交响乐 5；无法访问连接的实体值

Question

在我的添加时间控制器中，我可以看到并访问集合中的变量但是当我尝试在主控制器中访问它们时，我只得到一个空集合，请参见主控制器

我的 ProjectHours 实体

/**
 * Class ProjectHours
 * @ORM\Entity
 */
class ProjectHours
{

    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue
     */
    private $id;


    /**
     * @ORM\Column(type="datetime")
     */
    private $timestamp_start;


    /**
     * @ORM\Column(type="datetime")
     */
    private $timestamp_end;


    /**
     * @ORM\ManyToOne(targetEntity="App\Entity\Project", inversedBy="project_hours")
     * @ORM\JoinColumn(name="project_id", nullable=false, referencedColumnName="id", onDelete="CASCADE")
     */
    private $project;


    /**
     * @ORM\Column(type="dateinterval")
     */
    private $duration;


    public function addProjectHours(ProjectHours $ph)
    {
        $this->project_hours[] = $ph;
    }

    /**
     * @return Collection|ProjectHours[]
     */
    public function getProjectHours()
    {
        return $this->project_hours;
    }

我的项目实体


/**
 * Class Project
 * @ORM\Entity
 */
class Project
{


    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue
     */
    private $id;


    /**
     * @ORM\Column(type="string")
     */
    private $name;


    /**
     * @ORM\ManyToOne(targetEntity="App\Entity\User", inversedBy="projects")
     * @ORM\JoinColumn(name="user_id", nullable=false, referencedColumnName="id")
     */
    private $user;

    /**
     * @ORM\OneToMany(targetEntity="App\Entity\ProjectHours", mappedBy="project", cascade={"persist", "remove"})
     */
    private $project_hours;



    public function addProjectHours(ProjectHours $ph)
    {
        $this->project_hours[] = $ph;
    }

    /**
     * @return Collection|ProjectHours[]
     */
    public function getProjectHours()
    {
        return $this->project_hours;
    }

我的 addHours 控制器

  #[Route('projects/{project}/new', name: 'app_newHours')]
    public function index(Request $request, $project): Response
    {

        $em=$this->getDoctrine()->getManager();
        $project = str_replace('%20', ' ', $project);

        $hour_entry = new ProjectHours();

        $hour_entry->setTimestampStart(new \DateTime('NOW'));
        $hour_entry->setTimestampEnd(new \DateTime('NOW'));

        $pj = $em->getRepository(Project::class)->findOneBy(array('name'=> $project));
        $hour_entry->setProject($pj);

        $form = $this->createForm(AddHoursClassType::class, $hour_entry );
        $form->handleRequest($request);


        if($form->isSubmitted() && $form->isValid())
        {
            $start = $hour_entry->getTimestampStart();
            $end = $hour_entry->getTimestampEnd();

            if($end > $start)
            {
                $interval = $start->diff($end);

                $hour_entry->setDuration($interval);

                $pj->addProjectHours($hour_entry);


                //store to database
                $em->persist($hour_entry);
                $em->persist($pj);
                $em->flush();
                $this->addFlash('success', 'Hours added successfully!');
            }
            else
            {
                $this->addFlash('error', 'End time must be later than start time!');
            }
        }

最后在我的主控制器中

 /**
         * @Route("/projects", name="app_mainscreen")
         */
        public function Main()
        {
            $em = $this->getDoctrine()->getManager();
            $user = $this->getUser();
            $projects = $em->getRepository(Project::class)->findBy(array('user' => $user));
            $hourlist = $this->getHourList($projects, $em);

            dd($projects[0]->getProjectHours());


            return $this->render('home.html.twig', [
                'projectlist' => $projects,
                'hourlist' => $hourlist
            ]);
        }

如果有人能帮助我，将不胜感激！

Answer 1

这是因为在您访问它们（延迟加载）之前，该集合仅保留对实体的引用，如 #initialized: false 所示。由于您在访问集合的任何内容之前正在转储，因此它似乎是空的。此行为旨在在您可能不想访问集合的情况下提高性能，然后不需要获取相关实体。
出于调试目的，您可以通过使用内置方法 toArray:

将集合转换为数组来强制加载集合中的所有项目

dd($projects[0]->getProjectHours()->toArray());

通常，当您循环访问模板中的集合时，应加载单个项目（toArray 不是必需的）。

{% for project in projectlist %}
  Project {{ project.name }} hours:
  <ul>
  {% for hour in project.projectHours %}
    <li>
      Started: {{ hour.timestampStart|date('g:ia D, M jS, Y') }}<br>
      Ended: {{ hour.timestampEnd|date('g:ia D, M jS, Y') }}    
    </li>
  {% endfor %}
  </ul>
{% endfor %}

交响乐 5；无法访问连接的实体值

Symfony5; cant access joined entity values

php

symfony

doctrine

symfony5