อยากทราบวิธี SELECT ข้อมูลเฉพาะ Columnที่ต้องการแล้วมาใส่ใน Datagridview ตามตําแหน่ง Column ที่สรา้งไว้ครับ C#

int row = 0;
            string cmd;
            server = "localhost";
            database = "room_booking";
            uid = "root";
            password = "";
            string connectionString;
            connectionString = "SERVER=" + server + ";" + "DATABASE=" + database + ";" + "UID=" + uid + ";" + "PASSWORD=" + password + ";";
 
            connection = new MySqlConnection(connectionString);

            if (this.OpenConnection() == true)
            {
                cmd = "SELECT a.room_name, b.number_room, c.type_name, a.floor FROM room a ";
                cmd += "LEFT JOIN number_room b ON a.id_room_number = b.id_room_number ";
                cmd += "LEFT JOIN type_room c ON a.id_room_type = c.id_type";
                myCommand = new MySqlCommand(cmd, connection);
                myReader = myCommand.ExecuteReader();

                while(myReader.Read())
                {
                    dataGridView1.Rows.Add();
                    dataGridView1.Rows[row].Cells[0].Value = myReader["room_name"].ToString();
                    dataGridView1.Rows[row].Cells[1].Value = myReader["number_room"].ToString();
                    dataGridView1.Rows[row].Cells[2].Value = myReader["type_name"].ToString();
                    dataGridView1.Rows[row].Cells[3].Value = myReader["floor"].ToString();
                    dataGridView1.Rows[row].Cells[4].Value = "ดูข้อมูล";

                    row += 1;
                }
       
                //close connection
                this.CloseConnection();
            }