Doctrine - 查询一对多,单向与来自反向的连接表关联

除非我误读你的问题,否则这看起来很简单:

获取具有特定类别的所有帖子:

$qb = $this->getEntityManager()->createQueryBuilder();

$qb->select('p')
    ->from('SomeBundle:Post', 'p')
    ->join('p.categories', 'c')
    ->where('c.id = :categoryId')
    ->setParameter('categoryId', $categoryId)
    ->getQuery()
    ->getResult();

获取包含各种类别的所有帖子:

$qb = $this->getEntityManager()->createQueryBuilder();

$qb->select('p')
    ->from('SomeBundle:Post', 'p')
    ->join('p.categories', 'c')
    ->where($qb->expr()->in('c.id', ':categoryIds'))
    ->setParameter('categoryIds', $categoryIds) // array of ids
    ->getQuery()
    ->getResult();