FastAPI with SQLAlchemy - Multiple Async Calls Resulting in Inconsistent Data Retrieval
I'm working through a tutorial and I'm working with an scenario with inconsistent data retrieval when using FastAPI with SQLAlchemy in an asynchronous context... I'm trying to fetch user profiles from my database, but when I make multiple async calls, the results seem to mix up, returning profiles that don't correspond with the user IDs requested. Here’s a simplified version of my code: ```python from fastapi import FastAPI, Depends, HTTPException from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine from sqlalchemy.orm import sessionmaker, declarative_base from sqlalchemy import Column, Integer, String DATABASE_URL = "postgresql+asyncpg://user:password@localhost/dbname" engine = create_async_engine(DATABASE_URL, echo=True) Base = declarative_base() SessionLocal = sessionmaker(bind=engine, class_=AsyncSession, expire_on_commit=False) class User(Base): __tablename__ = 'users' id = Column(Integer, primary_key=True, index=True) name = Column(String, index=True) app = FastAPI() async def get_db(): async with SessionLocal() as session: yield session @app.get("/users/{user_id}") async def read_user(user_id: int, db: AsyncSession = Depends(get_db)): user = await db.get(User, user_id) if user is None: raise HTTPException(status_code=404, detail="User not found") return user ``` When I hit the endpoint multiple times, I often receive the correct data, but sometimes, the returned user data corresponds to a different user ID than requested. I’ve tried ensuring that the session is instantiated correctly and that I’m awaiting the database call, yet the question continues. I also checked the database connection settings and increased the connection pool size, but it hasn’t made a difference. It seems like there could be a race condition, or I might be missing something in terms of session handling. Any advice on what could be going wrong here would be greatly appreciated! The project is a microservice built with Python. For context: I'm using Python on Windows 10. Am I missing something obvious?