FastAPI psycopg3 Tutorial

FastAPI is a modern, fast (high-performance) web framework for building APIs with Python 3.7+. It is built on top of Starlette for the web parts and Pydantic for the data parts. FastAPI provides a fast way to build web APIs and is gaining popularity due to its speed and simplicity.

What is psycopg3?

psycopg3 is the next generation driver for PostgreSQL. It is a C wrapper for the libpq PostgreSQL client library and provides a Python DB-API 2.0 compliant interface to connect to a PostgreSQL database, execute SQL queries, and manage database connections.

Setting up FastAPI with psycopg3

To start using FastAPI with psycopg3, you need to first install FastAPI and psycopg3 using pip:

        pip install fastapi
        pip install psycopg3
    

Creating a FastAPI application

Next, you can create a FastAPI application. Here’s an example of a simple FastAPI application that connects to a PostgreSQL database using psycopg3:

        from fastapi import FastAPI
        import psycopg3

        app = FastAPI()

        @app.get("/")
        async def read_root():
            conn = psycopg3.connect(
                dbname="mydatabase",
                user="myuser",
                password="mypassword",
                host="localhost"
            )
            cur = conn.cursor()
            cur.execute("SELECT * FROM mytable")
            rows = cur.fetchall()
            conn.close()
            return {"data": rows}
    

Running the FastAPI application

To run the FastAPI application, you can simply use uvicorn:

        uvicorn main:app --reload
    

Conclusion

With FastAPI and psycopg3, you can easily build high-performance web APIs that connect to a PostgreSQL database. FastAPI’s simplicity and speed, combined with psycopg3’s powerful database connectivity, make them an excellent choice for building modern web applications.