Reader get one row at a time

[dot_net_help]

I have bit coneputal problem .

The SqlDataReader can only retrieve one row at a time from the data source and in order for it to get the next record, it has to maintain its connection to the data source..

string sSQL = "SELECT * FROM Products";
string sConnString =
"Server=(local);Database=Northwind;Integrated Security=SSPI;";
using (SqlConnection oCn = new SqlConnection(sConnString))
{
SqlCommand oSelCmd = new SqlCommand(sSQL, oCn);
oSelCmd.CommandType = CommandType.Text;
oCn.Open();
SqlDataReader oDr = oSelCmd.ExecuteReader();
DataGrid1.DataSource = oDr;
DataGrid1.DataBind();
}

if it get one row at a time then how it binds the data to grid if it contain one record at a time