Storing all the values of dropdownlist in SQL server

<asp:DropDownList ID="ddlCountry" runat="server" />



c# code  


using System;
using System.Data;
using System.Data.SqlClient;
using System.Web.UI.WebControls;

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindContrydropdown();
}
}
/// <summary>
/// Bind COuntrydropdown
/// </summary>
protected void BindContrydropdown()
{
//conenction path for database
using (SqlConnection con = new SqlConnection("Data Source=maneavinash;Integrated Security=true;Initial Catalog=MySampleDB"))
{
con.Open();
SqlCommand cmd = new SqlCommand("Select UserId,UserName FROM UserInformation", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
ddlCountry.DataSource = ds;
ddlCountry.DataTextField = "UserName";
ddlCountry.DataValueField = "UserId";
ddlCountry.DataBind();
ddlCountry.Items.Insert(0, new ListItem("--Select--", "0"));
con.Close();
}
}