Data Layer

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