Database Migrations Skill

Context (Input)

•New entity needs database persistence
•Existing entity requires schema changes (add/modify/remove fields)
•Repository implementation needed
•Database schema validation fails
•Need to set up indexes for performance

Task (Function)

Create entities with XML mapping and repositories following hexagonal architecture and relational database best practices (Doctrine ORM, MySQL).

Success Criteria: make setup-test-db runs without errors, schema validates, all tests pass.

Core Principles

Domain-Driven Design

•Entities: Domain layer ({Context}/Domain/Entity/)
•Repository Interfaces: Domain layer ({Context}/Domain/Repository/)
•Repository Implementations: Infrastructure layer ({Context}/Infrastructure/Repository/)
•XML Mappings: Infrastructure concern (config/doctrine/)

See: implementing-ddd-architecture for DDD patterns.

Doctrine ORM (MySQL)

•Use XML mappings for all entity metadata (not annotations/attributes)
•Define indexes in XML for performance
•Use custom types (ULID, DomainUuid) for identifiers
•Schema updates applied via Doctrine migration/ORM commands

Note: Examples inherited from the template show MongoDB/ODM structures. In this project use .orm.xml mappings and Doctrine ORM migrations instead of ODM commands.

Quick Start

Creating a New Entity

Step 1: Create Entity (Domain Layer)

php

// src/Core/{Context}/Domain/Entity/{Entity}.php
namespace App\Core\{Context}\Domain\Entity;

final class Customer
{
    public function __construct(
        private string $id,
        private string $name,
        private string $email,
        private \DateTimeImmutable $createdAt
    ) {}

    // Getters only - no setters (immutability)
}

Step 2: Create XML Mapping

xml

<!-- config/doctrine/Customer.orm.xml -->
<entity name="App\Core\Customer\Domain\Entity\Customer" repository-class="App\Core\Customer\Infrastructure\Repository\CustomerRepository">
    <id name="id" type="domain_uuid"/>
    <field name="name" type="string" length="255"/>
    <field name="email" type="string" length="255" unique="true"/>
    <field name="createdAt" column="created_at" type="datetime_immutable"/>
</entity>

Step 3: Configure API Platform

yaml

# config/api_platform/resources/customer.yaml
App\Core\Customer\Domain\Entity\Customer:
  shortName: Customer
  operations:
    get_collection: ~
    get: ~
    post: ~

Step 4: Update Schema

bash

make cache-clear
docker compose exec php bin/console doctrine:schema:validate

See: entity-creation-guide.md for complete workflow.

Modifying Existing Entities

•Update Entity Class (add/modify fields)
•Update XML Mapping (add field definitions)
•Clear Cache: make cache-clear
•Validate Schema: docker compose exec php bin/console doctrine:schema:validate

See: entity-modification-guide.md

Creating Repositories

Step 1: Define Interface (Domain)

php

// Domain/Repository/CustomerRepositoryInterface.php
interface CustomerRepositoryInterface
{
    public function save(Customer $customer): void;
    public function findById(string $id): ?Customer;
}

Step 2: Implement (Infrastructure)

php

// Infrastructure/Repository/CustomerRepository.php
final class CustomerRepository implements CustomerRepositoryInterface
{
    public function __construct(
        private readonly DocumentManager $documentManager
    ) {}

    public function save(Customer $customer): void
    {
        $this->documentManager->persist($customer);
        $this->documentManager->flush();
    }
}

Step 3: Register in services.yaml

yaml

App\Core\Customer\Domain\Repository\CustomerRepositoryInterface:
  alias: App\Core\Customer\Infrastructure\Repository\CustomerRepository

See: repository-patterns.md

Database-Specific Features (Doctrine ORM/MySQL)

Custom Types

Type	Usage	Purpose
`ulid`	Primary/foreign keys	Sortable, time-ordered identifiers
`domain_uuid`	Domain identifiers	Standard UUID format (RFC 4122)

xml

<id name="id" type="domain_uuid"/>
<field name="token" type="ulid"/>

Indexes & Constraints

•Use unique=\"true\" on fields or <unique-constraint> elements for uniqueness (e.g., email).
•Add <indexes> with <index name=\"idx_email\" columns=\"email\"/> for frequent lookups.
•Always index columns used in filters/sorting (email, token, foreign keys, timestamps).

