using System;

public class Program

{

    public abstract class Database

    {

        public virtual string Connection { get; set; }

        public virtual string Command { get; set; }

    }

    public class sqlconnection : Database

    {

        public override string Connection

        {

            get { return "SQL Connection"; }

        }

        public override string Command

        {

            get { return "SQL Command"; }

        }

    }

    public class oldConnection : Database

    {

        public override string Connection

        {

            get { return "OLE Connection"; }

        }

        public override string Command

        {

            get { return "OLE Command"; }

        }

    }

    public static void Main()

    {

        int i = 2;

        Database ldb = null;

        switch (i)

        {

            case 1 : 

                ldb = new sqlconnection();

                break;

            case 2 : 

                ldb = new oldConnection();

                break;

        }

        Console.WriteLine(ldb.Connection);

    }

}