Total.aspx.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace ConsumablesPortal
{
    public partial class Total : System.Web.UI.Page
    {

        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["dbconnection"].ConnectionString);
        DataTable dt;
        SqlDataAdapter da;
        protected void Page_Load(object sender, EventArgs e)
        {
            if(!IsPostBack)
            {
                string query = "SELECT * FROM item ";
                dt = new DataTable();
                con.Open();
                da = new SqlDataAdapter(query, this.con);
                da.Fill(dt);
                if(dt.Rows.Count > 0)
                {
                    GridView1.DataSource = dt;
                    GridView1.DataBind();
                }
            }
        }
    }
}