Performing CRUD Operations Using EventStoreDB in .NET

Introduction

EventStoreDB, a powerful database designed for event sourcing, allows developers to store events as a sequence, enabling a robust system for storing and retrieving data. When it comes to implementing CRUD (Create, Read, Update, Delete) operations with EventStoreDB in .NET, understanding its principles and functionalities is crucial. In this guide, we'll walk through how to perform these operations in a .NET environment using EventStoreDB, with code examples to illustrate each step.

Setting Up EventStoreDB

Before diving into CRUD operations, ensure you have EventStoreDB installed and configured. You can download it from the official website and follow the installation instructions provided. Once EventStoreDB is set up and running, you can proceed with integrating it into your .NET application.

Integrating EventStoreDB with .NET

To interact with EventStoreDB in a .NET application, you'll need the EventStoreDB .NET Client, which provides a convenient API for accessing EventStoreDB. Begin by installing the client library via NuGet Package Manager.

dotnet add package EventStore.Client

Next, let's initialize a connection to EventStoreDB.

using EventStore.ClientAPI;

var connectionSettings = ConnectionSettings.Create()
    .KeepReconnecting()
    .SetDefaultUserCredentials(new UserCredentials("username", "password"));

var connection = EventStoreConnection.Create(connectionSettings, new Uri("tcp://localhost:1113"));
connection.ConnectAsync().Wait();

Replace "username" and "password" with your EventStoreDB credentials.

Performing CRUD Operations

1. Creating an Event

using System;
using System.Text;
using EventStore.ClientAPI;

public class Event
{
    public Guid Id { get; set; }
    public string Type { get; set; }
    public string Data { get; set; }
}

// Function to create an event
public void CreateEvent(EventStoreConnection connection, Event @event)
{
    var eventData = Encoding.UTF8.GetBytes(@event.Data);
    var metadata = Encoding.UTF8.GetBytes($"{{\"Type\":\"{@event.Type}\"}}");

    var eventPayload = new EventData(
        Guid.NewGuid(),
        @event.Type,
        true,
        eventData,
        metadata
    );

    connection.AppendToStreamAsync(
        "stream-name",
        ExpectedVersion.Any,
        eventPayload
    ).Wait();
}

2. Reading an Event

// Function to read an event
public void ReadEvent(EventStoreConnection connection, string streamName, int eventNumber)
{
    var slice = connection.ReadStreamEventsForwardAsync(streamName, eventNumber, 1, false).Result;
    var resolvedEvent = slice.Events.FirstOrDefault();

    if (resolvedEvent != null)
    {
        var data = Encoding.UTF8.GetString(resolvedEvent.Event.Data);
        Console.WriteLine($"Event Data: {data}");
    }
    else
    {
        Console.WriteLine("Event not found.");
    }
}

3. Updating an Event (Optional)

EventStoreDB follows an append-only model, making updates to events uncommon. Typically, updates are handled by appending new events that reflect the changes.

4. Deleting an Event (Soft Delete)

// Function to delete an event
public void DeleteEvent(EventStoreConnection connection, string streamName, int eventNumber)
{
    connection.DeleteStreamAsync(streamName, eventNumber, true).Wait();
}

Conclusion

EventStoreDB is a reliable platform for event sourcing and stream-based data storage. It allows developers to execute CRUD operations effectively. Integrating EventStoreDB with .NET applications enables efficient handling of events while maintaining data integrity and reliability. In this article, you will learn the fundamentals of performing CRUD operations using EventStoreDB in a .NET environment.

You can experiment with the examples provided, explore further functionalities offered by EventStoreDB, and adapt them to your specific use cases to leverage the full potential of event sourcing in your applications.