using System;
using System.Windows.Forms;
using System.Data.SqlClient; 

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string connetionString = null;
            SqlConnection sqlCnn ;
            SqlCommand sqlCmd ;
            string sql = null;

            connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password";
            sql = "Your SQL Statement Here , like Select * from product";

            sqlCnn = new SqlConnection(connetionString);
            try
            {
                sqlCnn.Open();
                sqlCmd = new SqlCommand(sql, sqlCnn);
                SqlDataReader sqlReader = sqlCmd.ExecuteReader();
                while (sqlReader.Read())
                {
                    MessageBox.Show(sqlReader.GetValue(0) + " - " + sqlReader.GetValue(1) + " - " + sqlReader.GetValue(2));
                }
                sqlReader.Close();
                sqlCmd.Dispose();
                sqlCnn.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Can not open connection ! ");
            }
        }
    }
}