Get an unmapped field in a native query in Doctrine2 - doctrine-orm

Question

I have a function in Symfony3 with Doctrine2 which is searching for the nearest partner, using latitude and longitude:
public function findNearestPartner($lat,$lng) {
$rsm=new ResultSetMappingBuilder($this->_em);
$rsm->addRootEntityFromClassMetadata('AppBundle\Entity\Partner','p');
$sqlQuery="SELECT p.*, (6371 * acos(cos(radians(:lat)) * cos(radians(p.latitude)) * cos(radians(p.longitude) - radians(:lng)) + sin(radians(:lat)) * sin(radians(p.latitude)))) AS distance
FROM sp_partner p
ORDER BY distance ASC
LIMIT 0,1";
$query=$this->_em
->createNativeQuery($sqlQuery,$rsm)
->setParameter('lat',$lat)
->setParameter('lng',$lng)
;
return $query->getOneOrNullResult();
}
As you see, I get the nearest Partner-Entity back - but there is also the field "distance", which I don't get back (but it would be very useful). Is there any way to get the value of this field?
I read in the docu (http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/native-sql.html), but I can't find anything useful for this case.

Answer 1

You can make it through addScalarResult.
$rsm=new ResultSetMappingBuilder($this->_em);
$rsm->addRootEntityFromClassMetadata('AppBundle\Entity\Partner','p');
$rsm->addScalarResult('distance', 'distance');
the result will be
array:2 [▼
0 => Partner{...},
distance => xxx
]