ormar

What it is and what it does

Ormar is an async ORM built on SQLAlchemy core that lets you define a single model class that serves both as a database schema definition and as a pydantic validation schema. This eliminates the common pattern of maintaining separate ORM models and request/response validation schemas. It supports Postgres, MySQL, and SQLite through async drivers, making it a natural fit for async web frameworks like FastAPI and Starlette.

The package integrates pydantic's validation layer directly into the ORM, so your model fields are both database columns and validated request/response fields. You define relationships, constraints, and field types once, then use the same model class for database queries, API request bodies, and API responses. It handles async database operations throughout—queries, inserts, updates, and relationship loading all use await syntax.

Use it for

• Build FastAPI applications where the same model class validates incoming requests and represents database records.
• Create async web services that need to query Postgres, MySQL, or SQLite without maintaining parallel pydantic and ORM schemas.
• Migrate existing SQLAlchemy projects to async using the sqlalchemy-to-ormar translation tool.
• Define relationships and foreign keys in a single model that automatically works as both ORM and API schema.
• Use with fastapi-crudrouter or fastapi-pagination for automatic CRUD endpoints and pagination support.

Worth the install?

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Install

ormar on PyPI

Before you install

Low friction installation with a pure-Python wheel. The package is actively maintained with a recent release and no known vulnerabilities. It depends on four runtime packages (SQLAlchemy, orjson, ormar-utils, pydantic) that are themselves well-established.

Requires Python 3.10 or later. Async operations must be awaited within an async context (e.g., inside an async function or FastAPI route handler).

License in practice

MIT license permits commercial and private use with minimal restrictions. The package is explicitly open-source and free, with the maintainer accepting sponsorship but making no license-based demands.

Quickstart

import ormar
import sqlalchemy

DATABASE_URL = "sqlite+aiosqlite:///db.sqlite"
base_config = ormar.OrmarConfig(
    database=ormar.DatabaseConnection(DATABASE_URL),
    metadata=sqlalchemy.MetaData(),
)

class Author(ormar.Model):
    ormar_config = base_config.copy(tablename="authors")
    id: int = ormar.Integer(primary_key=True)
    name: str = ormar.String(max_length=100)

Package facts

Evidence: ormar-0.26.0-py3-none-any.whl

Tags

More WWW/HTTP packages

See also ormar-utils · sqlmodel · fastcrud · databases · fastapi-users-db-sqlalchemy · tortoise-orm · prisma · FastAPI-SQLAlchemy · piccolo · async-factory-boy