function cleanDBonPurge()
{
$class = new KnowbaseItem_User();
$class->cleanDBonItemDelete($this->getType(), $this->fields['id']);
$class = new Entity_KnowbaseItem();
$class->cleanDBonItemDelete($this->getType(), $this->fields['id']);
$class = new Group_KnowbaseItem();
$class->cleanDBonItemDelete($this->getType(), $this->fields['id']);
$class = new KnowbaseItem_Profile();
$class->cleanDBonItemDelete($this->getType(), $this->fields['id']);
}