def add_or_update(user_id, app_id, value):
        '''
        Editing evaluation.
        '''
        rec = MEvaluation.get_by_signature(user_id, app_id)
        if rec:
            entry = TabEvaluation.update(
                value=value,
            ).where(TabEvaluation.uid == rec.uid)
            entry.execute()
        else:
            TabEvaluation.create(
                uid=tools.get_uuid(),
                user_id=user_id,
                post_id=app_id,
                value=value,
            )
Editing evaluation.