A Beginner's Tutorial on Performing Validations in Entity Framework using Partial Methods

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using DataAccessLayer;

namespace EntityFrameworkTestCosnsole
{
    class Program
    {
        static void Main(string[] args)
        {
            string choice = null;
            while (true)
            {
                try
                {
                    // Lets ask the user what he wants to do
                    Console.WriteLine("\nSelect the operation you want to perform");
                    Console.WriteLine("1. Select\n2. Add\n3. Update\n4. Delete\nX. To exit");

                    choice = Console.ReadLine();

                    // If the user want to exit, then let him
                    if (string.Equals(choice, "X", StringComparison.OrdinalIgnoreCase) == true)
                    {
                        break;
                    }

                    // So the user want to perform some operations, let him do it
                    switch (choice)
                    {
                        case "1":
                            using (MotorBikeShopDbEntities db = new MotorBikeShopDbEntities())
                            {
                                List<Bike> bikes = db.Bikes.ToList<Bike>();

                                Console.WriteLine("BikeID | BikeName | Manufacturer | Modelumber");
                                foreach (Bike b in bikes)
                                {
                                    Console.WriteLine(b.BikeID + " | " + b.BikeName + " | " + b.Manufacturer + " | " + b.Modelumber);
                                }
                            }
                            break;

                        case "2":
                            Bike bike = new Bike();
                            Console.WriteLine("Enter Bike Name");
                            bike.BikeName = Console.ReadLine();
                            Console.WriteLine("Enter Bike Manufacturer");
                            bike.Manufacturer = Console.ReadLine();
                            Console.WriteLine("Enter Bike ModelNumber");
                            bike.Modelumber = Console.ReadLine();

                            using (MotorBikeShopDbEntities db = new MotorBikeShopDbEntities())
                            {
                                db.Bikes.AddObject(bike);
                                db.SaveChanges();
                            }

                            Console.WriteLine("A new Bike has been added in the DB");

                            break;
                        case "3":
                            Console.WriteLine("Select ID of Bike to update");
                            int bikeID;
                            if (int.TryParse(Console.ReadLine(), out bikeID) == true)
                            {

                                using (MotorBikeShopDbEntities db = new MotorBikeShopDbEntities())
                                {
                                    Bike bikeToUpdate = db.Bikes.SingleOrDefault<Bike>(p => p.BikeID == bikeID);
                                    if (bikeToUpdate != null)
                                    {
                                        Console.WriteLine("Enter new manufacturer name.");
                                        string newManf = Console.ReadLine();

                                        bikeToUpdate.Manufacturer = newManf;
                                        if (db.SaveChanges() > 0)
                                        {
                                            Console.WriteLine("Updated");
                                        }
                                        else
                                        {
                                            Console.WriteLine("Failed");
                                        }
                                    }
                                    else
                                    {
                                        Console.WriteLine("Bike with this Id not found");
                                    }
                                }
                            }
                            else
                            {
                                Console.WriteLine("Invalid ID");
                            }
                            break;
                        case "4":
                            Console.WriteLine("Select ID of Bike to delete");
                            int bikeId;
                            if (int.TryParse(Console.ReadLine(), out bikeID) == true)
                            {
                                using (MotorBikeShopDbEntities db = new MotorBikeShopDbEntities())
                                {
                                    Bike bikeToDelete = db.Bikes.SingleOrDefault<Bike>(p => p.BikeID == bikeID);
                                    if (bikeToDelete != null)
                                    {
                                        db.DeleteObject(bikeToDelete);

                                        Console.WriteLine("Bike Deleted");
                                    }
                                    else
                                    {
                                        Console.WriteLine("Bike with this Id not found");
                                    }
                                }
                            }
                            else
                            {
                                Console.WriteLine("Invalid ID");
                            }
                            break;
                        default:
                            Console.WriteLine("Invalid Operation");
                            break;
                    }
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                }
            }            
        }
    }
}