CQRS: Why, What and How

Please log in to watch this conference skillscast.

Looking back first, they explored how some of the debates in the DDD community about how to implement Eric Evans highlighting ideas led people to the CQRS solution.

They then had a look at some of the problems with aggregates and repositories that CQRS helps with, and how the vision of seperating core from other domains is simplified. They also went over some simple steps to begin moving your layered application in the CQRS direction and give you a taste of what is to come.

Once you have watched this SkillsCast, you should understand the problems that transitioning to CQRS will help you to resolve.

Other topics covered in this SkillsCast are:

• Querying. The easiest part of CQRS to start with is probably querying. From building your view model directly instead of via your domain, through views or viewmodel stores up to dealing with eventual consistency we look at what it takes to put the Q into CQRS. We will talk about the difference between grid and task based approaches to the UI and how working on interaction style eases the burden to seperated queries. We will also look at composite UIs and how they become important when you begin working with scalable architectures. By the end of the session you should have an understanding of different approaches to seperating your queries from your commands and when to use them.

• Commands: With queries under our belt it's time to look at commands. We'll look at how to work with a command bus to decouple your service layer. We will look at using domain events and why they are the missing concept in DDD. We will then talk about event sourcing capture events to allow you to rebuild the state of the system. We will show you how CQRS helps you to scale to meet increasing demand. By the end of this SkillsCast, you should know how to use commands to build a system instead of a more traditional layered architecture.

If this talk inspired you to learn more about CQRS and DDD, you may find the following links useful:

CQRS Questions & Answers on Stackoverflow

Github Repository: Simple CQRS example on Github by Greg Young

Github repository: Deploying the Domain Model Pattern

Upcoming CQRS talks, conferences and meet ups for and by the Skills Matter Community

SkillsCast recordings of talks on CQRS that have been given for and by the Skills Matter community

YOU MAY ALSO LIKE:

• Event Driven Collaboration (SkillsCast recorded in May 2019)
• Live Coding a Roguelike Game (SkillsCast recorded in December 2022)
• Live Coding a Roguelike Game (SkillsCast recorded in December 2022)