database-migrations

name	database-migrations
description	Create, manage, and apply database migrations using Doctrine ODM for MongoDB. Use when modifying entities, adding fields, managing database schema changes, creating repositories, or troubleshooting database issues.

Database Migrations Skill

Context (Input)

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

Task (Function)

Create entities with XML mapping and repositories following hexagonal architecture and MongoDB best practices.

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.

MongoDB with Doctrine ODM

• 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 commands

---

Quick Start

Creating a New Entity

Step 1: Create Entity (Domain Layer)

// 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

<!-- config/doctrine/Customer.mongodb.xml -->
<document name="App\Core\Customer\Domain\Entity\Customer" collection="customers">
    <field name="id" fieldName="id" id="true" type="ulid"/>
    <field name="name" type="string"/>
    <field name="email" type="string"/>
    <field name="createdAt" fieldName="created_at" type="date_immutable"/>

    <indexes>
        <index><key name="email" order="asc"/><option name="unique" value="true"/></index>
    </indexes>
</document>

Step 3: Configure API Platform

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

Step 4: Update Schema

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

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

---

Modifying Existing Entities

1. Update Entity Class (add/modify fields)
2. Update XML Mapping (add field definitions)
3. Clear Cache: make cache-clear
4. Update Schema: docker compose exec php bin/console doctrine:mongodb:schema:update

See: entity-modification-guide.md

---

Creating Repositories

Step 1: Define Interface (Domain)

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

Step 2: Implement (Infrastructure)

// 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

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

See: repository-patterns.md

---

MongoDB-Specific Features

Custom Types

Type	Usage	Purpose
ulid	MongoDB _id field	Sortable, time-ordered identifiers
domain_uuid	Domain identifiers	Standard UUID format (RFC 4122)

<field name="ulid" id="true" type="ulid"/>
<field name="customerId" type="domain_uuid"/>

Indexes

<indexes>
    <!-- Unique index -->
    <index><key name="email" order="asc"/><option name="unique" value="true"/></index>

    <!-- Performance index -->
    <index><key name="createdAt" order="desc"/></index>

    <!-- Compound index -->
    <index><key name="status"/><key name="type"/></index>
</indexes>

Embedded Documents

For Value Objects:

<embed-one field="address" target-document="App\Core\Customer\Domain\ValueObject\Address"/>
<embed-many field="tags" target-document="App\Core\Customer\Domain\ValueObject\Tag"/>

See: mongodb-specifics.md

---

Available Commands

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

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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

$ docker compose exec php bin/console doctrine:mongodb:schema:validate
The MongoDB schema is valid.

Expected Test DB Setup Output

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

---

Verification Checklist

After entity/migration changes:

• Entity defined in Domain layer (no framework imports)
• XML mapping created in config/doctrine/
• API Platform resource configured (if needed)
• Repository interface in Domain layer
• Repository implementation in Infrastructure layer
• Repository registered in services.yaml
• Schema validates: doctrine:mongodb:schema:validate
• Test database setup works: make setup-test-db
• All integration tests pass
• make deptrac passes (no violations)
• make ci passes

---

Related Skills

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

---

Quick Commands

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

# Update schema
docker compose exec php bin/console doctrine:mongodb:schema:update

# Setup test database
make setup-test-db

# Clear cache after config changes
make cache-clear

---

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 - MongoDB features and patterns
• reference/troubleshooting.md - Common issues and solutions
• examples/ - Complete working examples

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Migration Best Practices

1. Clean Up Empty Migrations

MANDATORY: Delete empty migrations immediately.

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

2. Test Before Committing

1. Apply migration on dev database
2. Verify schema: doctrine:mongodb:schema:validate
3. Run all tests
4. Test rollback if applicable

3. Production Safety

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

---

Testing with Database

Setup Test Database

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

Integration Test Pattern

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:

docker compose ps mongodb
docker compose logs mongodb

Schema Sync Issues:

docker compose exec php bin/console doctrine:mongodb:schema:validate
docker compose exec php bin/console doctrine:mongodb:schema:update --force

Migration Conflicts:

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.