title: QTableView does not update the data
body: <p>I'm using a QTableView to view some data from sql database.
  the structure is as follows :</p>
  
  <ol>
  <li>QSqlQueryModel</li>
  <li>subclass of QSortFilterProxyModel that's used to filter data through search box</li>
  <li>QTableView and it's model is the proxy model.</li>
  </ol>
  
  <p>Sometimes when I search and the FilterAcceptsRow is called, the view doesn't load the data, surprisingly when I resize the window or click on the header to sort it, the data gets loaded !</p>
  
  <pre><code>bool ProxyModel::filterAcceptsRow(int source_row,
                                    const QModelIndex &amp;source_parent) const
  {
      QModelIndex indName = sourceModel()-&gt;index(source_row,
                                                 7, source_parent);
      QModelIndex indNumber= sourceModel()-&gt;index(source_row,
                                                 6, source_parent);
      QModelIndex indAgency = sourceModel()-&gt;index(source_row,
                                                 0, source_parent);
  
      QModelIndex indStartDate = sourceModel()-&gt;index(source_row,2,source_parent);
      QModelIndex indEndDate = sourceModel()-&gt;index(source_row,1,source_parent);
      if (searchBy == 0) // search by name
      {
          if(sourceModel()-&gt;data(indName).toString().contains(name_))
              return true;
          else
              return false;
      }
      else if( searchBy == 1)  // search by number
      {
          if(sourceModel()-&gt;data(indNumber).toString().toLower().contains(number_.toLower()))
              return true;
          else
              return false;
      }
      else if (searchBy == 2) // search by agency
      {
          return agencyList.indexOf(sourceModel()-&gt;data(indAgency).toString()) == agency_ ;
      }
  
      else if (searchBy == 3) // search By date
      {
          if (sourceModel()-&gt;data(indStartDate).toDate() &gt;= start_ &amp;&amp;
                 sourceModel()-&gt;data(indEndDate).toDate() &lt;= end_)
          return true;
      }
  
      return false;
  }
  </code></pre>
  
  <p>Is there someway to get this working properly ?</p>