👀 Views: 153 💬 Answers: 1 📅 Created: 2025-06-10

fastapi sqlalchemy async postgresql Python

I've been banging my head against this for hours... I'm trying to perform bulk inserts into a PostgreSQL database using FastAPI with SQLAlchemy and async/await. However, I'm working with a `NoSuchModuleError` when I attempt to execute the insert operation. My setup includes FastAPI v0.68.0, SQLAlchemy v1.4.25, and asyncpg for the PostgreSQL connection. Here’s a simplified version of my code: ```python from fastapi import FastAPI from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine from sqlalchemy.orm import sessionmaker from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String, insert DATABASE_URL = "postgresql+asyncpg://user:password@localhost/dbname" engine = create_async_engine(DATABASE_URL, echo=True) Base = declarative_base() class User(Base): __tablename__ = 'users' id = Column(Integer, primary_key=True) name = Column(String) async_session = sessionmaker(bind=engine, class_=AsyncSession, expire_on_commit=False) app = FastAPI() @app.post("/users/bulk/") async def create_users(users: List[User]): async with async_session() as session: async with session.begin(): stmt = insert(User).values(users) await session.execute(stmt) return {"message": "Users created successfully"} ``` When I run this code and send a POST request to `/users/bulk/`, I receive the following behavior: ``` sqlalchemy.exc.NoSuchModuleError: need to load plugin: sqlalchemy.dialects:postgresql.asyncpg ``` I double-checked that I have the `asyncpg` package installed, and it is available in my environment. I also ensured that my connection string is formatted correctly. I've tried changing the database URL to `postgresql://` instead of `postgresql+asyncpg://`, but that just leads to a different behavior about sync drivers. What could be causing this scenario, and how can I properly configure my FastAPI application to perform bulk inserts with async SQLAlchemy? Any ideas what could be causing this?