Откат транзакции не работает witH ADO.NET

Question

Я работаю над приложением C# с базой данных Mysql (версия 5.5). Я столкнулся с проблемой, когда мне нужно поймать исключение, возникшее в Mysql. Не имеет значения, пойман ли он в Mysql или dotNet. Проблема в том, что я хочу отменить всю свою предыдущую работу при возникновении ошибки/исключения; будь то MySqlException или пользовательский. И да, я пробовал использовать TransactionScope и MySqlTransaction, но он не отменил мою работу.

public int AddDeviceNew(string IMEI, string Sim, TextBox veh_reg, RadioButtonList veh_icon, RadioButtonList vehicle_type, DropDownList group, DropDownList ddlIsDimts, HiddenField hid_requested_id) 
{ 
    if (conn.State == ConnectionState.Closed) 
    { 
     conn.Open(); 
    } 
     Common_Functions com_Obj = new Common_Functions(); 
     int deviceid; 
     Int64 serviceid; 
     string logText; 
     long Sim_Id; 
     MySqlCommand command = conn.CreateCommand(); 
     MySqlTransaction trans = conn.BeginTransaction(); 

       //command.Connection = conn; 
       //command.CommandText = "SET autocommit = 0"; 
       //command.ExecuteNonQuery(); 

       command.CommandText = "select ffc_status from devices where imei='" + IMEI + "'"; 
       string strdeviceFFCstatus = Convert.ToString(command.ExecuteScalar()); 

       command.CommandText = "select ffc_status from mobile_simcards where mobile_no=" + Sim; 
       string strSIMFFCstatus = Convert.ToString(command.ExecuteScalar()); 

       if (strSIMFFCstatus == "1") 
       { 
        command.CommandText = "delete from mobile_simcards where mobile_no=" + Sim; 
        command.ExecuteNonQuery(); 
       } 

       command.CommandText = "insert into mobile_simcards(network,mobile_no,created,last_updated) values(2,'" + Sim + "',now(),now())"; 
       command.ExecuteNonQuery(); 
       long SimID = command.LastInsertedId; 

       if (strdeviceFFCstatus == "1") 
       { 
        command.CommandText = "delete from devices where imei='" + IMEI + "'"; 
        command.ExecuteNonQuery(); 
       } 
       logText = "--------------------------------------\nDate: " + DateTime.Now.ToString("G") + "\nNotes: \n**Created**\n--------------------------------------\n"; 



       command.CommandText = "insert into devices (sys_user_id,sys_type,sys_simcard,imei,serial_no,fleet_key,heartbeat_type,odometer_offset,hours_offset,`log`,notes) values('3114','15','" + SimID + "','" + IMEI + "','" + IMEI + "','Shggg123',0,'54718','43200','" + logText + "','')"; 
       command.ExecuteNonQuery(); 
       //Sim_Id = command.LastInsertedId; 

       deviceid = Convert.ToInt16(command.LastInsertedId); 

       //----------For MiCar------------- 
       //if (group.SelectedItem.Text == "4551") 
       //{ 
       // for (int i = 1; i <= 30; i++) 
       // { 
       //  command.CommandText = "insert into devicemappingrfid values(" + i + "," + deviceid + ",'',0,1,now())"; 
       //  command.ExecuteNonQuery(); 

       // } 
       //} 
       //-------------------------------- 
       logText = "--------------------------------------\nDate: " + DateTime.Now.ToString("G") + "\nNotes: \n**Created**\n--------------------------------------\n"; 
       command.CommandText = "insert into services(sys_user_id,sys_sage_reference,sys_created,sys_renewal_due,sys_renewal_cost,sys_device_id,veh_reg,veh_icon_1,veh_icon_2,veh_body,veh_chasis,veh_year,veh_seats,veh_avempg,veh_costpermile,veh_wd_auth_start,veh_wd_auth_end,veh_we_auth_start,veh_we_auth_end,veh_sun_auth_start,veh_sun_auth_end,veh_type,`log`,veh_type_name,is_dimts) values(3114,345,now(),'0001-01-01 00:00:00','0.0','" + deviceid + "','" + Regex.Replace(veh_reg.Text, "[^0-9a-zA-Z]+", "") + "','" + veh_icon.SelectedValue + "','','','','','0','0.0','0.0','00:00','00:00','00:00','00:00','00:00','23:59','" + vehicle_type.SelectedValue.ToString() + "','" + logText + "','" + vehicle_type.SelectedItem.Text + "'," + Convert.ToInt16(ddlIsDimts.SelectedValue) + ")"; 
       command.ExecuteNonQuery(); 
       serviceid = Convert.ToInt64(command.LastInsertedId); 

