Caching reconstructible data — field note 0053
Use cache for values that can be rebuilt safely. This deterministic field note expands the demo dataset.
Ukážkový blog postavený na Doctrine ORM a SQLite.
Doctrine ORM · SQLite · ManyToMany
296 článkov
Use cache for values that can be rebuilt safely. This deterministic field note expands the demo dataset.
Middleware keeps request policies close to the HTTP boundary. This deterministic field note expands the demo dataset.
Measure the work that affects a real response. This deterministic field note expands the demo dataset.
Do not assume separate database connections share atomic work. This deterministic field note expands the demo dataset.
Listeners can react to domain facts without controller coupling. This deterministic field note expands the demo dataset.
Document ordering when one policy depends on another. This deterministic field note expands the demo dataset.
Pass identifiers instead of serializing a whole object graph. This deterministic field note expands the demo dataset.
Use explicit environment values rather than hidden branches. This deterministic field note expands the demo dataset.
Entity mapping remains an application concern. This deterministic field note expands the demo dataset.
Validate size, type, and lifecycle before accepting a file. This deterministic field note expands the demo dataset.
Fetch the graph needed for one page and avoid N+1 queries. This deterministic field note expands the demo dataset.
Small documented choices make future changes easier. This deterministic field note expands the demo dataset.
Stránkovaný blogový výpis číta ID aktuálnej stránky cez toIterable(); obmedzená graph dávka potom načíta autorov a štítky bez N+1 dotazov.
Registruje Doctrine ako bežnú aplikačnú službu prostredníctvom Lemonade providera.
<?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);
}
}
Mapuje viacerých autorov aj viac štítkov pomocou asociácií 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);
}
}
}
Autori sú samostatné entity určené jedinečným 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;
}
}
Štítky sú zdieľané entity prepojené s článkami cez join tabuľku.
<?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;
}
}
Kombinuje voliteľné filtre so stránkovaním na úrovni SQL a predchádza N+1 dotazom.
<?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();
}
}
Články môžu mať viacerých autorov aj viac štítkov. Obe väzby sú v Doctrine ORM namapované ako ManyToMany. Pri filtrovaní podľa autora Doctrine prepojí články cez spojovaciu tabuľku orm_demo_article_authors a vyberie ich podľa author.nickname. Pri filtrovaní podľa štítku použije spojovaciu tabuľku orm_demo_article_tags a podmienku nad tag.slug. Oba filtre možno kombinovať.