using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

​

namespace ConsoleApplication1

{

    class Program

    {

        static List<Customers> cust;

        static List<Order> orders;

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        static void Main(string[] args)

        {

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            cust = new List<Customers>();

            orders = new List<Order>();

            FillClasses();

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            int TNumberOfOrder = orders.Count();

            Console.WriteLine("Total number of Orders is : " + TNumberOfOrder.ToString());

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            int TNumberOfOrderUnder500 = orders.Count(x => x.Price <= 500.0M);

            Console.WriteLine("Total number of Orders under $500  is : " + TNumberOfOrderUnder500.ToString());

​

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            int TNumberOfOrderUpper500 = orders.Count(x => x.Price >= 500.0M);

            Console.WriteLine("Total number of Orders upper $500  is : " + TNumberOfOrderUpper500.ToString());

​

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           decimal ThesumPrice = orders.Sum(x => x.Price );

           Console.WriteLine("Total number of Orders upper $500  is : " + ThesumPrice.ToString());

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           var query = (from c in cust

                        from o in orders

                        where c.ID == o.CustomerID && c.Age <= 30

                        select o.Price).Sum();

           Console.WriteLine("The total cost of all orders placed by people aged 30 and under : " + query.ToString());

​

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           var query1 = (from c in cust

                        from o in orders

                        where c.ID == o.CustomerID && c.Age > 30

                        select o.Price).Sum();

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           Console.WriteLine("The total cost of all orders placed by people aged 30 and under : " + query1.ToString());

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           var query2 = (from o in orders

                         orderby o.Price descending

                         select o.Price).Distinct ().Take(3);

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

           foreach (var q in query2)

           {

               Console.WriteLine(q.ToString());

           }

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           var query4 = (from o in orders

                         orderby o.Price 

                         select o.Price).Distinct().Take(3);

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

           foreach (var q in query4)

           {

               Console.WriteLine(q.ToString());

           }

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           var firstquery = from c in cust

                            from o in orders

                            where o.CustomerID == c.ID

                            group by c.Last in groupcust

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

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​

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

           foreach (var q in firstquery)

           {

               Console.WriteLine(q.First + " " + q.Last + "  " + q.o.Description + "      " + q.o.Price + "      " + q.o.Quantity);

          //     for (int i=0; i< 3; i++)

          //     {

         //          Console.WriteLine(q.o.Description + "      " + q.o.Price + "      " + q.o.Quantity);

         //      }

           }

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​

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            Console.ReadLine();

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​

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​

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        }

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​

​

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       public static  void FillClasses()

       {

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​

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            cust = new List<Customers>()

            {

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

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

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

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

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

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

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

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

            };

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            orders = new List<Order>()

            {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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            };

​

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       }

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    }

}

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​

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    class Customers

    {

        public int Age { get; set; }

        public string  First { get; set; }

        public string  Last { get; set; }

        public Guid  ID { get; set; }

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    }

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​

​

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class Order

    {

       // public Guid OrderID { get; set; }

        public string Description { get; set; }

        public decimal  Price { get; set; }

        public int Quantity { get; set; }

        public Guid CustomerID { get; set; }

    }

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