title: in Yii's criteria how to get count (*)
body: <p>I'm trying to build a query that has a <code>group by</code> attribute,
  im truing to get the <code>id</code> and the <code>count</code> 
  it keeps telling me that the <code>count (*)</code> is <strong>invalid</strong> column name 
  how could i get the <code>count</code> from the <code>group by</code> query ??</p>