Adding a Free PostgreSQL Database to FastAPI Apps

PostgreSQL is a powerful, open-source object-relational database system that is widely used for web applications. By integrating a PostgreSQL database with your FastAPI application, you can store and manage data efficiently. This guide will walk you through the steps of setting up a free PostgreSQL database and using it in your FastAPI application.

Creating a Free PostgreSQL Database

• Sign up for a free PostgreSQL hosting service: There are many options available, such as Heroku, ElephantSQL, and AWS RDS.
• Create a new database and note the connection URL.

Installing Required Libraries

Install the following libraries:

Bash

pip install fastapi uvicorn sqlalchemy psycopg2

Configuring the Database Connection

In your FastAPI application, create a database connection string using the URL provided by your PostgreSQL hosting service:

Python

DATABASE_URL = "postgresql://user:password@host:port/database"

Creating a Database Session

Python

from sqlalchemy.ext.asyncio import create_async_engine
from sqlalchemy.orm import sessionmaker

engine = create_async_engine(DATABASE_URL)   
async_session = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Using the Database in Endpoints

Python

from fastapi import Depends

async def get_db():
    async with async_session() as session:
        yield session

@app.get("/")
async def read_root(db: Session = Depends(get_db)):
    return {"message": "Hello, world!"}

Additional Factors

• Data Models: Define your database models using SQLAlchemy’s declarative base.
• Migrations: Use SQLAlchemy migrations to manage database schema changes.
• Security: Protect your database credentials and ensure proper security measures are in place.
• Performance: Optimize your database queries for performance.