       command.CommandText = "insert into group_services (sys_service_id,sys_group_id,sys_added_date) values(" + serviceid + ",'1998',now())"; 
       command.ExecuteNonQuery(); 
       logText = "--------------------------------------\nDate: " + DateTime.Now.ToString("G") + "\nNotes: \nAdded to Vimal\n--------------------------------------\n"; 
       command.CommandText = "update services set log=CONCAT(log,'" + logText + "') where id='" + serviceid + "'"; 
       command.ExecuteNonQuery(); 

       command.CommandText = "insert into tbl_history_devices (`sys_group_id`,`sys_service_id`) values('1998','" + serviceid + "')"; 
       command.ExecuteNonQuery(); 

       command.CommandText = "select name from `group` where id='" + group.SelectedValue + "'"; 
       string groupName = (string)command.ExecuteScalar(); 

       if (group.SelectedValue != "1998") 
       { 
        command.CommandText = "insert into group_services (sys_service_id,sys_group_id,sys_added_date) values(" + serviceid + "," + group.SelectedValue + ",now())"; 
        command.ExecuteNonQuery(); 
        logText = "--------------------------------------\nDate: " + DateTime.Now.ToString("G") + "\nNotes: \nAdded to " + groupName + "\n--------------------------------------\n"; 
        command.CommandText = "update services set log=CONCAT(log,'" + logText + "') where id='" + serviceid + "'"; 
        command.ExecuteNonQuery(); 

        command.CommandText = "insert into tbl_history_devices (`sys_group_id`,`sys_service_id`) values('" + group.SelectedValue + "','" + serviceid + "')"; 
        command.ExecuteNonQuery(); 

        //-------------------------------------------------------------------------------------------------------------------------------------------- 
        command.CommandText = "insert into device_mapping (device_id,device_imei,sys_simcard,vehID,NewVehID,repair_with_IMEI,reason,device_placed,current_mapped_status) values('" + deviceid + "','" + IMEI + "','" + SimID + "','" + serviceid + "','','','','',1)"; 
        command.ExecuteNonQuery(); 
        //-------------------------------------------------------------------------------------------------------------------------------------------- 


       } 
       command.CommandText = "insert into latest_telemetry (sys_service_id,sys_msg_type,sys_proc_time,sys_proc_host,sys_geofence_id,sys_device_id,gps_time,jny_distance,jny_duration,jny_idle_time,jny_leg_code,jny_device_jny_id,des_movement_id,des_vehicle_id,tel_hours,tel_input_0,tel_input_1,tel_input_2,tel_input_3,tel_temperature,tel_voltage,tel_odometer) values('" + serviceid + "','0',date_add(now(),interval -330 minute),'None','0','" + deviceid + "',now(),'0.0','0','0','0','0','0','0','0',false,false,false,false,'0.0','0.0','0')"; 
       command.ExecuteNonQuery(); 


       if (hid_requested_id.Value != "") 
       { 
        command.CommandText = "update requested_device set device_status=1 where id=" + Convert.ToInt16(com_Obj.Safe(hid_requested_id.Value)) + ""; 
        command.ExecuteNonQuery(); 
       } 
       trans.Commit(); 
       trans.Rollback(); 
       command.Dispose(); 
       return 1; 
      } 

Answer 1

В своем коде вы пытаетесь совершить сделку, а затем откатить его в следующей строке:

trans.Commit(); 
trans.Rollback(); 

Какой смысл в этом? На данный момент откат, безусловно, не будет работать, поскольку транзакция уже совершена.

Я предлагаю обновить код, чтобы следовать структуру, подобную этой:

MySqlCommand command = conn.CreateCommand(); 
MySqlTransaction trans = conn.BeginTransaction(); 
try 
{ 
    // Perform everything that you need, all queries, updates, etc. 
    trans.Commit(); // this line would be executed only if no exceptions were thrown 
} 
catch 
{ 
    // Your error handling code 
    trans.Rollback(); // rollback is only executed when exception is thrown 
}