Merge pull request #5 from erikshafer/fixes_during_youtube_video_recording

Updates for YouTube video release

Author: erikshafer

README.md

@@ -2,11 +2,13 @@
 
 An application showing the absolute basics of event sourcing with [EventStoreDB (ESDB)](https://www.eventstore.com/).
 
+The accompanying [YouTube video can be found here](https://www.youtube.com/watch?v=SB55-lgK_8I).
 
 ## 💡 Inspiration
 
-Inspired by Nick Chapsas' video about [getting started with Event Sourcing in .NET](https://www.youtube.com/watch?v=n_o-xuuVtmw). This take however uses EventStoreDB as its, well, store of events!
+This effort was inspired by Nick Chapsas' excellent video about [getting started with Event Sourcing in .NET](https://www.youtube.com/watch?v=n_o-xuuVtmw). This version however uses EventStoreDB as its database.
 
+Be sure to check out [Nick's YouTube channel](https://www.youtube.com/@nickchapsas) if you are somehow unfamiliar with his content, as well as his education platform [Dometrain](https://dometrain.com/) where you can level up your software development skills!
 
 ### 📄 Mini-Log / 🤔 Thoughts / 🧠 Brain Dump
 

StudentEnrollment03.Esdb/Program.cs

@@ -91,7 +91,7 @@
 await client.AppendToStreamAsync(
     streamId,
     StreamState.Any,
-    new[] { created, enrolled, enrolled2, enrolled3, emailChanged },
+    new[] { created, enrolled, enrolled2, enrolled3, emailChanged, withdrawn },
     cancellationToken: default
 );
 
@@ -112,23 +112,14 @@ await client.AppendToStreamAsync(
 
 // Okay, taking that StreamResult we're going to make it a List of ResolvedEvents.
 var eventStream = await streamResult.ToListAsync();
-// Get the last event's event number.
-var lastEventNumFromStream = eventStream.Last().Event.EventNumber.ToUInt64();
-
-// Append another event. This time let's make sure no one has appended to (AKA updated) the stream.
-await client.AppendToStreamAsync(
-    streamId,
-    new StreamRevision(lastEventNumFromStream), // checking against expected revision number
-    new[] {  withdrawn },
-    cancellationToken: default
-);
+Console.WriteLine($"Events (total: {eventStream.Count}) from selected stream: ");
 
+// Instantiate our model and then apply state changes from the deserialized events.
 var student = new Student();
-
-Console.WriteLine($"Events (total: {eventStream.Count}) from selected stream: ");
 foreach (var @event in eventStream)
 {
-    switch (DeserializeEvent(@event.Event))
+    var deserializeEvent = DeserializeEvent(@event.Event);
+    switch (deserializeEvent)
     {
         case StudentCreated studentCreated:
             student.Apply(studentCreated);

StudentEnrollment03.Esdb/Student.cs

@@ -18,12 +18,12 @@ public void Apply(Event @event)
             case StudentCreated created:
                 Apply(created);
                 break;
-            case StudentEmailChanged emailChanged:
-                Apply(emailChanged);
-                break;
             case StudentEnrolled enrolled:
                 Apply(enrolled);
                 break;
+            case StudentEmailChanged emailChanged:
+                Apply(emailChanged);
+                break;
             case StudentWithdrew withdrawn:
                 Apply(withdrawn);
                 break;

docker-compose.yml

@@ -1,6 +1,4 @@
-version: "3.4"
-
-services:
+services:
   app01-inmemory:
     build:
       dockerfile: StudentEnrollment01.InMemory/Dockerfile