Add update example with no-tracking for coach.

EntityFrameworkCore.Console/Program.cs

@@ -13,6 +13,29 @@ using var context = new DeadBallZoneLeagueDbContext();
 // Rather than raise: "System.InvalidOperationException: Sequence contains no elements."
 // var firstCoach = await context.Coaches.FirstOrDefaultAsync();
 
+async Task UpdateCoach()
+{
+  var coach = await context.Coaches.FindAsync(1);
+  coach.CreatedDate = DateTime.UtcNow;
+  await context.SaveChangesAsync();
+}
+
+async Task UpdateCoachNoTracking()
+{
+  var coach = await context.Coaches
+    .AsNoTracking()
+    .FirstOrDefaultAsync(c => c.Id == 1);
+    // .FindAsync(1); // cannot be used when using no-tracking.
+  coach.CreatedDate = DateTime.UtcNow;
+  Console.WriteLine(context.ChangeTracker.DebugView.LongView);
+  context.Update(coach); // Set Entity state to be updated.
+  // Note that also other fields are considered "updated/modified", such as the CreatedDate.
+  // You can also use:
+  // context.Entry(coach).State = EntityState.Modified;
+  Console.WriteLine(context.ChangeTracker.DebugView.LongView);
+  await context.SaveChangesAsync();
+}
+
 async Task InsertCoach(string name)
 {
   var coach = new Coach { Name = name, CreatedDate = DateTime.UtcNow };

README.md

@@ -102,3 +102,5 @@ The following states are tracked in the `EntityState.State` property:
 * **Unchanged**: no changes to the entity.
 * **Modified**: changes are made to the entity.
 * **Deleted**: the entity is in the database, but is marked for deletion.
+
+The `Find` functions require tracking, instead, use the `First` function, with a lambda for the ID.