我的理论存储库代码不工作，而我是能够访问数据库和读取表数据正常。
我得到这个stacktrace：

EntityManager->getRepository('AppBundle:Person') in src\AppBundle\Controller\PersonViewController.php (line 18) 

  public function indexAction(Request $request) {
         $em = $this->getDoctrine()->getManager();
         $repo = $em->getRepository('AppBundle:Person');
         $persons = $repo->findAll();
         dump($persons);

person实体模型：
Person.php

namespace AppBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * Class Person
 * @Package AppBundle/Entity
 *
 * @ORM\Entity(repositoryClass="AppBundle\Repository\PersonRepository")
 * @ORM\Table(name="[Person]")
 */
class Person {
    /**
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    protected $id;

    /**
     * @ORM\Column(type="string", length=4)
     */
    protected $type;
}

如果这也是必要的，repo代码：
PersonRepository.php

<?php

namespace AppBundle\Repository;

use /** @noinspection PhpUndefinedClassInspection */
    Doctrine\ORM\EntityRepository;

class PersonRepository extends EntityRepository {

    public function create() {
        $entity = new Person();
        $entity->type('WM_B');
        $this->_em->persist($entity);
        $this->_em->flush();
    }
}