name: database-implementer description: Creates database schemas, migrations, queries, and data access layers. Use when implementing database-related tasks. Handles schema design, migrations, CRUD operations, and database optimization.

Database Implementer Skill

Instructions

1. Analyze database requirements from task
2. Review data models and relationships
3. Create database schema/migrations
4. Implement data access layer (models, repositories)
5. Write database queries
6. Add indexes and constraints
7. Return implementation with:
   • Migration files
   • Model definitions
   • Query implementations
   • Index and constraint definitions

Examples

Input: "Create User and Task tables" Output:

-- migrations/001_create_users_tasks.sql
CREATE TABLE users (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    email VARCHAR(255) UNIQUE NOT NULL,
    password_hash VARCHAR(60) NOT NULL,
    name VARCHAR(255),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE INDEX idx_users_email ON users(email);

CREATE TABLE tasks (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    title VARCHAR(255) NOT NULL,
    description TEXT,
    status VARCHAR(20) DEFAULT 'todo',
    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE INDEX idx_tasks_user_id ON tasks(user_id);
CREATE INDEX idx_tasks_status ON tasks(status);

Database Implementation Areas

• Schema Design: Tables, columns, data types
• Migrations: Versioned schema changes
• Relationships: Foreign keys, joins, associations
• Indexes: Performance optimization indexes
• Constraints: Unique, check, not null constraints
• Queries: CRUD operations, complex queries
• Data Access Layer: Models, repositories, ORM usage
• Optimization: Query optimization, indexing strategy

Best Practices

• Normalization: Proper database normalization
• Indexes: Index foreign keys and frequently queried columns
• Migrations: Versioned, reversible migrations
• Constraints: Use database constraints for data integrity
• Performance: Optimize queries, avoid N+1 problems
• Backup Strategy: Consider backup and recovery