Doctrine2 DQL Syntax error when ordering by count - doctrine-orm

Question

This is Doctrine Repository function
public function mostReadArticleByUser($userId){
$total = $this->createQueryBuilder('ar')
->select('ar.articleId', 'COUNT(ar)')
->where('ar.authorId = :userId')
->groupBy('ar.articleId')
->orderBy('COUNT(ar)', 'DESC')
->setMaxResults(1)
->setParameter('userId', $userId)
->getQuery()
->getResult();
return $total;
}
which should be equivalent to this query
SELECT article_id, count(id)
FROM profile_article_reads
WHERE author_id = 2
GROUP BY article_id
Order by count(id) DESC
LIMIT 1;
When I execute this code I get error
Error: Expected end of string, got '('
QueryException: SELECT ar.articleId, COUNT(ar) FROM
SciProfileBundle\Entity\ProfileArticleReads ar WHERE ar.authorId =
:userId GROUP BY ar.articleId ORDER BY COUNT(ar) DESC

Answer 1

THe count funtion accept a field, so try with
COUNT(ar.id)
instead of:
COUNT(ar)
Probably for sorting is better using an alias, as example:
public function mostReadArticleByUser($userId){
$total = $this->createQueryBuilder('ar')
->select('ar.articleId', 'COUNT(ar.id) as total')
->where('ar.authorId = :userId')
->groupBy('ar.articleId')
->orderBy('total', 'DESC')
->setMaxResults(1)
->setParameter('userId', $userId)
->getQuery()
->getResult();
return $total;
}
Hope this help