

mkdir csharp-quickstart
cd csharp-quickstart
dotnet new console

Install the .NET/C# Driver

Run the following command to install the current version of the .NET/C# Driver as a dependency of your project:

dotnet add package MongoDB.Driver

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 into your Atlas account and navigate to the Database section and click the Connect button for your new deployment.

Proceed to the Connect your application section and select "C# / .NET" from the Driver selection menu and the version that best matches the version you installed from the Version selection menu.

Select the Password (SCRAM) authentication mechanism.

Deselect the Include full driver code example option to view the connection string.

Copy your Connection String

Click the 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.

Set an Environment Variable

In your shell, run the following code to save your MongoDB connection string to an environment variable. Replace <your MongoDB URI> with the connection string that you saved to a file in the previous step.

export MONGODB_URI="<your MongoDB URI>"

set MONGODB_URI="<your MongoDB URI>"

Storing your credentials in an environment variable is safer than hardcoding them in your source code.

Create your .NET/C# Application

Copy and paste the following code into the Program.cs file in your application:

using MongoDB.Driver;
using MongoDB.Bson;
var connectionString = Environment.GetEnvironmentVariable("MONGODB_URI");
if (connectionString == null)
{
    Console.WriteLine("You must set your 'MONGODB_URI' environment variable. To learn how to set it, see https://www.mongodb.com/docs/drivers/csharp/current/get-started/create-connection-string");
    Environment.Exit(0);
}
var client = new MongoClient(connectionString);
var collection = client.GetDatabase("sample_mflix").GetCollection<BsonDocument>("movies");
var filter = Builders<BsonDocument>.Filter.Eq("title", "Back to the Future");
var document = collection.Find(filter).First();
Console.WriteLine(document);

Run your Application

In your shell, run the following command to start this application:

dotnet run csharp-quickstart.csproj

The output includes details of the retrieved movie document:

{
  _id: ...,
  plot: 'A young man is accidentally sent 30 years into the past...',
  genres: [ 'Adventure', 'Comedy', 'Sci-Fi' ],
  ...
  title: 'Back to the Future',
  ...
}