El feed paginado del blog lee los ID de la página actual mediante toIterable(); un lote de grafo limitado carga después autores y etiquetas sin consultas N+1.

Configuración del provider

DoctrineServiceProvider.php

Registra Doctrine como un servicio normal de la aplicación mediante un provider de Lemonade.

<?php

declare(strict_types=1);

namespace App\Providers;

use App\Repository\OrmDemoArticleRepository;
use App\Repository\OrmDemoAuthorRepository;
use App\Repository\OrmDemoTagRepository;
use App\Services\DoctrineEntityManagerFactory;
use App\Services\OrmDemoService;
use Doctrine\ORM\EntityManagerInterface;
use Lemonade\Framework\Container\ContainerInterface;
use Lemonade\Framework\Core\ServiceProviderInterface;

final class DoctrineServiceProvider implements ServiceProviderInterface
{
    public function register(ContainerInterface $container): void
    {
        $container->singleton(DoctrineEntityManagerFactory::class, DoctrineEntityManagerFactory::class);
        $container->singleton(
            EntityManagerInterface::class,
            static fn (ContainerInterface $container): EntityManagerInterface => $container
                ->get(DoctrineEntityManagerFactory::class)
                ->create(),
        );
        $container->set(OrmDemoArticleRepository::class, OrmDemoArticleRepository::class);
        $container->set(OrmDemoTagRepository::class, OrmDemoTagRepository::class);
        $container->set(OrmDemoAuthorRepository::class, OrmDemoAuthorRepository::class);
        $container->singleton(OrmDemoService::class, OrmDemoService::class);
    }
}

Entidad de artículo

OrmDemoArticle.php

Relaciona varios autores y varias etiquetas mediante asociaciones ManyToMany.

<?php

declare(strict_types=1);

namespace App\Entity;

use DateTimeImmutable;
use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;
use InvalidArgumentException;

#[ORM\Entity]
#[ORM\Table(name: 'orm_demo_articles')]
final class OrmDemoArticle
{
    #[ORM\Id]
    #[ORM\GeneratedValue]
    #[ORM\Column(type: 'integer')]
    private ?int $id = null;

    #[ORM\Column(type: 'string', length: 255)]
    private string $title;

    #[ORM\Column(type: 'text')]
    private string $perex;

    /** @var Collection<int, OrmDemoAuthor> */
    #[ORM\ManyToMany(targetEntity: OrmDemoAuthor::class, inversedBy: 'articles', cascade: ['persist'])]
    #[ORM\JoinTable(name: 'orm_demo_article_authors')]
    private Collection $authors;

    #[ORM\Column(type: 'datetime_immutable')]
    private DateTimeImmutable $createdAt;

    /** @var Collection<int, OrmDemoTag> */
    #[ORM\ManyToMany(targetEntity: OrmDemoTag::class, inversedBy: 'articles', cascade: ['persist'])]
    #[ORM\JoinTable(name: 'orm_demo_article_tags')]
    private Collection $tags;

    /**
     * @param non-empty-list<OrmDemoAuthor> $authors
     */
    public function __construct(string $title, string $perex, array $authors, DateTimeImmutable $createdAt)
    {
        if ($authors === []) {
            throw new InvalidArgumentException('An ORM demo article must have at least one author.');
        }

        $this->title = $title;
        $this->perex = $perex;
        $this->createdAt = $createdAt;
        $this->authors = new ArrayCollection();
        $this->tags = new ArrayCollection();

        foreach ($authors as $author) {
            $this->addAuthor($author);
        }
    }

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

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

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

    /** @return list<OrmDemoAuthor> */
    public function authors(): array
    {
        return $this->authors->toArray();
    }

    public function addAuthor(OrmDemoAuthor $author): void
    {
        if (!$this->authors->contains($author)) {
            $this->authors->add($author);
        }
    }

    public function createdAt(): DateTimeImmutable
    {
        return $this->createdAt;
    }

    /** @return Collection<int, OrmDemoTag> */
    public function tags(): Collection
    {
        return $this->tags;
    }

    public function addTag(OrmDemoTag $tag): void
    {
        if (!$this->tags->contains($tag)) {
            $this->tags->add($tag);
        }
    }
}

Entidad de autor

OrmDemoAuthor.php

Los autores son entidades independientes identificadas por un nickname único.

<?php
declare(strict_types=1);

namespace App\Entity;

use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity]
#[ORM\Table(name: 'orm_demo_authors')]
final class OrmDemoAuthor
{
    #[ORM\Id]
    #[ORM\GeneratedValue]
    #[ORM\Column(type: 'integer')]
    private ?int $id = null;

    #[ORM\Column(type: 'string', length: 80, unique: true)]
    private string $nickname;

    /** @var Collection<int, OrmDemoArticle> */
    #[ORM\ManyToMany(targetEntity: OrmDemoArticle::class, mappedBy: 'authors')]
    private Collection $articles;

    public function __construct(string $nickname)
    {
        $this->nickname = $nickname;
        $this->articles = new ArrayCollection();
    }

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

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

Entidad de etiqueta

OrmDemoTag.php

Las etiquetas son entidades compartidas conectadas a los artículos mediante una tabla join.

