private function getAnnouncements()
{
$sql = <<<SQL
SELECT journal_announcement.id,journal_announcement.title,journal_announcement.content FROM journal_announcement
SQL;
$rsm = new ResultSetMapping();
$rsm->addScalarResult('id', 'id');
$rsm->addScalarResult('title', 'title');
$rsm->addScalarResult('content', 'content');
$query = $this->em->createNativeQuery($sql, $rsm);
return $query->getResult();
}