Question

I have two entities: Article and Category. That have a many to many table: article_category.

I can perform this query with no problems in MySQL:

SELECT COUNT(*) cnt, c.id, c.name FROM article_category ac, category c WHERE ac.category_id = c.id GROUP BY c.id ORDER BY cnt DESC

But I am having trouble translating that into a Doctrine2 query. The following returns a class doesn’t exist error, in reference to the article_category table.

[...]
createQuery("SELECT COUNT(*) cnt, c.id, c.name FROM article_category ac, category c WHERE ac.category_id = c.id GROUP BY c.id ORDER BY cnt DESC")
[...]

To specify, my issue is that I don’t know how to access the “category_id” in the many-to-many table.

EDIT

Here is the same query using an inner join (if it makes it easier).

SELECT COUNT(*) cnt, c.id, c.name FROM category c INNER JOIN article_category ac ON c.id = ac.category_id GROUP BY c.id ORDER BY cnt DESC

Answer 1

I was able to figure it out. I used DQL to create the query:

    $qb = $this->getEntityManager()->createQueryBuilder();
    $qb->select('COUNT(c) cnt, c.id, c.name')
    ->from('NatknowEditorBundle:Category', 'c')
    ->innerJoin('c.articles', 'ac')
    ->groupBy('c.id')
    ->orderBy('cnt', 'DESC');

    return $qb->getQuery()->getResult();

I thought I had to specify where the JOIN needed to occur (“… ON c.id = ac.category_id …”). However, since the many-to-many is already mapped by the array collection (in my case “articles”) I have in my “Category” entity, I guess the “ON” is implicit.