Android : Android SQLiteAssetHelper Can't upgrade read-only database from version 1 to 2:

I want to create an offline dictionary app, that need sometimes to get update and old database will be replaced by new one. It's what I want to do, and I did something like this with SQLiteAssetHelper Library:

Note: SQLiteAssetHelper will copy database from assets folder into app data folder

public class MyDb extends SQLiteAssetHelper {
  private static final String DATABASE_NAME    = "db.sqlite";
  private static final int    DATABASE_VERSION = 1;
  public MyDb(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
  }
}

now i want to update database, after puting new db.sqlite file into assets folder, I have manipulate my codes like this:

public class MyDb extends SQLiteAssetHelper {
  private static final String DATABASE_NAME    = "db.sqlite";
  private static final int    DATABASE_VERSION = 2;
  public MyDb(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
  }
}

but when i compiled and run, it says: Can't upgrade read-only database from version 1 to 2

what is the solution?

by clearing app data, it will works fine...

SORRY FOR MY BAD ENGLISH...