C# quick start

At the end of this guide, you will have created a simple . NET console Hello, World! program that connects to the Memgraph database and executes simple queries.

Prerequisites

If you're new to Memgraph or you're in a developing stage, we recommend using the Memgraph Platform. Besides the database, it also includes all the tools you might need to analyze your data, such as command-line interface mgconsole, web interface Memgraph Lab and a complete set of algorithms within a MAGE library.

Ensure Docker (opens in a new tab) is running in the background. Depending on your operating system, execute the appropriate command in the console:

For Linux and macOS:

curl https://install.memgraph.com | sh

For Windows:

iwr https://windows.memgraph.com | iex

The command above will start Memgraph Platform, which includes Memgraph database, Memgraph Lab and Memgraph MAGE. Memgraph uses Bolt protocol to communicate with the client using the exposed 7687 port. Memgraph Lab is a web application you can use to visualize the data. It's accessible at http://localhost:3000 (opens in a new tab) if Memgraph Platform is running correctly. The 7444 port enables Memgraph Lab to access and preview the logs, which is why both of these ports need to be exposed.

For more information visit the getting started guide on how to run Memgraph with Docker.

Driver

Please note that the code samples in this guide utilize the Neo4j.Driver.Simple package which implements a blocking interface around the 'main' driver. It should be used as a tool for getting started quickly. The Neo4j.Driver package contains the official and complete driver for real-world projects. The driver documentation can be found here: Neo4j . NET Driver (opens in a new tab).

The Blueprint41 (opens in a new tab), .NET ORM, also supports Memgraph. Blueprint 41 supports the definition of the object model as a schema. It offers refactoring scripts written in CSharp, which you can add to your project. When you run your program with an older graph version, the upgrade script will automatically be executed against the graph. It also supports the generation of type-safe data objects, so you know at compile time if your code is compatible with the latest upgrades.

Basic Setup

We'll be using Visual Studio 2022 on Windows 10 to connect a simple . NET console application to a running Memgraph instance. If you're using a different IDE, the steps might be slightly different, but the code is either the same or very similar.

Let's jump in and connect a simple program to Memgraph.

1. Open Visual Studio and create a new project.
2. Find and select the Console App (. NET Core) template by using the search box.
3. Name your project MemgraphApp, choose an appropriate location for it, and click Create.
4. Select the Tools > Manage NuGet Packages menu command.
5. Once the window opens, search for the Neo4j.Driver.Simple.
6. Select the appropriate driver and click Add package.

Now, you should have the newest version of the driver installed and can proceed to copy the following code into the Program.cs file.

using Neo4j.Driver;
 
namespace MemgraphApp
{
    public class Program
    {
        public static void Main()
        {
            string message = "Hello, World!";
 
            using var _driver = GraphDatabase.Driver("bolt://localhost:7687", AuthTokens.None);
            using var session = _driver.Session();
 
            var greeting = session.ExecuteWrite(tx =>
            {
                var result = tx.Run("CREATE (n:FirstNode) " +
                                    "SET n.message = $message " +
                                    "RETURN 'Node '  + id(n) + ': ' + n.message",
                    new { message });
                return result.Single()[0].As<string>();
            });
            Console.WriteLine(greeting);
        }
    }
}

Once you run the program, you should see an output similar to the following:

Node 1: Hello, World!

Alternative Setup

If you want to try out more complex operations, feel free to use the refactored code below.

using Neo4j.Driver;
 
namespace MemgraphApp
{
    public class Program : IDisposable
    {
        private readonly IDriver _driver;
 
        public Program(string uri, string user, string password)
        {
            _driver = GraphDatabase.Driver(uri, AuthTokens.Basic(user, password));
        }
 
        public void PrintGreeting(string message)
        {
            using (var session = _driver.Session())
            {
                var greeting = session.ExecuteWrite(tx =>
                {
                    var result = tx.Run("CREATE (n:FirstNode) " +
                                        "SET n.message = $message " +
                                        "RETURN 'Node '  + id(n) + ': ' + n.message",
                        new { message });
                    return result.Single()[0].As<string>();
                });
                Console.WriteLine(greeting);
            }
        }
 
        public void Dispose()
        {
            _driver?.Dispose();
        }
 
        public static void Main()
        {
            using (var greeter = new Program("bolt://localhost:7687", "", ""))
            {
                greeter.PrintGreeting("Hello, World!");
            }
        }
    }
}