Doctrine use count() in NativeQuery with ResultSetMapping

Question

i try to use NativeQuery of Doctrine. If i use my SQL ind Phpmyadmin i have the good result. If i use this, my var_dump return an empty array. I don't understand why.

$sql = 'SELECT COUNT(id) as nb FROM app_facture f WHERE SUBSTR(f.datecreate_facture, 1, 4) = 2014 AND SUBSTR(f.numero_facture,1,1) != "E"';
    $rsm = new ResultSetMapping;
    $rsm->addEntityResult('Acme\MyBundle\Entity\Facture', 'f');
    $rsm->addFieldResult('f', 'COUNT(id)', 'nb');

    $query = $this->getEntityManager()->createNativeQuery($sql,$rsm);

    $results = $query->getResult();

    var_dump($results);//return empty array

Thanks

Answer 1

Try

$rsm->addFieldResult('f', 'nb', 'id');

this worked for me.