MySql.Data.MySqlClient.MySqlConnection.Open C# (CSharp) Method

        public override void Open()
        {
            if (State == ConnectionState.Open)
                throw new InvalidOperationException(Resources.ConnectionAlreadyOpen);

            SetState(ConnectionState.Connecting, true);

#if !CF
                // if we are auto enlisting in a current transaction, then we will be
                // treating the connection as pooled
                if (settings.AutoEnlist && Transaction.Current != null)
                {
                    driver = DriverTransactionManager.GetDriverInTransaction(Transaction.Current);
                    if (driver != null &&
                        (driver.IsInActiveUse ||
                        !driver.Settings.EquivalentTo(this.Settings)))
                        throw new NotSupportedException(Resources.MultipleConnectionsInTransactionNotSupported);
                }
#endif

            try
            {
                if (settings.Pooling)
                {
                    MySqlPool pool = MySqlPoolManager.GetPool(settings);
                    if (driver == null)
                        driver = pool.GetConnection();
                    procedureCache = pool.ProcedureCache;
                }
                else
                {
                    if (driver == null)
                        driver = Driver.Create(settings);
                    procedureCache = new ProcedureCache((int) settings.ProcedureCacheSize);
                }
            }
            catch (Exception)
            {
                SetState(ConnectionState.Closed, true);
                throw;
            }

            // if the user is using old syntax, let them know
            if (driver.Settings.UseOldSyntax)
                MySqlTrace.LogWarning(ServerThread,
                    "You are using old syntax that will be removed in future versions");

            SetState(ConnectionState.Open, false);
            driver.Configure(this);
            if (settings.Database != null && settings.Database != String.Empty)
                ChangeDatabase(settings.Database);

            // setup our schema provider
            schemaProvider = new ISSchemaProvider(this);
#if !CF
            perfMonitor = new PerformanceMonitor(this);
#endif

            // if we are opening up inside a current transaction, then autoenlist
            // TODO: control this with a connection string option
#if !MONO && !CF
            if (Transaction.Current != null && settings.AutoEnlist)
                EnlistTransaction(Transaction.Current);
#endif

            hasBeenOpen = true;
			SetState(ConnectionState.Open, true);
		}

        public int InserirPedido(int numCliente, List<Item> pedido)
        {
            int NumPedido = 0;
            int idPedido = 0;
            MySqlConnection conn = new MySqlConnection(connectionString);
            MySqlCommand cmd = new MySqlCommand();

            cmd.Connection = conn;
            conn.Open();

            cmd.CommandText = "Select Max(numero) + 1 from tb_Pedidos";
            NumPedido = int.Parse(cmd.ExecuteScalar().ToString());

            cmd.CommandText = "Insert into tb_Pedidos (numero, id_cliente, data) Values(" + NumPedido + "," + numCliente + ", sysdate()); select Max(id) from tb_Pedidos;";
            idPedido = int.Parse(cmd.ExecuteScalar().ToString());

            foreach (Item item in pedido)
            {
                cmd.CommandText = "insert into tb_items (nome, descricao, preco, quantidade, id_pedido, urlImagem) Values ('" + item.descricao + "', Null,"+ item.preco.ToString().Replace(",",".") + "," + item.quantidade + "," + idPedido + ", Null);";
                cmd.ExecuteNonQuery();
            }

            conn.Close();

            return NumPedido;
        }