XS✔ ◾ EF Core Migrations Rule (#7593)

* Updated rule

* Auto-fix Markdown files

* Fix MD lint errors

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

rules/use-code-migrations/rule.md

@@ -3,22 +3,85 @@ type: rule
 title: Do you know to use code migrations
 uri: use-code-migrations
 authors:
-  - title: Bryden Oliver
-    url: https://www.ssw.com.au/people/bryden-oliver
+  - title: Daniel Mackay
+    url: https://www.ssw.com.au/people/daniel-mackay  
 related: []
 created: 2021-12-13T17:27:38.786Z
 guid: 8284cedd-8eea-4e3b-b04b-451896a615c0
 ---
-::: todo
-TODO: Byrden
-:::
-
+
+Most enterprise applications require a database to store data.  Once you have a database you need a way to manage the schema.
+
+Entity Framework Code First Migrations allow you to update a database schema rather than recreate it from scratch. This is useful when you have a production database that you want to keep, but you want to make changes to the schema.
+
 <!--endintro-->
 
-::: bad
-Bad example - Don't modify database directly
+## Database Schema Management Options
+
+1. Manually modify the database schema (not recommended)
+2. Manually creating SQL scripts (not recommended)
+3. DB Up
+4. Entity Framework Code First Migrations (recommended)
+
+## Configuring Entity Framework Code First Migrations
+
+The following assumes you have an existing project with a database context, entities, and have already installed the EF Core nuget packages.
+
+1. Install EF Core Tools
+
+    ```bash
+    dotnet new tool-manifest
+    dotnet tool install dotnet-ef
+    ```
+
+2. Enable migrations
+
+    ```bash
+    dotnet ef migrations add InitialCreate
+    ```
+
+3. Update database
+
+```bash
+dotnet ef database update
+```
+
+### Using Rider
+
+If you struggle to remember the commands above, Rider has a great UI that makes creating migrations easy.  This is especially useful when you have different projects for both startup and migrations.
+
+::: img-large  
+![Rider - EF Core Migrations](rider-ef-core.png)
+:::
+
+## Executing Entity Framework Code First Migrations
+
+Once you have some migration, you'll then need to decide when these get run.  Naively, developers will often run migrations during program start-up, but this is not recommended.  Doing so can cause issues in a web farm environment, as well as cause unnecessary delays during start-up.  
+
+::: bad  
+
+```csharp
+var dbContext = scope.ServiceProvider.GetRequiredService<EagleEyeDbContext>();
+await dbContext.Database.MigrateAsync();
+```
+
+Figure: Running migrations manually during startup in `program.cs`
 :::
 
+### Entity Framework Migration Bundles
+
+A place to run migrations is during your CICD deployment pipeline.
+
 ::: good
-Good example - modify entities and generate a migration 
-:::
+
+```bash
+dotnet ef migrations bundle --self-contained --force
+.\efbundle.exe --connection {$ENVVARWITHCONNECTION}
+```
+
+Figure: Creating and executing a migration bundle during a CICD pipeline
+:::
+
+::: info  
+if an `appsettings.json` file can be found the connection string can be automatically picked up.
+:::