Book Image

Hands-On Domain-Driven Design with .NET Core

By : Alexey Zimarev
Book Image

Hands-On Domain-Driven Design with .NET Core

By: Alexey Zimarev

Overview of this book

Developers across the world are rapidly adopting DDD principles to deliver powerful results when writing software that deals with complex business requirements. This book will guide you in involving business stakeholders when choosing the software you are planning to build for them. By figuring out the temporal nature of behavior-driven domain models, you will be able to build leaner, more agile, and modular systems. You’ll begin by uncovering domain complexity and learn how to capture the behavioral aspects of the domain language. You will then learn about EventStorming and advance to creating a new project in .NET Core 2.1; you’ll also and write some code to transfer your events from sticky notes to C#. The book will show you how to use aggregates to handle commands and produce events. As you progress, you’ll get to grips with Bounded Contexts, Context Map, Event Sourcing, and CQRS. After translating domain models into executable C# code, you will create a frontend for your application using Vue.js. In addition to this, you’ll learn how to refactor your code and cover event versioning and migration essentials. By the end of this DDD book, you will have gained the confidence to implement the DDD approach in your organization and be able to explore new techniques that complement what you’ve learned from the book.
Table of Contents (14 chapters)

Implementing projections

Now it is time to start writing some code. We will use the final code of Chapter 9, CQRS - The Read Side, as the starting point. The final code for this chapter is located in the GitHub repository, in the Chapter11 folder.

We will go step by step and start by implementing one subscription just to see how subscriptions work in the Event Store. Then, we will create a few real read models using both RavenDB and PostgreSQL.

Catch-up subscriptions

In fact, to start making projections, we don't need any databases. I will show you a simple trick that allows you to go on with the initial development quickly, without any thoughts about the database engine that will be used to store read models. Very often...