What problem does it solve? Building database-backed Python applications requires writing correct ORM models, efficient queries, schema migrations, and session management, which is error-prone without established patterns. ## Core Features & Use Cases - Declarative Models with Type Hints: Define tables using SQLAlchemy 2.0 Mapped types, mapped_column, and relationship mappings for one-to-many and many-to-many associations. - Query Builder and CRUD Operations: Compose select, join, eager loading, bulk insert, update, and delete statements with the modern select() API. - Alembic Migrations and Async Support: Generate and apply schema migrations with Alembic and run async database operations with AsyncSession for FastAPI applications. - Use Case: When building a FastAPI service backed by PostgreSQL, use this Skill to define typed models, wire up session dependency injection, write N+1-free queries, and manage schema changes through Alembic revisions. ## Quick Start Ask the AI to create SQLAlchemy 2.0 models with relationships and a FastAPI endpoint that queries them using an async session.