using System;

using System.Linq;

using System.Collections.Generic;

​

public class Product

{

    public string Code { get; set; }

    public string Name { get; set; }

    public string Amount { get; set; }

}

​

​

public class Program

{

    public static void Main()

    {

        var products = new List<Product>()

        {

            new Product() { Code="A1", Name="Vacuum", Amount = "10" },

            new Product() { Code="A2", Name="Iron", Amount = "20" },

            new Product() { Code="A3", Name="Kettle", Amount = "13" },

            new Product() { Code="A2", Name="Microwave", Amount = "11" },

            new Product() { Code="A3", Name="Dryer", Amount = "3" }

        };

​

        var results = products

            .GroupBy

            ( 

                p => p.Code

            )

            .Select

            (

                g => new 

                {

                    Code = g.Key, 

                    Name = string.Join

                    (

                        ",",

                        g.Select( p => p.Name )

                    ), 

                    Amount = string.Join

                    (

                        ",", 

                        g.Select( p => p.Amount.ToString() )

                    )

                }

            );

        foreach (var r in results)

        {

            Console.WriteLine("{0} {1} {2}", r.Code, r.Name, r.Amount);

        }

    }

}