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how to read fields from a data reader

Hello experts,
Can anyone tell me what I'm doing wrong with this data reader? I'm getting a result back when I query the database directly. Browser error is Invalid attempt to read when no data is present.

protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack) 
        {
            Session["uid"] = Request.QueryString["uid"];

            SqlCommand command;
            SqlConnection conn;
            SqlDataReader dr = null;

            string sqlString = @" SELECT first_name + ' ' + last_name full_name FROM people WHERE network_account = @network_account";

            using (conn = new SqlConnection(ConfigurationManager.ConnectionStrings["AdHocReportingConnectionString"].ConnectionString.ToString()))
            {
                using (command = conn.CreateCommand())
                {
                    conn.Open();
                    command.CommandText = sqlString;
                    command.CommandType = CommandType.Text;
                    command.Parameters.AddWithValue("@network_account", Session["uid"].ToString());

                    using (dr = command.ExecuteReader(CommandBehavior.SingleResult))
                    {
                        if (dr.HasRows)
                        {
                            Session["FullName"] = dr["full_name"].ToString();
                        }
                    }
                }
            }
        }

        this.Label1.Text = Session["FullName"].ToString();
     }

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0
dpicco
Asked:
dpicco
  • 2
1 Solution
 
Gary DavisDir Internet SvcsCommented:
After the ExecuteReader, dr has the value, not the row since you are using SingleResult.

Gary Davis
0
 
Gary DavisDir Internet SvcsCommented:
Also, don't use the "using" in this case and also you will not be getting back a datareader.
0
 
Jacques Bourgeois (James Burger)PresidentCommented:
dr = command.ExecuteReader(CommandBehavior.SingleResult);
   if (dr.HasRows)
   {
   dr.Read(); // Retrieves the line
 
   Session["FullName"]=dr.GetString(0);
// or
   Session["FullName"]=dr["FullName"].ToString();
   dr.Close();
}

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Using is useless, since you are not the one who instantiate the DataReader, it is done instide of the SqlCommand object.

Note that there are 2 ways of retrieving a value. The one you were using, and a series that work with individual types (GetString, GetInt32, GetDateTime...).

For such a simple operation, it does not make much difference, but if you were looping through a DataReader that returns many rows, calling Get... is faster because you are dealing with typed data instead of Object data that needs to be converted to the proper type in order to be used.
0
 
dpiccoAuthor Commented:
Thanks.
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