Not all identifier properties can be found in the ResultSetMapping: id

$qb1 = $em->createQueryBuilder()->select('c.id');
...
$query1 = $qb1->getQuery();

$doctrinePaginator = new \Doctrine\ORM\Tools\Pagination\Paginator($query1);
$doctrinePaginator->count(); => generate error

But works fine with $query2 !

$qb2 = $em->createQueryBuilder()->select('c');
...
$query2 = $qb2->getQuery();

$doctrinePaginator = new \Doctrine\ORM\Tools\Pagination\Paginator($query2);
$doctrinePaginator->count(); => no error