using System;

using System.Collections.Generic;

using System.Linq;

using System.Linq.Expressions;

using System.Text;

using System.Threading.Tasks;

​

namespace ConsoleApplication1

{

    public class Program

    {

        public static void Main(string[] args)

        {

            Console.WriteLine("Query 1");           

            var query1 = from p in new Class1<Product>()

                        where p.Id == "100"

                        select p;

​

            Console.WriteLine("Query 2");           

            var query2 = from p in new Class1<Product>()

                        select p;

        }

    }

​

    class Product

    {

        public string Id { get; set; }

        public string Name { get; set; }

    }

​

    class Class1<T>

    {

        public Class1<T> Where(Expression<Func<T, bool>> expression)

        {

            Console.WriteLine("     Where called");

            return this;

        }

        public Class1<T> Select<TResult>(Func<T, TResult> expression)

        {

            Console.WriteLine("     Select called");

            return this;

        }

​

    }

​

}

​