Populate `created_at` and `updated_at` columns with Symfony & Doctrine.

Example.php

<?php

namespace App\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity(repositoryClass="App\Repository\ExampleRepository")
 * @ORM\HasLifecycleCallbacks()
 * @ORM\Table("examples")
 */
class Example
{
    use Timestamps;

    // ...more fields
}

Timestamps.php

<?php

namespace App\Entity;

use DateTime;
use DateTimeInterface;
use Doctrine\ORM\Mapping as ORM;

trait Timestamps
{
    /**
     * @ORM\Column(name="created_at", type="datetime", nullable=true)
     */
    private $createdAt;

    /**
     * @ORM\Column(name="updated_at", type="datetime", nullable=true)
     */
    private $updatedAt;

    public function getCreatedAt(): ?DateTimeInterface
    {
        return $this->createdAt;
    }

    public function setCreatedAt(?DateTimeInterface $timestamp): self
    {
        $this->createdAt = $timestamp;
        return $this;
    }

    public function getUpdatedAt(): ?DateTimeInterface
    {
        return $this->updatedAt;
    }

    public function setUpdatedAt(?DateTimeInterface $timestamp): self
    {
        $this->updatedAt = $timestamp;
        return $this;
    }

    /**
     * @ORM\PrePersist
     */
    public function setCreatedAtAutomatically()
    {
        if ($this->getCreatedAt() === null) {
            $this->setCreatedAt(new \DateTime());
        }
    }

    /**
     * @ORM\PreUpdate
     */
    public function setUpdatedAtAutomatically()
    {
        $this->setUpdatedAt(new \DateTime());
    }
}

Version00000000000000.php

<?php

declare(strict_types=1);

namespace DoctrineMigrations;

use Doctrine\DBAL\Schema\Schema;
use Doctrine\DBAL\Types\Type;
use Doctrine\Migrations\AbstractMigration;

final class Version00000000000000 extends AbstractMigration
{
    public function up(Schema $schema) : void
    {
        $table = $schema->createTable('examples');
        // ...more fields
        $table->addColumn('created_at', Type::DATETIME, ['notnull' => false]);
        $table->addColumn('updated_at', Type::DATETIME, ['notnull' => false]);
    }

    public function down(Schema $schema) : void
    {
        $schema->dropTable('examples');
    }
}

Just did, thanks!