Writing SQlite Databse in Qt

I wrote a SQLite database for client server program. but during debug when it comes to line which I star in code it crash and stop debuging. Could you please help me ?thanks

Here is the code:

bool create = !QFile::exists("Message.dat");

if (!myserver.createConnection())
   return 1;

if (create)    ***"Here return false"****

   myserver.insertMessage();

---

void MainWindow::insertMessage()
{
  QSqlQuery query;

  query.prepare("INSERT INTO messages(IPAddress, date, message)"
                        " values(?,?,?)");
 }