It is catching my exception error when I try to do a select student_id student_name from Student and put it in my dropdownlist. I already created the databases called college and tables Student, Course, and StudentCourse and put in fake data.

I store my Connection String in the web.config file.

    <add name="College"
         connectionString="Data Source=localhost\SQLEXPRESS;Initial Catalog=College;
         Integrated Security=true"/>

I also set the read and write permissions for my College.mdf and College_log.LDF using windows Explorer.

Yet I can't get data from my database after I compile successfully and load the page.

Does anyone have a clue what else I may need to do?

protected void Page_Load(object sender, EventArgs e)
private void FillStudentList()

            string connectionString = WebConfigurationManager.ConnectionStrings["College"].ConnectionString;

                // Define the ADO.NET objects for selecting student ID from the datablse
                string selectSQL = "SELECT student_id student_name FROM Student";
                //Define the ADO.NET objects
                SqlConnection con = new SqlConnection(connectionString);

            //    con.ConnectionString = @"Data Source=localhost\SQLEXPRESS;" +
            //        @"User Instance=True;AttachDBFile=|DataDirectory|\College.mdf;" +
            //        "Integrated Security=True";

                SqlCommand cmd = new SqlCommand(selectSQL, con);

                SqlDataReader reader;

                    //Open the connection
                    reader = cmd.ExecuteReader();

                    while (reader.Read())
                        ListItem newItem = new ListItem();
                        newItem.Text = reader["student_id"] + " " + reader["firstname"];
                        newItem.Value = reader["student_id"].ToString();

                    InfoLabel.Text = "<b> Server Version: </b> " + con.ServerVersion;
                    InfoLabel.Text += "<br/><b>Connection Is:</b> " + con.State.ToString();
                catch (Exception err)
                    //Handle an error by displaying the information.
                    InfoLabel.Text = "Error reading the database.";
                    InfoLabel.Text += err.Message;

                // Make sure nothing is currently selected in the list box.
                StudentListDropDownList.SelectedIndex = -1;

Try this

on your desktop create new text file, open it and save As (type: All files) as "conn.udl". then new icon will be created after you save the file.. open it, choose a provider, then type in your server name and enter the log info of your server. then click "test connection" if the connection succeeded, click ok, then re-open the conn.udl as notepad and you will see the working connection string you need.

- well

One thing that I noticed was that you need a comma between each of the columns you wish to retrieve from the table, so change

SELECT student_id student_name FROM Student


SELECT student_id, student_name FROM Student