原则2 - 如何在MongoDB中查询引用的文档

我有两个集合，categories和jobs，jobs集合在categories内部引用。

现在我在CategoryRepository有一个名为getWithActiveJobs()的方法，此方法返回所有引用的作业的类别，这些类别只是未过期和激活。

问题是当我运行此方法时，不会返回任何内容。我是MongoDB的新手，所以请告诉我如何在CategoryRepository内部查询jobs？

这是我的集合（排除了二传手和getter以及其他方法）：

Category.php ：

namespace Ibw'JobeetBundle'Document;
use Ibw'JobeetBundle'Utils'Jobeet;
use Doctrine'ODM'MongoDB'Mapping'Annotations as MongoDB;
/**
 * @MongoDB'Document(collection="categories", repositoryClass="Ibw'JobeetBundle'Repository'CategoryRepository")
 */
class Category
{
    /**
     * @MongoDB'Id(strategy="AUTO")
     */
    protected $id;
    /**
     * @MongoDB'String
     */
    protected $name;
    /**
     * @MongoDB'ReferenceMany(targetDocument="Job")
     */
    protected $jobs = array();
    /**
     * @MongoDB'ReferenceMany(targetDocument="Affiliate")
     */
    protected $affiliates = array();
    /**
     * @MongoDB'String
     */
    protected $slug;
}

Job.php ：

namespace Ibw'JobeetBundle'Document;
use Ibw'JobeetBundle'Utils'Jobeet;
use Symfony'Component'Validator'Constraints as Assert;
use Doctrine'ODM'MongoDB'Mapping'Annotations as MongoDB;
/**
 * @MongoDB'Document(collection="jobs", repositoryClass="Ibw'JobeetBundle'Repository'JobRepository")
 * @Assert'GroupSequence({"Form", "Job"})
 */
class Job
{
    /**
     * @MongoDB'Id(strategy="AUTO")
     */
    protected $id;
    /**
         * @MongoDB'String
         * @Assert'NotBlank(groups={"Form"})
         * @Assert'Choice(callback="getTypeValues", groups={"Form"})
     */
    protected $type;
    /**
         * @MongoDB'String
         * @Assert'NotBlank(groups={"Form"})
     */
    protected $company;
    /**
         * @MongoDB'String
     */
    protected $logo;
        /**
         * @Assert'Image(groups={"Form"})
         */
        protected $file;
    /**
         * @MongoDB'String
         * @Assert'Url(groups={"Form"})
     */
    protected $url;
    /**
         * @MongoDB'String
         * @Assert'NotBlank(groups={"Form"})
     */
    protected $position;
    /**
         * @MongoDB'String
         * @Assert'NotBlank(groups={"Form"})
     */
    protected $location;
    /**
         * @MongoDB'String
         * @Assert'NotBlank(groups={"Form"})
     */
    protected $description;
    /**
         * @MongoDB'String
         * @Assert'NotBlank(groups={"Form"})
     */
    protected $how_to_apply;
    /**
         * @MongoDB'String
         * @Assert'NotBlank()
     */
    protected $token;
    /**
         * @MongoDB'Boolean
     */
    protected $is_public;
    /**
         * @MongoDB'Boolean
     */
    protected $is_activated;
    /**
         * @MongoDB'String
         * @Assert'NotBlank(groups={"Form"})
         * @Assert'Email(groups={"Form"})
     */
    protected $email;
    /**
         * @MongoDB'Date
     */
    protected $expires_at;
    /**
         * @MongoDB'Date
     */
    protected $created_at;
    /**
         * @MongoDB'Date
     */
    protected $updated_at;
    /**
         * @MongoDB'ReferenceOne(targetDocument="Category", cascade={"persist"})
         * @Assert'NotBlank(groups={"Form"})
     */
    protected $category;
}

这是CategoryRepository.php方法：

public function getWithActiveJobs($limit = null)
{
    $qb = $this->createQueryBuilder()
                ->field('jobs')->prime(true)
                ->field('jobs.expires_at')->gt(date('Y-m-d H:i:s', time()))
                ->field('jobs.is_activated')->equals(true)
                ->sort('jobs.expires_at', 'DESC');
    if($limit)
    {
        $qb->limit($limit);
    }
    return $qb->getQuery()->execute();
}

以下是MongoDB categories集合：

> db.categories.find().pretty()
{
    "_id" : ObjectId("527b884610fedf400d8b4589"),
    "name" : "Design",
    "slug" : "design"
}
{
    "_id" : ObjectId("527b884610fedf400d8b458c"),
    "name" : "Administrator",
    "slug" : "administrator"
}
{
    "_id" : ObjectId("527b884610fedf400d8b458a"),
    "jobs" : [
        DBRef("jobs", ObjectId("527b884610fedf400d8b4587"))
    ],
    "name" : "Programming",
    "slug" : "programming"
}
{
    "_id" : ObjectId("527b884610fedf400d8b458b"),
    "jobs" : [
        DBRef("jobs", ObjectId("527b884610fedf400d8b4588"))
    ],
    "name" : "Manager",
    "slug" : "manager"
}