binding dropdownlist values to textbox - asp.net

Question

When the user selects an order ID, the rest of the order information is displayed in label(s). Display the following: employee ID, order date, freight, shipped name, and country. This functionality should be implemented using direct data access programmatically.
Edit: code example and additional explanation.
String CS = onfigurationManager.ConnectionStrings["NORTHWNDConnectionString"].ConnectionStr‌​ing;
using (SqlConnection con = new SqlConnection(CS))
{
SqlCommand cmd = new SqlCommand("SELECT OrderID FROM Orders", con);
con.Open();
DropDownList1.DataSource = cmd.ExecuteReader();
DropDownList1.DataTextField = "OrderID";
DropDownList1.DataValueField = "OrderID";
DropDownList1.DataBind();
Label1.Text = Convert.ToString(DropDownList1.SelectedItem.Text);
}
What I want is the other fields which are there in orders table to be displayed when a value is selected in the dropdownlist.

Answer 1

Can you make datatable from the SQL Query result, and then add items to dropdownlist from ID column. When you then select an item from DDL, you show the info where the row from datatable match the selected orderID.
I can write code if you want it isn't cleared what I'm meaning.
UPDATE: with code
var ds = new DataSet();
using (var conn = new SqlConnection(connection))
{
conn.Open();
var command = new SqlCommand("Your SQL Query", conn);
var adapter = new SqlDataAdapter(command);
adapter.Fill(ds);
conn.Close();
} //Now you have a dataset, with one table that matches your query result.
//And now we can use a foreach loop to add every OrderID to dropdownlis
foreach (DataTable table in ds.Tables)
{
foreach (DataRow dr in table.Rows)
{
DDLname.Items.Add(dr[0].ToString());
}
}
//onSelectedValue event
string orderID = DDLname.Text.toString();
Label1.Text = orderID;
foreach (DataTable table in ds.Tables)
{
foreach (DataRow dr in table.Rows)
{
if(dr[0].toString().equals(orderID))
{
Label2.text = dr[1].toString();
Label3.text = dr[2].toString();
etc....
}
}
}

Answer 2

As you labelled your question with ASP.Net, I assume that this is part of an ASP.Net Webforms application. This means that the drop down list will be inside a web page in a browser. Not clear to me is whether you want the label to be displayed immediately when the user select the item, or only after a post to the server.
In the first case, you'll need javascript and probably something like Ajax or JSON to get the data you want to display for the selected item. In the second case, you could add an event handler for the SelectedIndex_Changed Event of your drop down list. This handler should do something like this:
string CS = ConfigurationManager.ConnectionStrings["NORTHWNDConnectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(CS))
{
SqlCommand cmd = new SqlCommand("SELECT OrderID FROM Orders WHERE OrderId = #OrderId", con);
cmd.Parameters.AddWithValue("#OrderId", DropDownList1.SelectedItem.Value);
con.Open();
if (reader.Read())
{
SqlDataReader reader = cmd.ExecuteReader();
Label1.Text = String.Format("Employee ID: {0}, order date: {1}, freight: {2}, shipped name: {3}, and country {4}."
, reader["employeeid"].ToString()
, reader["orderdate"].ToString()
, reader["freight"].ToString()
, reader["shipname"].ToString()
, reader["shipcountry"].ToString());
}
}