Hello!

I'm pretty sure that if you haven't an open a database connection when you
want to get something from the database a connection is temporarily open for
you and when you have got the data the connection is closed(returned to the
pool).

This doesn't seem to be right because I get error(no connection is open)
when I  remove this statement
"dataConnection.Open();" from the code below.

Can somebody explain why a connection is not opened ?

class Report
   {
       static void Main(string[] args)
       {
           SqlConnection dataConnection = new SqlConnection();
           try
           {
               dataConnection.ConnectionString = "Integrated
Security=true;" +
                                                 "Initial
Catalog=Northwind;" +
                                                 @"Data
Source=hempc\SQLExpress";
               //dataConnection.Open();
               Console.Write("Please enter a customer ID (% characters);
");
               string customerId = Console.ReadLine();

               SqlCommand dataCommand = new SqlCommand();
               dataCommand.Connection = dataConnection;
               dataCommand.CommandText =
                   "Select OrderID, OrderDate, " +
                   "ShippedDate, ShipName, ShipAddress, ShipCity, " +
                   "ShipCountry ";
               dataCommand.CommandText +=
                   "From Orders " +
                   "where CustomerID='" + customerId + "'";
               Console.WriteLine("About to execute {0}\n\n",
dataCommand.CommandText);

               SqlDataReader dataReader =
dataCommand.ExecuteReader(System.Data.CommandBehavior.CloseConnection);

               while (dataReader.Read())
               {
                   int orderId = dataReader.GetInt32(0);

                   if (dataReader.IsDBNull(2))
                   {
                       Console.WriteLine("Order {0} not yet shipped\n\n",
orderId);
                   }
                   else
                   {
                       DateTime orderDate = dataReader.GetDateTime(1);
                       DateTime shipDate = dataReader.GetDateTime(2);
                       string shipName = dataReader.GetString(3);
                       string shipAddress = dataReader.GetString(4);
                       string shipCity = dataReader.GetString(5);
                       string shipCountry = dataReader.GetString(6);
                       Console.WriteLine(
                           "Order {0}\nPlaced {1}\nShipped {2}\n" +
                           "ToAdress {3}\n{4}\n{5}\n{6}\n\n", orderId,
orderDate,
                           shipDate, shipName, shipAddress, shipCity,
shipCountry);
                   }
               }

               dataReader.Close();
           }
           catch (Exception e)
           {
               Console.WriteLine("Error accessing the database: " +
e.Message);
           }

           finally
           {
               System.Data.ConnectionState state = dataConnection.State;
               dataConnection.Close();
           }
       }
   }
}