QtSql: Capturing Event Notification for Changes in the SQLite DataBase

Question

I have a SQLite database. I am trying to capture events on changes in the database in a Qt program that uses QtSql module, e.g., when a new record is inserted in a table from outside the Qt program. QSqlDatabase class offers a function to subscribe to the notifications, however there is no example in the Qt framework that illustrates how to setup and capture the events. I adopted (after some search on Internet) the following approach, but it is not working and I could not find why.

QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
db.setDatabaseName("file.db");
if (!db.isOpen()) {        
   qFatal("Failed to open database");          
}

if (db.driver()->hasFeature(QSqlDriver::EventNotifications)) {
        db.driver()->subscribeToNotification("IenState"); //"IenState" is table name

        QObject::connect(db.driver(), SIGNAL(notification(const QString &)),
                         this, SLOT(procEvents(const QString &)));
}
else {
        qFatal("Driver does NOT support database event notifications");
}

//slot function
void DbSqlite::procEvents(const QString &name)
{
    qWarning("%s: %s", __func__, qPrintable(name));

    if (name.compare("IenState", Qt::CaseSensitive) == 0) {
       qWarning("%s: from IenState table", __func__);
    }
}

The procEvents slot function is never get called. It looks like the notification signal is never fired from the db.driver. The above code is a snippet from the program based on the Qt Widget Application.