No identifier/primary key specified for Entity "Alura\ORM\Entity\Aluno". Every Entity must have an identifier/primary key.

Aluno.php :

<?php


namespace Alura\ORM\Entity;

use Doctrine\ORM\Mapping as ORM;
use Doctrine\ORM\Mapping\Entity;
use Doctrine\ORM\Mapping\GeneratedValue;
use Doctrine\ORM\Mapping\Id;

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

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

    public function getId(): int
    {
        return $this->id;
    }


    public function getNome(): string
    {
        return $this->nome;
    }

    public function setNome(string $nome): self
    {
        $this->nome = $nome;
        return $this;
    }

}

EntityManagerFactory.php:

<?php


namespace Alura\ORM\Helper;

use Doctrine\ORM\EntityManager;
use Doctrine\ORM\EntityManagerInterface;
use Doctrine\ORM\Tools\Setup;

class EntityManagerFactory
{
    /**
     * @return EntityManagerInterface
     */
    public function getEntityManager():EntityManagerInterface
    {
        $rootDir = __DIR__.'/..';
        $config = Setup::createAnnotationMetadataConfiguration([$rootDir], true);
        $connection = [
            'driver' => 'pdo_sqlite', 'path' => $rootDir . '/var/data/banco.sqlite'
        ];
        return EntityManager::create($connection, $config);
    }

}