According to Wrox book, the authour has mentioned that using data readers is the most efficient way to fetch data directly. So I try to bind the data to my DropDownList using data readers instead of DataSet, but I could't get the desire result.

My coding is as below:

void Page_Load(object sender, EventArgs e)
    {
        if(!Page.IsPostBack)
        {
            DDList.DataSource = GetEmployeeID();
            DDList.DataBind();
        }
    }

System.Data.SqlClient.SqlDataReader GetEmployeeID()
    {
        string connectToSqlServer = "server=(local);database=Northwind;" +
            "integrated security=true;";

        System.Data.SqlClient.SqlConnection DatabaseConnection =
            new System.Data.SqlClient.SqlConnection(connectToSqlSe rver);

        string queryCommand = "select EmployeeID from Employees order by EmployeeID ASC";

        System.Data.SqlClient.SqlCommand dbCommand =
            new System.Data.SqlClient.SqlCommand();
        dbCommand.CommandText = queryCommand;
        dbCommand.Connection = DatabaseConnection;

        DatabaseConnection.Open();

        System.Data.SqlClient.SqlDataReader myDataReader =
            dbCommand.ExecuteReader(System.Data.CommandBehavio r.CloseConnection);

        return myDataReader;
    }


So, what is the mistake at the coding? One thing is that in Wrox book, it never mention the use of System.Data.SqlClient.SqlDataReader, I add it as a test (I don't know whether this is the syntax that actually exist or otherwise).