Relationships & Value Objects

•Model associations with Doctrine relations (one-to-one, one-to-many, many-to-many).
•Persist value objects as simple fields; avoid framework validation inside Domain.

Available Commands

bash

# Schema Management
make doctrine-migrations-migrate        # Apply pending migrations
make doctrine-migrations-generate       # Create empty migration file
make setup-test-db                      # Drop and recreate test database

# Schema Operations
docker compose exec php bin/console doctrine:schema:validate             # Validate schema

Constraints (Parameters)

NEVER

•Use Doctrine annotations/attributes in Domain entities
•Modify existing migrations after they're applied
•Skip XML mapping validation
•Leave empty migration files in codebase
•Commit without testing schema changes
•Skip make setup-test-db before integration tests

ALWAYS

•Create XML mappings for all entity metadata
•Keep Domain entities framework-agnostic
•Define indexes for frequently queried fields
•Test migrations on dev database before committing
•Run make setup-test-db to verify schema
•Use Faker for unique test data (emails, names, etc.)
•Register resource directories in api_platform.yaml

Format (Output)

Expected Schema Validation Output

bash

$ docker compose exec php bin/console doctrine:schema:validate
Mapping files are correct.

Expected Test DB Setup Output

bash

$ make setup-test-db
Database dropped and recreated successfully

Verification Checklist

After entity/migration changes:

Related Skills

•implementing-ddd-architecture - DDD patterns and repository interfaces
•api-platform-crud - Configuring API Platform resources
•deptrac-fixer - Fixing architectural violations

Quick Commands

bash

# Validate schema
docker compose exec php bin/console doctrine:schema:validate

# Setup test database
make setup-test-db

# Clear cache after config changes
make cache-clear

# Run migrations
make doctrine-migrations-generate
make doctrine-migrations-migrate

Reference Documentation

Detailed guides and examples:

•entity-creation-guide.md - Complete entity creation workflow
•entity-modification-guide.md - Modifying existing entities
•repository-patterns.md - Repository implementation patterns
•mongodb-specifics.md - Database-specific notes (adapt from template)
•reference/troubleshooting.md - Common issues and solutions
•examples/ - Complete working examples

Migration Best Practices

1. Clean Up Empty Migrations

MANDATORY: Delete empty migrations immediately.

php

// ❌ DELETE: No actual changes
public function up(Schema $schema): void { }
public function down(Schema $schema): void { }

2. Test Before Committing

•Apply migration on dev database
•Verify schema: doctrine:schema:validate
•Run all tests
•Test rollback if applicable

3. Production Safety

bash

# Always backup before migration
# Apply migration
make doctrine-migrations-migrate
# Verify application works
# Keep backup for potential rollback

Testing with Database

Setup Test Database

bash

make setup-test-db  # Before integration/E2E tests

Integration Test Pattern

php

final class CustomerRepositoryTest extends IntegrationTestCase
{
    private CustomerRepositoryInterface $repository;

    protected function setUp(): void
    {
        parent::setUp();
        $this->repository = $this->getContainer()->get(CustomerRepositoryInterface::class);
    }

    public function testSaveAndRetrieveCustomer(): void
    {
        $customer = new Customer(/* unique test data with Faker */);
        $this->repository->save($customer);

        $retrieved = $this->repository->findById($customer->getId());
        $this->assertNotNull($retrieved);
    }
}

Important: Always use Faker for unique test data.

Troubleshooting

Common Issues

Database Connection Errors:

bash

docker compose ps database
docker compose logs database

Schema Sync Issues:

bash

docker compose exec php bin/console doctrine:schema:validate
docker compose exec php bin/console doctrine:migrations:status

Migration Conflicts:

bash

docker compose exec php bin/console doctrine:migrations:status
docker compose exec php bin/console doctrine:migrations:migrate prev  # Rollback

See: reference/troubleshooting.md for comprehensive guide.