public function createAssignmentHistory(EiSubjectAssignment $assignment, $is_assignment = true, Doctrine_Connection $conn = null)
{
if ($conn == null) {
$conn = Doctrine_Manager::connection();
}
return $conn->insert($this->getInstance(), array('author_of_assignment' => MyFunction::getGuard()->getId(), 'subject_id' => $assignment->getSubjectId(), 'assign_to' => $assignment->getGuardId(), 'date' => date("Y-m-d H:i:s"), 'is_assignment' => $is_assignment));
}
