Symfony2 and Doctrine - Error: Invalid PathExpression. Must be a StateFieldPathExpression

Question

I have an entity that looks like this:

/**
 * @Gedmo\\Tree(type=\"nested\")
 * @ORM\\Table(name=\"categories\")
 * @ORM\\Entity()
 */
class Category extends          


        

Answer 1

Solution using createQueryBuilder:

$query->SELECT('pa.id')
        ->from('Category', 'ca');
$query->join('ca.parent', 'pa');

$result = $query->getQuery()->getArrayResult();