Get single row result with Doctrine NativeQuery

You can use $query->getSingleResult(), which will throw an exception if more than one result are found, or if no result is found. (see the related phpdoc here https://github.com/doctrine/doctrine2/blob/master/lib/Doctrine/ORM/AbstractQuery.php#L791)

There's also the less famous $query->getOneOrNullResult() which will throw an exception if more than one result are found, and return null if no result is found. (see the related phpdoc here https://github.com/doctrine/doctrine2/blob/master/lib/Doctrine/ORM/AbstractQuery.php#L752)

Both getSingleResult() and getOneOrNullResult() will throw an exception if there is more than one result. To fix this problem you could add setMaxResults(1) to your query builder.

 $firstSubscriber = $entity->createQueryBuilder()->select('sub')
        ->from("\Application\Entity\Subscriber", 'sub')
        ->where('sub.subscribe=:isSubscribe')
        ->setParameter('isSubscribe', 1)  
        ->setMaxResults(1)
        ->getQuery()
        ->getOneOrNullResult();

->getSingleScalarResult() will return a single value, instead of an array.