Abstract Factory Pattern

 Challenge
You are working on an ORM (Object Relational Mapping) framework creation. The
framework could be used in different databases like:
. Sql Server
. Oracle
. MS Access
. OleDb
Based on the database type, you need to create related classes like:
. SqlConnection, SqlCommand when Sql server
. OracleConnection, OracleCommand when Oracle etc.
How to create a family of related objects without implementation of them?
Definition
GoF Definition: "Provide an interface for creating families of related or dependent
objects without specifying their concrete classes"

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing;

namespace AbstractFactory
{
    public interface IControlFactory
    {
        IPanel CreatePanel();
        IButton CreateButton();
    }

    public interface IPanel
    {
        Color BackColor { get ; set; }
    }

    public interface IButton
    {
        Color BackColor { get ; set; }
    }

    public class YellowButton : Button, IButton
    {
        public YellowButton()
        {
            BackColor = Color.Yellow;
        }

        public override Color BackColor
        {
            get;
            set;
        }
    }

    public class YellowPanel : Panel, IPanel
    {
        public YellowPanel()
        {
            BackColor = Color.Yellow;
        }

        public override Color BackColor
        {
            get;
            set;
        }
    }

    public class YellowControlFactory : IControlFactory
    {
        public IPanel CreatePanel()
        {
            return new YellowPanel();
        }

        public IButton CreateButton()
        {
            return new YellowButton();
        }
    }

}


****************************************************
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.Common;
using System.Data.SqlClient;

namespace AbstractFactory
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void MainForm_Load(object sender, EventArgs e)
        {
            SqlClientFactory factory = SqlClientFactory .Instance;
           
            DbConnection connection = factory.CreateConnection();
            DbCommand command = factory.CreateCommand();

            command.Connection = connection;
            command.CommandText = "query here";
            command.ExecuteNonQuery();
        }
    }
}

public abstract class DbProviderFactory
{
    public abstract DbConnection CreateConnection();
    public abstract DbCommand CreateCommand();
}