Caching reconstructible data
Use cache for values that can be rebuilt safely.
A small blog powered by Doctrine ORM and SQLite.
Doctrine ORM · SQLite · ManyToMany
123 articles
Use cache for values that can be rebuilt safely.
Measure the work that affects a real response.
Namespaced keys make invalidation easier to understand.
A cache should reduce work without hiding correctness problems.
Confirm workers, cache, storage, and configuration before launch.
Use cache for values that can be rebuilt safely. This deterministic field note expands the demo dataset.
Measure the work that affects a real response. This deterministic field note expands the demo dataset.
Namespaced keys make invalidation easier to understand. This deterministic field note expands the demo dataset.
A cache should reduce work without hiding correctness problems. This deterministic field note expands the demo dataset.
Confirm workers, cache, storage, and configuration before launch. This deterministic field note expands the demo dataset.
Use cache for values that can be rebuilt safely. This deterministic field note expands the demo dataset.
Measure the work that affects a real response. This deterministic field note expands the demo dataset.
The paginated blog feed reads current-page IDs through toIterable(); a bounded graph batch then loads authors and tags without N+1 queries.
Registers Doctrine as a regular application service through a Lemonade provider.
<?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);
}
}
Maps multiple authors and multiple tags through ManyToMany associations.
<?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);
}
}
}
Authors are separate entities identified by a unique nickname.
<?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;
}
}
Tags are shared entities connected to articles through a join table.
<?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;
}
}
Combines optional filters with SQL-level pagination and avoids N+1 queries.
<?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();
}
}
Articles can have multiple authors and multiple tags. Both associations are mapped in Doctrine ORM as ManyToMany. When filtering by author, Doctrine connects articles through the join table orm_demo_article_authors and selects them by author.nickname. When filtering by tag, it uses the join table orm_demo_article_tags with a condition on tag.slug. Both filters can be combined.