Symfony 5，表单验证-创建和更新问题/问题的UniqueEntity

use Symfony\Component\Validator\Constraints as Assert;
use Doctrine\ORM\Mapping as ORM;

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

    /**
     * @ORM\Column(type="string", length=180, unique=true)
     * @Assert\NotBlank()
     * @Assert\Email()
     */
    private $email;

    // 其他字段和方法
}

use Symfony\Component\Validator\Validation;
use Symfony\Component\Validator\ConstraintViolationListInterface;

$validator = Validation::createValidator();

$user = new User();
$user->setEmail('existing@example.com');

$violations = $validator->validate($user);

if (count($violations) > 0) {
    foreach ($violations as $violation) {
        echo $violation->getMessage() . "\n";
    }
}

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;

/**
 * @ORM\Entity(repositoryClass=UserRepository::class)
 */
class User
{
    // ...

    /**
     * @Assert\UniqueEntity(fields="email", message="This email is already in use.")
     */
    private $email;

    // ...
}

class UniqueEmailValidator extends ConstraintValidator
{
    public function validate($value, Constraint $constraint)
    {
        $entityManager = $this->context->getEntityManager();
        $repository = $entityManager->getRepository(User::class);

        $existingUser = $repository->findOneByEmail($value);

        if ($existingUser && $existingUser->getId() !== $this->context->getEntity()->getId()) {
            $this->context->buildViolation($constraint->message)
                ->setParameter('{{ value }}', $value)
                ->addViolation();
        }
    }
}