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Derek Comartin

Event Sourcing: Projections with Liquid Projections

Projections are an important yet pretty simple concept when working with event-centric or event sourcing systems. The concept is to build a state from a stream of events. In my previous post, Event Sourcing with SQL Stream Store, I made a pretty basic projection to keep the current account balance. In this post, I’ll use Liquid Projections to accomplish the same task. I recommend checking out my post on SQL Stream Store as I’m using the same example/demo application in this post. Liquid Projections Liquid Projection is a library for building projections. The concept and API are pretty simple, and… Read More »Event Sourcing: Projections with Liquid Projections

Roundup #52: .NET Core and systemd, System.Threading.Channels, screencastR, Configuration Pitfalls

Here are the things that caught my eye recently in .NET.  I’d love to hear what you found most interesting this week.  Let me know in the comments or on Twitter. .NET Core and systemd In preview7 a new package was added to the Microsoft.Extensions set of packages that enables integration with systemd. For the Windows focused, systemd allows similar functionality to Windows Services, there is a post on how to do what we discuss here for Windows Services in this post. This work was contributed by Tom Deseyn from Red Hat. In this post we will create a .NET Core app that runs as a systemd service. The integration… Read More »Roundup #52: .NET Core and systemd, System.Threading.Channels, screencastR, Configuration Pitfalls

Event Sourcing with SQL Stream Store

I’ve known about SQL Stream Store for a bit (I believe when it was called Cedar) but haven’t really looked into it much. The premise is to provide a stream store over SQL. Currently supporting MS SQL Server, PostgreSQL, and MySQL. Meaning it is simply a .NET Library you can use with an SQL implementation. Let’s take a look at how you can implement Event Sourcing with SQL Stream Store. SQL Stream Store Demo Application For this demo/sample, I’m going to create a .NET Core 3 console app. The idea will be to create the stereotypical event-sourcing example of a… Read More »Event Sourcing with SQL Stream Store