title: How to set selected item in QComboBox with QtreeView
body: <p>i have the following code for QComboBox with WtreeView set as combo view</p>
  
  <pre><code>this-&gt;db-&gt;select("SELECT top 10 company, address, phone, id FROM data");
  QTreeView *ptv = new QTreeView(this);
  ptv-&gt;setModel(this-&gt;db-&gt;model);
  ptv-&gt;setColumnHidden(3, true);
  ui-&gt;comboBox-&gt;setModel(this-&gt;db-&gt;model);
  ui-&gt;comboBox-&gt;setView(ptv);
  connect(ui-&gt;comboBox, SIGNAL(activated(int)), this, SLOT(getComboIndex(int)));
  </code></pre>
  
  <p>How can i set selected item or index for column 2 for example. I can set the first column with</p>
  
  <pre><code>ui-&gt;comboBox-&gt;setCurrentIndex(index);
  </code></pre>
  
  <p>but this is not working for other column only for the first.</p>