title: How to display drop-down in column of QTableView and filter based on drop-down
body: <p>I am newbie to Qt.  I have to display a chunk of data in a <code>QTableView</code> and filter it column wise. For this I have used <code>QSortFilterProxyModel</code>, but as per requirement each column of the <code>QTableView</code> should have a drop-down list which shows unique values in that column. On selection of any of these values in the drop-down, only the rows having that particular value in the column should be displayed in the <code>QTableView</code> (Like you can do in Excel).</p>
  
  <p>How would I implement this?</p>