Add .NET example for web api with Angular client

src/dotnet.md

@@ -40,3 +40,109 @@ dotnet tool list -g
 # Search for tools matching `searchTerm`.
 dotnet tool search searchTerm
 ```
+
+## Add SQLite
+```powershell
+dotnet add package Microsoft.EntityFrameworkCore.Sqlite
+dotnet add package Microsoft.EntityFrameworkCore.Design
+```
+
+### appsettings.json
+```json
+{
+  "ConnectionStrings": {
+    "DefaultConnection": "Data source=./Database/name.db"
+  }
+}
+```
+
+### Data/DataContext.cs
+```csharp
+using API.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace API.Data
+{
+    public class DataContext : DbContext
+    {
+        public DbSet<Thing> Things { get; set; }
+
+        public DataContext(DbContextOptions options) : base(options) { }
+
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            base.OnModelCreating(modelBuilder);
+        }
+    }
+}
+```
+
+### Program.cs
+```csharp
+// Add near the top.
+builder.Services.AddDbContext<DataContext>(options =>
+{
+    options.UseSqlite(builder.Configuration.GetConnectionString("DefaultConnection"));
+});
+
+// Optional: apply migrations on startup. Add after builder.Build().
+using (var scope = app.Services.CreateScope()) {
+    var db = scope.ServiceProvider.GetRequiredService<DataContext>();
+    db.Database.Migrate();
+}
+```
+
+### Create Initial Migration
+```powershell
+dotnet ef migrations add InitialCreate -o Data/Migrations
+dotnet ef database update
+```
+
+## Example: .NET API with Angular Frontend and XUnit Testing
+This example sets up a new .NET webapi project with XUnit testing and an Angular frontend.
+
+```powershell
+# From repo root:
+dotnet new sln
+dotnet new webapi -o API
+dotnet sln add API
+dotnet new gitignore
+git init
+git add .
+git commit -m "Add new .NET webapi project and solution"
+
+# XUnit project.
+dotnet new xunit -o API.Tests
+dotnet add .\API.Tests\API.Tests.csproj reference .\API\API.csproj
+dotnet sln add API.Tests
+git add .
+git commit -m "Add new XUnit project"
+
+# Create Angular application.
+ng new client
+git add .
+git commit -m "Add new Angular application"
+```
+
+## Running via Windows Terminal
+```powershell
+wt -d .\ --title 'Repo Root' `; nt -d .\client\ --title 'ng serve' `; split-pane -H -d .\API\ --title 'dotnet watch run' `; nt -d .\client\src\app\ --title 'ng g ...'`; nt -d .\client\ --title 'ng test' `; split-pane -H -d .\ --title 'dotnet test'
+```
+
+### Alternatively
+```powershell
+# From repo root:
+cd .\API\
+dotnet run
+
+# From repo root:
+dotnet test
+
+# From repo root:
+cd .\client\
+ng serve
+
+# From repo root:
+cd .\client\
+ng test
+```