Add example showing difference between directly toList or using IQueryable.

EntityFrameworkCore.Console/Program.cs

@@ -1,4 +1,5 @@
 using EntityFrameworkCore.Data;
+using EntityFrameworkCore.Domain;
 using Microsoft.EntityFrameworkCore;
 
 using var context = new DeadBallZoneLeagueDbContext();
@@ -14,6 +15,50 @@ var teamFour = await context.Teams.SingleOrDefaultAsync(t => t.TeamId == 3);
 // Rather than raise: "System.InvalidOperationException: Sequence contains no elements."
 var coach = await context.Coaches.FirstOrDefaultAsync();
 
+await ListVSIQueryableCall();
+
+async Task ListVSIQueryableCall()
+{
+  Console.WriteLine("Enter '1' for team with Id 1 or enter '2' for teams that contain 'Neo'");
+  var option = Convert.ToInt32(Console.ReadLine());
+  List<Team> teamsAsList = new List<Team>();
+  // After executing ToList, the records are stored in memory.
+  // Operations after that, are also done in memory.
+
+  teamsAsList = await context.Teams.ToListAsync();
+  if (option == 1)
+  {
+    teamsAsList = teamsAsList.Where(t => t.TeamId == 1).ToList();
+  }
+  else if (option == 2)
+  {
+     teamsAsList = teamsAsList.Where(t => t.Name.Contains("Neo")).ToList();
+  }
+  foreach (var team in teamsAsList)
+  {
+    Console.WriteLine(team.Name);
+  }
+
+  // Records stay as IQueryable until the ToList function is called, then the final query is performed.
+  var teamsAsQueryable = context.Teams.AsQueryable();
+  if (option == 1)
+  {
+    teamsAsQueryable = teamsAsQueryable.Where(t => t.TeamId == 1);
+  }
+  else if (option == 2)
+  {
+    teamsAsQueryable = teamsAsQueryable.Where(t => t.Name.Contains("Neo"));
+  }
+
+  // the actual query:
+  teamsAsList = await teamsAsQueryable.ToListAsync();
+
+  foreach (var team in teamsAsList)
+  {
+    Console.WriteLine(team.Name);
+  }
+}
+
 async Task TrackedQuery()
 {
   // EF Core tracks objects that are returned by queries.