<?php

declare(strict_types=1);

namespace App\Entity;

use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity]
#[ORM\Table(name: 'orm_demo_tags')]
final class OrmDemoTag
{
    #[ORM\Id]
    #[ORM\GeneratedValue]
    #[ORM\Column(type: 'integer')]
    private ?int $id = null;

    #[ORM\Column(type: 'string', length: 80)]
    private string $name;

    #[ORM\Column(type: 'string', length: 80, unique: true)]
    private string $slug;

    /** @var Collection<int, OrmDemoArticle> */
    #[ORM\ManyToMany(targetEntity: OrmDemoArticle::class, mappedBy: 'tags')]
    private Collection $articles;

    public function __construct(string $name, string $slug)
    {
        $this->name = $name;
        $this->slug = $slug;
        $this->articles = new ArrayCollection();
    }

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

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

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

Repository y paginación

OrmDemoArticleRepository.php

Combina filtros opcionales con paginación a nivel de SQL y evita consultas N+1.

<?php

declare(strict_types=1);

namespace App\Repository;

use App\Entity\OrmDemoArticle;
use App\Services\DoctrineEntityManagerFactory;
use Doctrine\ORM\EntityManagerInterface;

final class OrmDemoArticleRepository
{
    private const GRAPH_BATCH_SIZE = 25;

    public function __construct(private readonly DoctrineEntityManagerFactory $entityManagerFactory)
    {
    }

    public function paginate(int $page, int $perPage, ?string $tag = null, ?string $author = null): OrmDemoArticlePage
    {
        $perPage = max(1, $perPage);
        $count = $this->entityManager()
            ->createQueryBuilder()
            ->select('COUNT(DISTINCT article.id)')
            ->from(OrmDemoArticle::class, 'article');

        if ($tag !== null) {
            $count
                ->innerJoin('article.tags', 'tag')
                ->andWhere('tag.slug = :tag')
                ->setParameter('tag', $tag);
        }

        if ($author !== null) {
            $count
                ->innerJoin('article.authors', 'author')
                ->andWhere('author.nickname = :author')
                ->setParameter('author', $author);
        }

        $total = (int) $count->getQuery()->getSingleScalarResult();
        $page = min(max(1, $page), max(1, (int) ceil($total / $perPage)));

        $idsQuery = $this->entityManager()
            ->createQueryBuilder()
            ->select('DISTINCT article.id AS id')
            ->from(OrmDemoArticle::class, 'article');
        if ($tag !== null) {
            $idsQuery
                ->innerJoin('article.tags', 'tag')
                ->andWhere('tag.slug = :tag')
                ->setParameter('tag', $tag);
        }

        if ($author !== null) {
            $idsQuery
                ->innerJoin('article.authors', 'author')
                ->andWhere('author.nickname = :author')
                ->setParameter('author', $author);
        }

        $idsQuery
            ->orderBy('article.createdAt', 'DESC')
            ->addOrderBy('article.id', 'DESC')
            ->setFirstResult(($page - 1) * $perPage)
            ->setMaxResults($perPage);

        $articles = (function () use ($idsQuery): iterable {
            $entityManager = $this->entityManager();
            $ids = [];

            foreach ($idsQuery->getQuery()->toIterable() as $row) {
                $ids[] = (int) $row['id'];

                if (count($ids) === self::GRAPH_BATCH_SIZE) {
                    yield from $this->fetchGraphBatch($entityManager, $ids);
                    $ids = [];
                    $entityManager->clear();
                }
            }

            if ($ids !== []) {
                yield from $this->fetchGraphBatch($entityManager, $ids);
                $entityManager->clear();
            }
        })();

        return new OrmDemoArticlePage($articles, $total, $page);
    }

    /** @param list<int> $ids @return iterable<OrmDemoArticle> */
    private function fetchGraphBatch(EntityManagerInterface $entityManager, array $ids): iterable
    {
        /** @var list<OrmDemoArticle> $fetched */
        $fetched = $entityManager->createQueryBuilder()
            ->select('article, author, tag')
            ->from(OrmDemoArticle::class, 'article')
            ->leftJoin('article.authors', 'author')
            ->leftJoin('article.tags', 'tag')
            ->where('article.id IN (:ids)')
            ->setParameter('ids', $ids)
            ->getQuery()
            ->getResult();
        $byId = [];

        foreach ($fetched as $article) {
            $byId[$article->id() ?? 0] = $article;
        }

        foreach ($ids as $id) {
            if (isset($byId[$id])) {
                yield $byId[$id];
            }
        }
    }

    public function hasArticles(): bool
    {
        return $this->entityManager()->getRepository(OrmDemoArticle::class)->count([]) > 0;
    }

    public function add(OrmDemoArticle $article): void
    {
        $this->entityManager()->persist($article);
        $this->entityManager()->flush();
    }

    /** @param iterable<OrmDemoArticle> $articles */
    public function addAll(iterable $articles, int $batchSize): void
    {
        $entityManager = $this->entityManager();
        $processed = 0;

        $batchSize = max(1, $batchSize);

        foreach ($articles as $article) {
            $entityManager->persist($article);
            ++$processed;

            if ($processed % $batchSize === 0) {
                $entityManager->flush();
            }
        }

        $entityManager->flush();
    }

    private function entityManager(): EntityManagerInterface
    {
        return $this->entityManagerFactory->create();
    }
}

Cómo funciona el filtrado

Los artículos pueden tener varios autores y varias etiquetas. Ambas asociaciones se mapean en Doctrine ORM como ManyToMany. Al filtrar por autor, Doctrine conecta los artículos mediante la tabla de unión orm_demo_article_authors y los selecciona por author.nickname. Al filtrar por etiqueta, utiliza la tabla de unión orm_demo_article_tags con una condición sobre tag.slug. Los dos filtros se pueden combinar.