Improve get Team by Id and include Coach and League.

Also add IgnoreCycles to options to prevent recursive problem.

EntityFrameworkCore.API/Controllers/TeamsController.cs

@@ -45,7 +45,16 @@ namespace EntityFrameworkCore.API.Controllers
         [HttpGet("{id}")]
         public async Task<ActionResult<Team>> GetTeam(int id)
         {
-            var team = await _context.Teams.FindAsync(id);
+            if (_context.Teams == null)
+            {
+                return NotFound();
+            }
+
+            // using λ for fun here.
+            var team = await _context.Teams
+                .Include(λ => λ.Coach)
+                .Include(λ => λ.League)
+                .FirstOrDefaultAsync(λ => λ.Id == id);
 
             if (team == null)
             {

EntityFrameworkCore.API/Program.cs

@@ -1,11 +1,16 @@
 using EntityFrameworkCore.Data;
 using Microsoft.EntityFrameworkCore;
+using System.Text.Json.Serialization;
 
 using EntityFrameworkCore.API.Controllers;
 
 var builder = WebApplication.CreateBuilder(args);
 
-builder.Services.AddControllers();
+builder.Services.AddControllers().AddJsonOptions(options =>
+{
+    // IgnoreCycles prevents "System.Text.Json.JsonException: A possible object cycle was detected".
+    options.JsonSerializerOptions.ReferenceHandler = ReferenceHandler.IgnoreCycles;
+});
 
 // Add services to the container.
 // Learn more about configuring OpenAPI at https://aka.ms/aspnet/openapi