/**
  * This is a method for emulating ON DELETE CASCADE for DBs that don't support this
  * feature (like MySQL or SQLite).
  *
  * This method is not very speedy because it must perform a query first to get
  * the implicated records and then perform the deletes by calling those Peer classes.
  *
  * This method should be used within a transaction if possible.
  *
  * @param      Criteria $criteria
  * @param      PropelPDO $con
  * @return int The number of affected rows (if supported by underlying database driver).
  */
 protected static function doOnDeleteCascade(Criteria $criteria, PropelPDO $con)
 {
     // initialize var to track total num of affected rows
     $affectedRows = 0;
     // first find the objects that are implicated by the $criteria
     $objects = SubscriberPeer::doSelect($criteria, $con);
     foreach ($objects as $obj) {
         // delete related SubscriberGroupMembership objects
         $criteria = new Criteria(SubscriberGroupMembershipPeer::DATABASE_NAME);
         $criteria->add(SubscriberGroupMembershipPeer::SUBSCRIBER_ID, $obj->getId());
         $affectedRows += SubscriberGroupMembershipPeer::doDelete($criteria, $con);
     }
     return $affectedRows;
 }