Комната: заменить курсор SQLite в Dao?

У меня есть JobIntentService, который повторно устанавливает ожидающие уведомления о тревогах из базы данных SQLite. Он использует запрос и курсор для получения дат уведомлений из 4 разных столбцов в базе данных. Я конвертирую в базу данных Room и не знаю, как преобразовать курсор в метод Dao. Нужно ли мне использовать @Transaction, так как я получаю уведомления из нескольких столбцов в базе данных? Буду признателен за любые идеи или мысли о том, как построить в комнате.

Service

public class Service extends JobIntentService {

static final int JOB_ID = 9;

public static void enqueueWork(Context context, Intent work) {
    enqueueWork(context, RebootService.class, JOB_ID, work);
} 

@Override
protected void onHandleWork(@NonNull Intent intent) {

    AlarmManager alarmManager1;
    Intent brIntent1;
    PendingIntent pendingIntent1;

    SQLiteDB sqLiteDB = SQLiteDB.getInstance(this);
    Calendar cal1 = Calendar.getInstance();

    Cursor cursor = sqLiteDB.resetNotifications(); 

     try {
          if (cursor.getCount() > 0) { 
              cursor.moveToFirst(); 

              int dueDatentimeColumnIndex = cursor.getColumnIndex(ItemContract.ItemEntry.COLUMN_DUEDATENTIME);
              int notifColumnIndex1 = cursor.getColumnIndex(ItemContract.ItemEntry.COLUMN_NOTIFTIME);
              int notif2ColumnIndex2 = cursor.getColumnIndex(ItemContract.ItemEntry.COLUMN_NOTIFTIME2);
              int randColumnIndex1 = cursor.getColumnIndex(ItemContract.ItemEntry.COLUMN_RANDINT);

              while (!cursor.isAfterLast()) {  

                  do {

                      long notifTime1 = cursor.getLong(notifColumnIndex1);
                      int randInt1 = cursor.getInt(randColumnIndex1);
                      cal1.setTime(new Date(notifTime1));

                      // Set up a system AlarmManager to fire a future alarm that sends a Notification
                      // even if the app is in the background or closed.
                      alarmManager1 = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

                      if (cal1.getTimeInMillis() > System.currentTimeMillis()) {                                            
                          brIntent1 = new Intent(this, AlarmReceiver.class);
                       brIntent1.setAction("24Hour");

                       pendingIntent1 = PendingIntent.getBroadcast(this, randInt1, brIntent1,
                                    PendingIntent.FLAG_ONE_SHOT);

                      if (alarmManager1 != null && notifTime1 != -1) {
                          alarmManager1.set(AlarmManager.RTC_WAKEUP, cal1.getTimeInMillis(), pendingIntent1);
                      }
...       
}

SQLiteDB.java

...
public Cursor resetNotifications() {

   SQLiteDatabase db = getReadableDatabase();

   String[] columns = new String[]{
                ItemContract.ItemEntry.COLUMN_NOTIFTIME,
                ItemContract.ItemEntry.COLUMN_NOTIFTIME2,
                ItemContract.ItemEntry.COLUMN_DUEDATENTIME,
                ItemContract.ItemEntry.COLUMN_RANDINT};

        return db.query(
                TABLE_NAME, 
                columns, // The columns to return
                null,      
                null,   
                null,      
                null,       
                null       
        ); 
}

This is the code I came up as a replacement:

public class RebootService extends JobIntentService {

// Unique job ID for this service
static final int JOB_ID = 10000;

// Convenience method for enqueueing work to this service.
public static void enqueueWork(Context context, Intent work) {
    enqueueWork(context, RebootService.class, JOB_ID, work);
}

private QuickcardRepository reposit1;

@Override
protected void onHandleWork(@NonNull Intent intent) {

    reposit1 = new QuickcardRepository(getApplication());

    Bundle extras = intent.getExtras(); // Returns the Intent *that started this Service.*
    if (extras != null) {

        String classname = extras.getString("TAG");

        if (classname != null && classname.equals("bootCompleted")) {

            AlarmManager alarmManager1;
            Intent brIntent1, brIntent2, brIntent3;
            PendingIntent pendingIntent1, pendingIntent2, pendingIntent3;

            Calendar cal1 = Calendar.getInstance();
            Calendar cal2 = Calendar.getInstance();
            Calendar cal3 = Calendar.getInstance();

            List<Quickcard> resetNotificationsList = reposit1.getNotifications();
            // Cycle through the Room database rows to get the Notifications data
            for (Quickcard quickcard: resetNotificationsList) {
                 // Quickcards without a Due date get a Due date in the database of -1.
                 // Therefore, only cycle through and get data for those quickcards that have
                //  a Due data and therefore have Notifications (reminders) where the actual
                //  "Due date" is != -1.
                 if (quickcard.getDuedatentime() != -1) {

                     // Set up the 24-Hour calendar object.
                     long notifTime1 = quickcard.getNotiftime();
                     int randInt1 = quickcard.getRandint();
                     cal1.setTime(new Date(notifTime1));

                     // Set up a system AlarmManager to fire a future alarm that sends a Notification
                     // even if the app is in the background or closed.  Have to add "context" here.
                     alarmManager1 = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

                     // If the stated alarm trigger time is in the past, the alarm will be triggered immediately.
                     // So only set Alarms to fire Notifications for Duedates in the future
                     // (meaning > than the current System time).  Ignore those in the past.
                     if (cal1.getTimeInMillis() > System.currentTimeMillis()) {
                         // For the 24Hour Notifications.
                         // Set up a PendingIntent that will perform broadcast to the BroadcastReceiver.
                         brIntent1 = new Intent(this, AlarmReceiver.class);
                         brIntent1.setAction("24Hour");
                         // Need to use FLAG_ONE_SHOT on the PendingIntent, not FLAG_UPDATE_CURRENT.
                         // A random int is used to be able to set multiple alarms and then to be able to
                         // delete them later (if the user for ex., deletes the quickCards Duedate) using
                         // the same random int.
                         pendingIntent1 = PendingIntent.getBroadcast(this, randInt1, brIntent1,
                                 PendingIntent.FLAG_ONE_SHOT);

                         // Alarms have 3 properties below after "set(...)":
                         // 1) Alarm type:  RTC_WAKEUP type is chosen here to wake the device from sleep.
                         // 2) Trigger time: in this case, 24 hours before the Duedate/Duetime is reached.
                         // 3) Pending Intent:  A future Intent that is sent when the trigger time is reached.
                         int SDK_INT1 = Build.VERSION.SDK_INT;
                         if (SDK_INT1 >= Build.VERSION_CODES.M) {
                             // Wakes up the device in Doze Mode for API Level 23 and higher.
                             // The "... != -1" test only sets up pendingIntents for quickCards that have
                             // a Notification.  quickCards with no Duedate & Duetime are bypassed.
                             if (alarmManager1 != null && notifTime1 != -1) {
                                 alarmManager1.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, cal1.getTimeInMillis(),
                                         pendingIntent1);
                             }
                         } else if (SDK_INT1 >= Build.VERSION_CODES.KITKAT) {
                             // Wakes up the device in Idle Mode for API Level 19 to 22.
                             // The "... != -1" test only sets up pendingIntents for quickCards that have
                             // a Notification.  quickCards with no Duedate & Duetime are bypassed.
                             if (alarmManager1 != null && notifTime1 != -1) {
                                 alarmManager1.setExact(AlarmManager.RTC_WAKEUP, cal1.getTimeInMillis(), pendingIntent1);
                             }
                         } else {
                             // Old APIs Level 18 and below.
                             // The "... != -1" test only sets up pendingIntents for quickCards that have
                             // a Notification.  quickCards with no Duedate & Duetime are bypassed.
                             if (alarmManager1 != null && notifTime1 != -1) {
                                 alarmManager1.set(AlarmManager.RTC_WAKEUP, cal1.getTimeInMillis(), pendingIntent1);
                             }
                         }
                     }