Datenbank update Daten vorher sichern

Context con,
SQLiteDatabase connection,
SQLiteOpenHelper database

public class DbHandlerHelper extends SQLiteOpenHelper {

    private Context context;

    DbHandlerHelper(Context context) {
        super(context,
                context.getResources().getString(R.string.DATABASE_NAME),
                null,
                Integer.parseInt(context.getResources().getString(R.string.DATABASE_VERSION)));
        this.context = context;
    }


    // Tabellen erzeugen
    @Override
    public void onCreate(SQLiteDatabase db) {
        for(String sql : context.getResources().getStringArray(R.array.create_Db))
            db.execSQL(sql);
    }


    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

        // Alte Daten sichern
        List<DatenA> a = DbMethoden.getAlleDatenA(context, connection, database);
        List<DatenB> b = DbMethoden.getAlleDatenB(context, connection, database);

        db.execSQL("DROP TABLE IF EXISTS " + context.getResources().getString(R.string.TABLE_NAME_A));
        db.execSQL("DROP TABLE IF EXISTS " + context.getResources().getString(R.string.TABLE_NAME_B));
        onCreate(db);

        // Alte Daten wieder einlesen
        for (int i = 0; i <= a.size()-1; i++) {
            DbMethoden.addDatenAToDb(context, connection, database, a.get(i));
        }
        for (int i = 0; i <= b.size()-1; i++) {
            DbMethoden.addDatenBToDb(context, connection, database, b.get(i));
        }
    }

private final Context mContext;
    private DatabaseHelper mDbHelper;
    private SQLiteDatabase mDb;

  public Database open(String pwd) {
        mDb = mDbHelper.getWritableDatabase();
        return this;
    }

Löschen via:
  return mDb.delete(DATABASE_TABLE, where, null) != 0;
Updates via: 
  return mDb.update(DATABASE_TABLE, newValues, where, null) != 0;
Einfügen via:
  return mDb.insert(DATABASE_TABLE, null, initialValues);