@Override
 public long insert(Greeting greeting) {
   SQLiteDatabase db = databaseHelper.getWritableDatabase();
   ContentValues contentValues = new ContentValues();
   contentValues.put(Constants.COLUMN_ID, greeting.getId());
   contentValues.put(Constants.COLUMN_CONTENT, greeting.getContent());
   return db.insert(Constants.DATABASE_TABLE_NAME, null, contentValues);
 }
 @Override
 public int update(Greeting greeting) {
   SQLiteDatabase db = databaseHelper.getWritableDatabase();
   ContentValues contentValues = new ContentValues();
   contentValues.put(Constants.COLUMN_ID, greeting.getId());
   contentValues.put(Constants.COLUMN_CONTENT, greeting.getContent());
   return db.update(
       Constants.DATABASE_TABLE_NAME,
       contentValues,
       Constants.COLUMN_KEY_ID + " = " + greeting.getId(),
       null);
 }