using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

                    List<Customer> customers = new List<Customer>()

            {

                new Customer(){ID = Guid.NewGuid(), Age = 23, First = "Joe", Last = "Smith"},

                new Customer(){ID = Guid.NewGuid(), Age = 34, First = "Kevin", Last = "Costner"},

                new Customer(){ID = Guid.NewGuid(), Age = 23, First = "Sally", Last = "Smuthers"},

                new Customer(){ID = Guid.NewGuid(), Age = 56, First = "Mary", Last = "Jane"},

                new Customer(){ID = Guid.NewGuid(), Age = 48, First = "Jane", Last = "Kendall"},

                new Customer(){ID = Guid.NewGuid(), Age = 34, First = "Eve", Last = "Shrimp"},

                new Customer(){ID = Guid.NewGuid(), Age = 31, First = "Donna", Last = "Lynn"},

                new Customer(){ID = Guid.NewGuid(), Age = 21, First = "Sarah", Last = "Spicer"},

            };

​

            List<Order> orders = new List<Order>()

            {

                new Order() {CustomerID = customers[0].ID, Description="Shoes", Price=150.23M, Quantity=1},

                new Order() {CustomerID = customers[0].ID, Description="Phone", Price=130.25M, Quantity=1},

                new Order() {CustomerID = customers[0].ID, Description="Jacket", Price=230.14M, Quantity=1},

​

                new Order() {CustomerID = customers[1].ID, Description="Phone", Price=130.25M, Quantity=1},

                new Order() {CustomerID = customers[1].ID, Description="Jacket", Price=230.14M, Quantity=1},

                new Order() {CustomerID = customers[1].ID, Description="Pants", Price=70.56M, Quantity=1},

                new Order() {CustomerID = customers[2].ID, Description="Jacket", Price=230.14M, Quantity=1},

                new Order() {CustomerID = customers[2].ID, Description="Pants", Price=70.56M, Quantity=1},

                new Order() {CustomerID = customers[2].ID, Description="Shirt", Price=49.99M, Quantity=1},

​

                new Order() {CustomerID = customers[3].ID, Description="Pants", Price=70.56M, Quantity=1},

                new Order() {CustomerID = customers[3].ID, Description="Shirt", Price=49.99M, Quantity=1},

                new Order() {CustomerID = customers[3].ID, Description="Scarf", Price=23.69M, Quantity=1},

​

                new Order() {CustomerID = customers[4].ID, Description="Shirt", Price=49.99M, Quantity=1},

                new Order() {CustomerID = customers[4].ID, Description="Scarf", Price=23.69M, Quantity=1},

                new Order() {CustomerID = customers[4].ID, Description="Car", Price=24200.15M, Quantity=1},

​

                new Order() {CustomerID = customers[5].ID, Description="Scarf", Price=23.69M, Quantity=1},

                new Order() {CustomerID = customers[5].ID, Description="Car", Price=24200.15M, Quantity=1},

                new Order() {CustomerID = customers[5].ID, Description="Computer", Price=650.00M, Quantity=1},

​

                new Order() {CustomerID = customers[6].ID, Description="Car", Price=24200.15M, Quantity=1},

                new Order() {CustomerID = customers[6].ID, Description="Computer", Price=650.00M, Quantity=1},

                new Order() {CustomerID = customers[6].ID, Description="Shoes", Price=150.23M, Quantity=1},

​

                new Order() {CustomerID = customers[7].ID, Description="Computer", Price=650.00M, Quantity=1},

                new Order() {CustomerID = customers[7].ID, Description="Jacket", Price=230.14M, Quantity=1},

                new Order() {CustomerID = customers[7].ID, Description="Pants", Price=70.56M, Quantity=1},

​

            };

​

            IEnumerable<Customer> results = customers.OrderBy(n => n.Last);

            Console.WriteLine("Customers and orders sorted by last name:");

            foreach (Customer cust in results)

            {

                Console.WriteLine("{0} {1}", cust.First, cust.Last);

​

                IEnumerable<Order> result = orders.Where(item => item.CustomerID == cust.ID).OrderBy(m => m.Description);

                Console.WriteLine("Orders:");

                foreach (Order ord in result)

                {

                    Console.WriteLine("{0}, Price: {1}, Quantity: {2}", ord.Description, ord.Price, ord.Quantity);

                }

            }

​

            var q1 = from c in customers

                    join o in orders on c.ID equals o.CustomerID

                    select new { c.First, c.Last, o.Description, o.Price, o.Quantity };

​

            var r = q1.OrderBy(n => n.Last).ThenByDescending(n => n.Description);

​

            double numord = r.Count();

            Console.WriteLine("Total number of orders: {0}", numord);

            //-------------------------------------------------------

            var q2 = from c in customers

                    join o in orders on c.ID equals o.CustomerID

                    where o.Price <= 500

                    select new { c.Last, o.Description };

            double numord2 = q2.Count();

            Console.WriteLine("Number of orders $500 or under: {0}", numord2);

            //--------------------------------------------------------

            var q3 = from c in customers

                     join o in orders on c.ID equals o.CustomerID

                     where o.Price > 500

                     select new { c.Last, o.Description };

            double numord3 = q3.Count();

            Console.WriteLine("Number of orders over $500: {0}", numord3);

​

            decimal numord4 = r.Sum(p => p.Price);

            Console.WriteLine("Total cost for all orders: {0}", numord4);

            //--------------------------------------------------------

            var q4 = from c in customers

                      join o in orders on c.ID equals o.CustomerID

                      where c.Age < 30

                      select new { c.Last, o.Price };

            decimal numord5 = q4.Sum(p => p.Price);

            Console.WriteLine("Total cost for all orders for people 30 or under: {0}", numord5);

            //--------------------------------------------------------

            var q5 = from c in customers

                      join o in orders on c.ID equals o.CustomerID

                      where c.Age >= 30

                      select new { c.Last, o.Price };

            decimal numord6 = q5.Sum(p => p.Price);

            Console.WriteLine("Total cost for all orders for people over 30: {0}", numord6);

            //-------------------------------------------------------

            var ord2 = (from o in orders

                        orderby o.Price

                        select new { o.Description, o.Price }).Distinct().Take(3);

            Console.WriteLine("The 3 least expensive products:");

            foreach(var ord in ord2)

            {

                Console.WriteLine("{0} {1}", ord.Description,ord.Price);

            }

            var ord3 = (from o in orders

                        orderby o.Price descending

                        select new { o.Description, o.Price }).Distinct().Take(3);

            Console.WriteLine("The 3 most expensive products:");

            foreach (var ord in ord3)

            {

                Console.WriteLine("{0} {1}", ord.Description,ord.Price);

            }        

        Console.ReadLine();

       }

    }

​

    public class Customer

    {

        public Guid ID { get; set; }

        public int Age { get; set; }

        public string First { get; set; }

        public string Last { get; set; }

    }

    public class Order

    {

        public Guid CustomerID { get; set; }

        public string Description { get; set; }

        public decimal Price { get; set; }

        public int Quantity { get; set; }

    }