/**
  * Removes this object from datastore and sets delete attribute.
  *
  * @param      PropelPDO $con
  * @return     void
  * @throws     PropelException
  * @see        BaseObject::setDeleted()
  * @see        BaseObject::isDeleted()
  */
 public function delete(PropelPDO $con = null)
 {
     foreach (sfMixer::getCallables('BaseCourseComment:delete:pre') as $callable) {
         $ret = call_user_func($callable, $this, $con);
         if ($ret) {
             return;
         }
     }
     if ($this->isDeleted()) {
         throw new PropelException("This object has already been deleted.");
     }
     if ($con === null) {
         $con = Propel::getConnection(CourseCommentPeer::DATABASE_NAME, Propel::CONNECTION_WRITE);
     }
     $con->beginTransaction();
     try {
         CourseCommentPeer::doDelete($this, $con);
         $this->setDeleted(true);
         $con->commit();
     } catch (PropelException $e) {
         $con->rollBack();
         throw $e;
     }
     foreach (sfMixer::getCallables('BaseCourseComment:delete:post') as $callable) {
         call_user_func($callable, $this, $con);
     }
 }
 /**
  * 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
     $objects = CoursePeer::doSelect($criteria, $con);
     foreach ($objects as $obj) {
         // delete related CourseComment objects
         $c = new Criteria(CourseCommentPeer::DATABASE_NAME);
         $c->add(CourseCommentPeer::COURSE_ID, $obj->getId());
         $affectedRows += CourseCommentPeer::doDelete($c, $con);
         // delete related CourseDetail objects
         $c = new Criteria(CourseDetailPeer::DATABASE_NAME);
         $c->add(CourseDetailPeer::COURSE_ID, $obj->getId());
         $affectedRows += CourseDetailPeer::doDelete($c, $con);
         // delete related Exam objects
         $c = new Criteria(ExamPeer::DATABASE_NAME);
         $c->add(ExamPeer::COURSE_ID, $obj->getId());
         $affectedRows += ExamPeer::doDelete($c, $con);
     }
     return $affectedRows;
 }