/**
  * Selects a collection of Concept objects filtered by history timestamp.
  *
  * @param integer $vocabularyId
  * @param date    $ts The timestamp
  * @return array Array of Concept objects.
  * @throws PropelException Any exceptions caught during processing will be
  *     rethrown wrapped into a PropelException.
  */
 public static function doSelectConceptByHistoryTimestamp($vocabularyId, $ts)
 {
     $c = new Criteria();
     $c->addJoin(ConceptPeer::ID, ConceptPropertyHistoryPeer::CONCEPT_ID);
     $c->setDistinct();
     $c->add(ConceptPeer::VOCABULARY_ID, $vocabularyId);
     $c->add(ConceptPropertyHistoryPeer::CREATED_AT, $ts, Criteria::LESS_EQUAL);
     $c->add(ConceptPropertyHistoryPeer::ACTION, 'deleted', Criteria::NOT_EQUAL);
     $results = ConceptPeer::populateObjects(ConceptPeer::doSelectRS($c));
     return $results;
 }
 /**
  * Method to do selects.
  *
  * @param      Criteria $criteria The Criteria object used to build the SELECT statement.
  * @param      Connection $con
  * @return     array Array of selected Objects
  * @throws     PropelException Any exceptions caught during processing will be
  *		 rethrown wrapped into a PropelException.
  */
 public static function doSelect(Criteria $criteria, $con = null)
 {
     return ConceptPeer::populateObjects(ConceptPeer::doSelectRS($criteria, $con));
 }