Entities

The default Doctrine ORM connection comes from the .env file: DB_CONNECTION. Further configuration of a new install is not necessary to get started.

Unlike Eloquent, Doctrine ORM is not an active record pattern, but a data-mapper pattern. Every active record model extends a base class that implements all the persistent, database, logic.

Entities are objects with identity. Their identity has a conceptual meaning inside your domain. In an application, each theory has a unique id. You can uniquely identify each theory by that id.

Doctrine entities don’t extend any class, they are just plain PHP classes with properties (and, historically, getters and setters). Historically, the properties are protected or private, so they only can be accessed through getters and setters. However, with property hooks in PHP 8.4, entities composed of global properties only will become the norm.

$scientist = new Scientist();
$scientist->firstName = 'Albert';
$scientist->lastName  = 'Einstein';

$theory = new Theory();
$theory->title = 'Theory of Relativity';
$theory->scientist = $scientist;

$scientist->theories->add($theory);

EntityManager::persist($scientist);
EntityManager::persist($theory);
EntityManager::flush();

In Doctrine ORM, the domain and business logic is completely separated from the persistence logic. This means we have to tell Doctrine how it should map the columns from the database to our Entity class. In this example we are using attributes. Another possibility is XML.

Note

There used to be more ways to define your metadata in Doctrine ORM, but time has shown the only options of Attributes and XML are necessary.

Relations are of type Doctrine\Common\Collections\Collection. When writing an entity, you should assign an empty collection property to a new Doctrine\Common\Collections\ArrayCollection. You can easily add on new relations with ->add(), remove them with ->removeElement() or check if the relation is already defined with ->contains()

The Scientist entity, used in the example above, looks like this when using attributes for the metadata.

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

#[ORM\Entity(repositoryClass: "App\Doctrine\ORM\Repository\ScientistRepository")]
class Scientist
{
    #[ORM\Id]
    #[ORM\Column(type: "integer")]
    #[ORM\GeneratedValue(strategy: "AUTO")]
    private int $id;

    #[ORM\Column(type: "string", nullable: false)]
    private string $firstName;

    #[ORM\Column(type: "string", nullable: false)]
    private string $lastName;

    #[ORM\OneToMany(targetEntity: Theory::class, mappedBy: "scientist")]
    private Collection $theories;

    public function __construct()
    {
        $this->theories = new ArrayCollection();
    }
}

The related Theory entity looks like this:

use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity(repositoryClass: "App\Doctrine\ORM\Repository\TheoryRepository")]
class Theory
{
    #[ORM\Id]
    #[ORM\Column(type: "integer")]
    #[ORM\GeneratedValue(strategy: "AUTO")]
    private int $id;

    #[ORM\Column(type: "string", nullable: false)]
    private string $title;

    #[ORM\ManyToOne(targetEntity: Scientist::class, inversedBy: "theories")]
    #[ORM\JoinColumn(name: "scientist_id", referencedColumnName: "id", nullable: false)]
    private Scientist $scientist;
}

Metadata

Because Doctrine entities do not extend any smart ancestor class, we have to tell Doctrine how to map the data from the database into the entity. There are multiple ways of doing this.

Attributes

Attributes mean that you will use attributes to indicate the column mappings.

namespace App\Doctrine\ORM\Entity;

 use Doctrine\ORM\Mapping as ORM;

 #[ORM\Entity]
 #[ORM\Table(name: "articles")]
 class Article
 {
     #[ORM\Id]
     #[ORM\Column(type: "integer")]
     #[ORM\GeneratedValue(strategy: "AUTO")]
     private $id;

     #[ORM\Column(type: "string", nullable: false)]
     private $title;
 }

More about the attributes driver: https://www.doctrine-project.org/projects/doctrine-orm/en/2.11/reference/attributes-reference.html

XML

Another option are XML mappings. It’s better to change the metadata paths to something like config_path('doctrine_orm_metadata') for your xml files.

App.Doctrine.ORM.Entity.Article.dcm.xml

<?xml version="1.0"?>
<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping https://www.doctrine-project.org/schemas/orm/doctrine-mapping.xsd">
  <entity name="App\Doctrine\ORM\Entity\Article" table="articles">
    <id name="id" type="integer">
      <generator strategy="AUTO"/>
    </id>
    <field name="title" type="string" nullable="false"/>
  </entity>
</doctrine-mapping>

More information about XML mappings: https://www.doctrine-project.org/projects/doctrine-orm/en/2.6/reference/xml-mapping.html

---

This is documentation for laravel-doctrine/orm. Please add your ★ star to the project.