You need to use JOIN in Zend ORM
for exmaple
public function getPendingProjects($owner){
$data = $this ->getAdapter()
->select()
->from('campaign' , array('title', 'id'))
->joinLeft('job', 'campaign.id = job.campaign_id', array('count(user_id)'))
->where('campaign.employer_id = ' . (int)$owner . ' AND job.status = 3' );
return $data->query()->fetchAll();
}
taked from here http://zend-frameworks.com/en/articles/zend_db_zend_mysql.html