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Data Layer

Persist authors and posts with Doctrine and MySQL.

Goal

This snapshot advances Keystone Gazette by teaching you to persist authors and posts with Doctrine and MySQL.

Every numbered folder is a complete app. Run this stage independently, then compare it with the previous folder.

Prerequisites

Use PHP 8.2+, Composer, and Docker for MySQL stages.

Port 8002 must be free. Copy .env.example before starting database stages.

  • PHP 8.2+ and Composer
  • A code editor and terminal
  • Docker from part 4 onward

Concepts

Doctrine entities map tables. Each snapshot uses its own keystone database.

Keep controllers thin: forms accept input, Doctrine entities enforce rules, and Twig escapes output by default.

Walkthrough

Configure DATABASE_URL, create User and Post entities, seed Ada and Grace.

Read the example, then open the matching snapshot. The repository includes the surrounding setup and error handling.

$posts = $em->getRepository(Post::class)->findBy([], ['createdAt' => 'DESC']);

Run and verify

Enter 04-Data-Layer, install Composer deps, copy .env.example, and start the Symfony server on port 8002.

Open http://127.0.0.1:8002. Watch the terminal for validation and database errors.

docker compose up -d
git clone https://github.com/michaeldunga1/fcc-symfony-blog.git
cd fcc-symfony-blog/04-Data-Layer
composer install
cp .env.example .env
symfony server:start --port=8002 --no-tls
# or: php -S 127.0.0.1:8002 -t public

Troubleshooting

Connection refused usually means Docker MySQL is stopped or the port is not 3309.

For database failures, confirm Docker and the keystone_NN name when applicable. Never commit .env or vendor.

  • Read the first error first
  • Restart after environment changes
  • Never commit secrets

Try this

Add a minimum title length check before flush.

Test a happy path and one invalid or unauthorized request.

  • Make one small change
  • Test it in the browser
  • Compare with the next snapshot only after it works

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