Stupid question for the day,

Just playing around with rewriting my website in .Net,  I want to add a
record to my database table,  in the old ADO, it was simple you could
create a connection and recordset and then rs.AddNew etc... in .Net it
seems they recommend that you  populate a DataTable  then use the
NewRow method

Isnt this bringing back a entire copy of the table (in this case 40,000
users), if so isn't this very inefficient? I know you can run a
insert via a ExecuteNonQuery which is the way I have done it in the
past (usually passing parameters to stored procs)

But I would have thought you should be able to add a row (Datarow) in
this case to a table without returning the entire table when you
connect to it.

Probably being very stupid

heres my code

       try
       {
           // Initializations
           string database = "MyDB.mdb";
           string connectionString =
@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Z:\Web\Database\" +
database;

           //connection
           OleDbConnection cnn = new OleDbConnection();
           cnn.ConnectionString = connectionString;
           cnn.Open();

           OleDbCommand com = cnn.CreateCommand();
           com.CommandText = "Select * from tblUser";

           OleDbDataAdapter da = new OleDbDataAdapter();
           da.SelectCommand = com;

           //DataSet ds = new DataSet();
           //da.Fill(ds, "Users");

           DataTable dt = new DataTable();
           da.Fill(dt);

           //DataRow dr = dt.Rows[0];
           DataRow dr = dt.NewRow();

           dr["FirstName"] = FirstName.ToString();
           dr["Surname"] = Surname.ToString();
           dr["Email"] = Email.ToString();

           dt.Rows.Add(dr);
           da.Update(dt);

           //close up

           cnn.Close();
       }
       catch (OleDbException  ee)
       {
           Console.WriteLine(ee.ToString());
       }