title: QSortFilterProxyModel and filter by integers, booleans
body: <p>I have a <code>QSortFilterProxyModel</code> which is connected to a <code>QSqlQueryModel</code>. In the underlying query there are boolean and integer fields. I would like to filter by these boolean, integers, etc. values. Surprisingly enough (or maybe I'm wrong) <code>QSortFilterProxyModel</code> only filters by strings. This is for instance a "problem" if you want to filter IDs (which are normally integers). If you try for instance to filter an <code>ID=22</code>, you get all the IDs with "22" inside (122, 222, 322, etc.). See <a href="http://qt-project.org/forums/viewthread/5046" rel="nofollow">this link</a> for a non very elegant solution.</p>
  
  <p>But how would you filter by boolean fields? Can someone give some hint? I suppose I have to subclass <code>QSortFilterProxyModel</code>, or is there another method?</p>