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;

namespace DBFactory
{
    public partial class Form1 : Form
    {
        private string _MySQLProvider = "MySql.Data.MySqlClient";
        private string _SQLProvider="System.Data.SqlClient";
        private string _OracleProvider ="System.Data.OracleClient";
        private DbProviderFactory _DbProviderFactory;
        private DbConnection _DbConnection = null;
        private DbCommand _DbCommand = null;
        private DbDataAdapter _DbDataAdapter = null;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            try
            {

             string _SQLconnectionstring = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=Test;Data Source=FARHAD-PC";
             string _Oracleconnectionstring = "Data Source=ServiceName;User Id=Username;Password=Password";
             
            _DbProviderFactory = DbProviderFactories.GetFactory(_SQLProvider);
            _DbConnection = _DbProviderFactory.CreateConnection();
            _DbConnection.ConnectionString = _SQLconnectionstring;
            
            _DbConnection.Open();

            if (_DbConnection.State == ConnectionState.Closed)
            {

                MessageBox.Show("اتصال با دیتابیس برقرار نشده است");
            }
            else
            {
                MessageBox.Show("اتصال با دیتابیس با موفقیت بر قرار شده است");
            }
            }
            catch (System.Exception excep)
            {
                MessageBox.Show(excep.Message.ToString());    
            }         

        }
    }
}

 private string _MySQLProvider = "MySql.Data.MySqlClient";
 private string _SQLProvider="System.Data.SqlClient";
 private string _OracleProvider ="System.Data.OracleClient";

_DbProviderFactory = DbProviderFactories.GetFactory("System.Data.SqlClient");

DbCommand 
DbCommandBuilder 
DbConnection 
DbDataAdapter 
DbDataReader 
DbException 
DbParameter 
DbTransaction