Project: CRUD API with Postgres

This project wires Lesson 12 (SQL/Postgres) into Lesson 13 (FastAPI): a real Create-Read-Update-Delete API backed by a real database, not an in-memory list that resets on every restart.

Keep the database connection string in an environment variable, read at startup — never hardcoded in source, since that's a credential that would otherwise sit in your git history forever. Return the right status code for each outcome: 201 for a successful create, 200 for a successful read/update, 204 or 200 for delete, 404 when the id doesn't exist.

import os
DATABASE_URL = os.environ["DATABASE_URL"]

@app.get("/todos/{todo_id}")
def get_todo(todo_id: int):
    row = db.fetch_one(todo_id)
    if row is None:
        raise HTTPException(status_code=404, detail="not found")
    return row