Skip to main content

Adds simple SQLAlchemy support to FastAPI

Project description

https://github.com/mfreeborn/fastapi-sqlalchemy/workflows/ci/badge.svg https://codecov.io/gh/mfreeborn/fastapi-sqlalchemy/branch/master/graph/badge.svg https://img.shields.io/pypi/v/fastapi_sqlalchemy?color=blue

FastAPI-SQLAlchemy provides a simple integration between FastAPI and SQLAlchemy in your application. It gives access to useful helpers to facilitate the completion of common tasks.

Installing

Install and update using pip:

$ pip install fastapi-sqlalchemy

Examples

Usage inside of a route

from fastapi import FastAPI
from fastapi_sqlalchemy import DBSessionMiddleware  # middleware helper
from fastapi_sqlalchemy import db  # an object to provide global access to a database session

from app.models import User

app = FastAPI()

app.add_middleware(DBSessionMiddleware, db_url="sqlite://")

# once the middleware is applied, any route can then access the database session
# from the global ``db``

@app.get("/users")
def get_users():
    users = db.session.query(User).all()

    return users

Note that the session object provided by db.session is based on the Python3.7+ ContextVar. This means that each session is linked to the individual request context in which it was created.

Usage outside of a route

Sometimes it is useful to be able to access the database outside the context of a request, such as in scheduled tasks which run in the background:

import pytz
from apscheduler.schedulers.asyncio import AsyncIOScheduler  # other schedulers are available
from fastapi import FastAPI
from fastapi_sqlalchemy import db

from app.models import User, UserCount

app = FastAPI()

app.add_middleware(DBSessionMiddleware, db_url="sqlite://")


@app.on_event('startup')
async def startup_event():
    scheduler = AsyncIOScheduler(timezone=pytz.utc)
    scheduler.start()
    scheduler.add_job(count_users_task, "cron", hour=0)  # runs every night at midnight


def count_users_task():
    """Count the number of users in the database and save it into the user_counts table."""

    # we are outside of a request context, therefore we cannot rely on ``DBSessionMiddleware``
    # to create a database session for us. Instead, we can use the same ``db`` object and
    # use it as a context manager, like so:

    with db():
        user_count = db.session.query(User).count()

        db.session.add(UserCount(user_count))
        db.session.commit()

    # no longer able to access a database session once the db() context manager has ended

    return users

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

FastAPI-SQLAlchemy-0.2.1.tar.gz (4.4 kB view hashes)

Uploaded source

Built Distribution

FastAPI_SQLAlchemy-0.2.1-py3-none-any.whl (5.7 kB view hashes)

Uploaded py3

Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page