Sql Data Reader Example

//Sql Data Reader
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.Sql;
using System.Data.SqlClient;

namespace killercodes_in.SqlDataReader1
{
    public partial class Form1 : Form
    {
        private string _cString1 = "Data Source=(local);Initial Catalog=avyukta;User Id=sa;Password=iamadmin;";
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection sqc = new SqlConnection(_cString1);
            SqlCommand cmd = new SqlCommand("select * from grademstr", sqc);
            SqlDataReader reader;
            try
            {
                sqc.Open();
                sqc.Close();
            }
            catch
            {
            }
            sqc.Open();
            reader = cmd.ExecuteReader();
            while (reader.Read())
            {
                textBox1.Text = reader["Gradeid"].ToString();
                textBox2.Text = reader["GradeCode"].ToString();
                textBox3.Text = reader["GradeDesc"].ToString();
                textBox4.Text = reader["DA_Percent"].ToString();
            }
            reader.Close();
            cmd.Dispose();
            sqc.Close();
        }
    }
}