sqlmodel-database

SQLModel lets you define database schemas by creating model classes that inherit from SQLModel's base, specifying columns with type hints, and establishing relationships. You define a hierarchy of base models, table models with id and timestamps, and API variants (Create, Read, Update) to separate database and API concerns within FastAPI apps.

Yes. SQLModel supports both sync operations using Session and async operations using AsyncSession. You configure either pattern depending on your FastAPI application's needs, manage session lifecycle through dependency injection, and write async-compatible queries for high-concurrency workloads.

Define relationships using SQLModel's Relationship field with foreign key constraints and back_populates parameters. Establish one-to-many by linking child models to a parent via foreign key, and many-to-many using association tables, then wire them into FastAPI endpoints through dependency injection.

Create a database engine using SQLAlchemy with a PostgreSQL connection string, instantiate Session or AsyncSession from it, and inject sessions into FastAPI route handlers via Depends. This pattern keeps connections managed centrally while routes stay clean and testable.

Alembic is the standard tool for managing schema migrations with SQLModel. It tracks model changes, generates migration scripts, and applies them to your PostgreSQL database, ensuring schema versions stay in sync across environments.

SQLModel models automatically generate OpenAPI schemas when used as FastAPI request/response types. Define separate model classes for Create, Read, and Update operations, use them in route decorators, and FastAPI generates correct documentation and validation without extra configuration.