/**
  * Find object by primary key using raw SQL to go fast.
  * Bypass doSelect() and the object formatter by using generated code.
  *
  * @param     mixed $key Primary key to use for the query
  * @param     ConnectionInterface $con A connection object
  *
  * @throws \Propel\Runtime\Exception\PropelException
  *
  * @return ChildEngagement A model object, or null if the key is not found
  */
 protected function findPkSimple($key, ConnectionInterface $con)
 {
     $sql = 'SELECT professor_id, subject_id, course_id, school_year_id, created_at, updated_at FROM engagement WHERE subject_id = :p0 AND course_id = :p1 AND school_year_id = :p2';
     try {
         $stmt = $con->prepare($sql);
         $stmt->bindValue(':p0', $key[0], PDO::PARAM_INT);
         $stmt->bindValue(':p1', $key[1], PDO::PARAM_INT);
         $stmt->bindValue(':p2', $key[2], PDO::PARAM_INT);
         $stmt->execute();
     } catch (Exception $e) {
         Propel::log($e->getMessage(), Propel::LOG_ERR);
         throw new PropelException(sprintf('Unable to execute SELECT statement [%s]', $sql), 0, $e);
     }
     $obj = null;
     if ($row = $stmt->fetch(\PDO::FETCH_NUM)) {
         /** @var ChildEngagement $obj */
         $obj = new ChildEngagement();
         $obj->hydrate($row);
         EngagementTableMap::addInstanceToPool($obj, serialize(array((string) $key[0], (string) $key[1], (string) $key[2])));
     }
     $stmt->closeCursor();
     return $obj;
 }