projections/creation of read model in C#

EventStoreDB
1

Hi all,

Rather than performing projections in JavaScripts as discussed here:

https://geteventstore.com/blog/20130212/projections-1-theory/index.html

I would like to create a read model (e.g. star schema) in C# during a catchup subscription, hosted inside a windows service. Looking at this:

http://www.c-sharpcorner.com/uploadfile/mspress/chapter-8-complex-event-processing-with-streaminsight/

projections can be achieved using Linq. Could someone please be so kind and point me to C# examples more specific to EventStore? Thanks.

Christian

2

Using a catchup subscription, a callback will fire every time an event arrives. You can do whatever you need to during this callback (or enqueue it for later processing).

James

3

Thanks. Sure I have done this in the past. However, I am looking for more blogs + examples. Any feedback would be appreciated. Thanks.

4

Projac has a nice approach I think when it comes to organising each event’s projection:

https://github.com/yreynhout/Projac/blob/master/src/Recipes/EventStoreIntegration/Usage.cs

5

Thanks this what I was looking for.

https://github.com/yreynhout/Projac/blob/master/Sql.md

Just curious are there any disadvantages of not doing the projections in EventStore using JavaScript but rather using C#?

6

For this type of projection a catchup subscription is the way to go.