🔒 FastAPI, GraphQL and Strawberry integration issue

[coral idol]

Hello everyone! I'm new to the group and generally to GraphQL. I'm having an issue with my code and I'm lost on what to do.
This is the mutations file I'm currently using:

import strawberry
from app.schemas import BookType, AuthorType
from app.db import get_db
from app.models import Book, Author

@strawberry.type
class Mutation:
    @strawberry.mutation
    async def add_book(self, title: str, author_id: int) -> BookType:
        async with get_db() as db:  # Using the database session dependency
            new_book = Book(title=title, author_id=author_id)  # Create a new book instance
            db.add(new_book)  # Add the new book to the session
            await db.commit()  # Commit the transaction
            await db.refresh(new_book)  # Refresh the instance to reflect the database state
            return new_book  # Return the newly created book

    @strawberry.mutation
    async def add_author(self, name: str) -> AuthorType:
        async with get_db() as db:  # Using the database session dependency
            new_author = