android sqlite helper class

public class DatabaseHandler extends SQLiteOpenHelper {

// Database Name
    private static final String DATABASE_NAME = "notesManager";

    // PersonNotes table name
    private static final String TABLE_NOTES = "PersonNotes";

    //  Columns names for PersonNotes table
    private static final String KEY_ID = "id";
    private static final String KEY_NOTE = "note";
    private static final String KEY_CREATED_AT = "createdAt";
    private static final String KEY_TO_PERSONID = "toPersonID";
    private static final String KEY_CUR_PERSONID = "cPersonID";

 // PersonSessions table name
    private static final String TABLE_SESSIONS = "PersonSession";

    //  Columns names for PersonSessions table
  //  private static final String KEY_ID = "id";
    private static final String KEY_SESSIONID = "eventId";
    private static final String KEY_TITLE = "title";
    private static final String KEY_SUMMARY = "summary";
    private static final String KEY_TIME = "time";
    private static final String KEY_LOCATION = "location";
  private static final String KEY_DATE = "date";
    private static final String KEY_TIMEINSEC = "timeinsec";
    private static final int version=1;
    public DatabaseHandler(Context context,CursorFactory factory){
    super(context, DATABASE_NAME, factory, version);
    }
 
    public DatabaseHandler(Context context, String name, CursorFactory factory,
int version) {
super(context, DATABASE_NAME, factory, version);

}

@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_NOTES_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_NOTES + " (" + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT  NOT NULL," + KEY_NOTE + " TEXT," + KEY_CUR_PERSONID + " TEXT,"+ KEY_TO_PERSONID + " TEXT,"  + KEY_CREATED_AT + " TEXT" + ")";

String CREATE_SESSIONS_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_SESSIONS + " (" + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT  NOT NULL," + KEY_SESSIONID + " TEXT," + KEY_CUR_PERSONID + " TEXT,"+ KEY_TITLE + " TEXT,"+ KEY_SUMMARY + " TEXT,"+ KEY_TIME + " TEXT," + KEY_LOCATION + " TEXT," + KEY_DATE + " TEXT ," + KEY_TIMEINSEC + " REAL " +")";

       db.execSQL(CREATE_NOTES_TABLE);
       db.execSQL(CREATE_SESSIONS_TABLE);

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NOTES);
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_SESSIONS);
        // Create tables again
        onCreate(db);
}


 
    /** to get the particular person notes*/
    public List<Note> getPersonNotes(String cur_PersonId,String to_PersonId) {
        List<Note> notesList = new ArrayList<Note>();
     
        SQLiteDatabase db = this.getWritableDatabase();
     
        Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_NOTES +
                " where " + KEY_CUR_PERSONID + " = ? AND  " + KEY_TO_PERSONID +  " = ? " , new String[] { cur_PersonId, to_PersonId});


     
        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
            Note note = new Note();
                note.setId(Integer.parseInt(cursor.getString(cursor.getColumnIndex(KEY_ID))));
                note.setNote(cursor.getString(cursor.getColumnIndex(KEY_NOTE)));
                note.setCur_personId(cursor.getString(cursor.getColumnIndex(KEY_CUR_PERSONID)));
                note.setTo_personId(cursor.getString(cursor.getColumnIndex(KEY_TO_PERSONID)));
                note.setCreatedAt(cursor.getString(cursor.getColumnIndex(KEY_CREATED_AT)));
                // Adding contact to list
                notesList.add(note);
            } while (cursor.moveToNext());
        }

        if(cursor != null)
        cursor.close();
        if(db != null)
        db.close();
        return notesList;
    }


    // Deleting single note
    public void deleteNote(Note note) {
        SQLiteDatabase db = this.getWritableDatabase();
        db.delete(TABLE_NOTES, KEY_ID + " = ?",  new String[] { String.valueOf(note.getId()) });

        if(db != null)
        db.close();
    }

    // Getting notes Count
    public int getNotesCount() {
        String countQuery = "SELECT  * FROM " + TABLE_NOTES;
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(countQuery, null);
        cursor.close();
        if(cursor != null)
        cursor.close();
        if(db != null)
        db.close();
        return cursor.getCount();
    }

    // Adding new session
    public long addSession(Session session) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_SESSIONID, session.getEventId());
        values.put(KEY_CUR_PERSONID, session.getCurPersonId());
        values.put(KEY_TITLE, session.getTitle());
        values.put(KEY_SUMMARY, session.getSummary());
        values.put(KEY_TIME, session.getTime());
        values.put(KEY_LOCATION, session.getLocation());
        values.put(KEY_DATE, session.getDate());
       values.put(KEY_TIMEINSEC, session.getTimeinSec());
// System.out.println("TimeIN SEC:"+session.getTimeinSec());
        // Inserting Row
       long row= db.insert(TABLE_SESSIONS, null, values);
        db.close(); // Closing database connection
        return row;
    }
    /** to get the particular person sessions  with multiple where conditions and order by */
    public List<Session> getPersonSeesions(String cur_PersonId,String date) {
        List<Session> sessionsList = new ArrayList<Session>();
     
        SQLiteDatabase db = this.getWritableDatabase();
     
        Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_SESSIONS +
                " where " + KEY_CUR_PERSONID + " = ? AND  " + KEY_DATE +  " = ? ORDER BY "+ KEY_TIMEINSEC , new String[] { cur_PersonId, date});


     
        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
            Session session=new Session();
            session.setId(Integer.parseInt(cursor.getString(cursor.getColumnIndex(KEY_ID))));
            session.setEventId(cursor.getString(cursor.getColumnIndex(KEY_SESSIONID)));
            session.setCurPersonId(cursor.getString(cursor.getColumnIndex(KEY_CUR_PERSONID)));
            session.setTitle(cursor.getString(cursor.getColumnIndex(KEY_TITLE)));
            session.setSummary(cursor.getString(cursor.getColumnIndex(KEY_SUMMARY)));
            session.setTime(cursor.getString(cursor.getColumnIndex(KEY_TIME)));
            session.setLocation(cursor.getString(cursor.getColumnIndex(KEY_LOCATION)));
            session.setDate(cursor.getString(cursor.getColumnIndex(KEY_DATE)));
         
                // Adding Session to list
                sessionsList.add(session);
            } while (cursor.moveToNext());
        }

        if(cursor != null)
        cursor.close();
        if(db != null)
        db.close();
        return sessionsList;
    }

   public int deletePersonSession(String cPid,String eventId){
   
    SQLiteDatabase db = this.getWritableDatabase();
     
     int row = db.delete(TABLE_SESSIONS,  KEY_CUR_PERSONID + " = ? AND  " + KEY_SESSIONID +  " = ?", new String[] { cPid, eventId});

    if(db!=null)
    db.close();
    return row;
    }
}