title: What happens if I don't remove database created using QSqlDatabase?
body: <p>The manual describes the correct way to remove database is :</p>
  
  <pre><code>{
  QSqlDatabase db = QSqlDatabase::addDatabase (...);
  QSqlQuery query (db);
  query.exec (...); 
  }
  
  QSqlDatabase::removeDatabase (...);
  </code></pre>
  
  <p>What happens if I close the database but not remove it explicitly?</p>