doctrine-patterns

Doctrine Patterns (Symfony)

Patterns for working with Doctrine ORM that catch the common pitfalls (N+1, DQL injection, missing indexes, broken migrations). In Doctrine the entity mapping is the source of truth and migrations are generated from it.

1. Entity mapping with attributes

namespace App\Entity;

use App\Repository\SubscriptionRepository;
use Doctrine\DBAL\Types\Types;
use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity(repositoryClass: SubscriptionRepository::class)]
#[ORM\Table(name: 'subscriptions')]
#[ORM\Index(columns: ['user_id', 'status'])]
class Subscription
{
    #[ORM\Id, ORM\GeneratedValue, ORM\Column]
    private ?int $id = null;

    #[ORM\ManyToOne(inversedBy: 'subscriptions')]
    #[ORM\JoinColumn(nullable: false, onDelete: 'CASCADE')]
    private User $user;

    #[ORM\Column(length: 255, unique: true)]
    private string $stripeCustomerId;

    #[ORM\Column(enumType: Status::class)]
    private Status $status;

    #[ORM\Column(type: Types::DECIMAL, precision: 10, scale: 2)]
    private string $amount;

    #[ORM\Column(type: Types::DATETIME_IMMUTABLE)]
    private \DateTimeImmutable $startsAt;
}

• Use enumType: to map a backed enum directly.
• Money/decimals map to Types::DECIMAL (string in PHP — never float).
• Prefer DATETIME_IMMUTABLE over mutable DateTime.
• Declare indexes/unique constraints on the entity — they become migration SQL.

2. Repositories — extend ServiceEntityRepository

namespace App\Repository;

use App\Entity\Subscription;
use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
use Doctrine\Persistence\ManagerRegistry;

/** @extends ServiceEntityRepository<Subscription> */
final class SubscriptionRepository extends ServiceEntityRepository
{
    public function __construct(ManagerRegistry $registry)
    {
        parent::__construct($registry, Subscription::class);
    }

    /** @return Subscription[] */
    public function activeForUser(User $user): array
    {
        return $this->createQueryBuilder('s')
            ->where('s.user = :user')
            ->andWhere('s.status = :status')
            ->setParameter('user', $user)
            ->setParameter('status', Status::Active)
            ->getQuery()
            ->getResult();
    }
}