Permalinks for Fun and Profit

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Text;

public partial class external : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //we want to generate a full URL, e.g. http://localhost/PermaLinks/?linkid=###
        //this is probably not the best way to do this, but it works ;-)
        string baseUrl = this.Request.Url.AbsoluteUri;
        baseUrl = baseUrl.Replace("/external.aspx", "/?linkid=");
        //generate a table of links using a data reader;
        //we could have used a repeater control instead
        SqlConnection conn = null;
        SqlCommand cmd = null;
        SqlDataReader rdr = null;
        StringBuilder sb = new StringBuilder();
        try
        {
            conn = new SqlConnection(ConfigurationManager.ConnectionStrings["db"].ConnectionString);
            cmd = new SqlCommand("select CampaignLinkId, CampaignLinkDescription from dbo.CampaignLink", conn);
            conn.Open();
            rdr = cmd.ExecuteReader(CommandBehavior.Default);
            sb.Append("<table border='0' align='center' width='90%'>");
            while (rdr.Read())
            {
                //generate a row in the table for each external link
                sb.Append("<tr><td><a href='");
                sb.Append(baseUrl);
                sb.Append(rdr.GetInt32(0));     //link id
                sb.Append("'>");
                sb.Append(rdr.GetString(1));    //campaign link description
                sb.Append("</a></td></tr>");
            }
            sb.Append("</table>");
            this.Literal1.Text = sb.ToString();
        }
        catch(Exception ex)
        {
            //in a real system, only catch SQL errors and report them somewhere...like to CALM ;-)
            this.Literal1.Text = "ERROR: " + ex.Message;
        }
        finally
        {
            if (rdr != null && !rdr.IsClosed)
            {
                rdr.Close();
                rdr.Dispose();
                rdr = null;
            }
            if (conn != null && conn.State != ConnectionState.Closed)
            {
                conn.Close();
                conn.Dispose();
                conn = null;
            }
        }
    }
}