Entity Framework Patterns: Select Multiple Entities

using System;
using System.Collections.Generic;
using System.Linq;

namespace TestPatterns
{
	/// <summary>Entry point in the application.</summary>
	class Program
	{
		static void Main(string[] args)
		{
			var idList = GetIDList();

			Console.WriteLine("Selected IDs:");
			foreach (var id in idList)
			{
				Console.WriteLine(id);
			}

			//var orders = SelectingEach.DoSelect(idList);
			//var orders = DoingUnion.DoSelect(idList);
			var orders = DoingWhereIn.DoSelect(idList);
			//var orders = JoiningOnAnotherTable.DoSelect(idList);

			foreach (var o in orders)
			{
				Console.WriteLine("Order:  {0}, Detail Count ({1})", o.OrderID, o.OrderDetail.Count);
			}
		}

		/// <summary>Pick three ids out of the DB.</summary>
		/// <returns></returns>
		private static int[] GetIDList()
		{
			using (var context = new EFDemoEntities())
			{
				var random = new Random();
				var orderIDs = (from o in context.Order
								select o.OrderID).ToArray();
				var randomizedIDs = from id in orderIDs
									orderby random.Next()
									select id;
				var selectedIDs = randomizedIDs.Take(3).ToArray();

				return selectedIDs;
			}
		}
	}
}