Doctrine 2 (Symfony) Result set mapping with custom field is always null - symfony

Question

I'm performing the following native query in Symfony 2 repository:
$sql = "SELECT f.id, f.title, 'hi' AS custom_field FROM my_feed f";
$em = $this->getEntityManager();
$rsm = new \Doctrine\ORM\Query\ResultSetMapping($em);
$rsm->addEntityResult('MedicalCoreBundle:Feed', 'f');
$rsm->addFieldResult('f', 'id', 'id');
$rsm->addFieldResult('f', 'title', 'title');
$rsm->addFieldResult('f', 'custom_field', 'custom_field');
$query = $em->createNativeQuery($sql, $rsm);
$result = $query->getResult();
I have created the non-mapped property custom_field and its getter and setter getCustomField and setCustomField in the Feed entity.
Mapped fields are hydrated properly but when i add the custom_field RSM i get the following error: Notice: Undefined index: custom_field [...] in symfony\..\AbstractHydrator.php.
Entity code
// non mapped field
private $custom_field;
public function getCustomField()
{
return $this->custom_field;
}
public function setCustomField($number)
{
$this->custom_field = (int) $number;
return $this;
}
What am i doing wrong here ?

Answer 1

You should map custom_field or use addScalarResult instead of addFieldResult
...
$rsm->addScalarResult('custom_field', 'custom_field');
...
result will look like
[
[0=>entity, 'custom_field'=>custom_field value],
[0=>entity, 'custom_field'=>custom_field value],
...
]

Answer 2

Relatvie to your error, you seem to have a F instead of f in custom_Field somewhere.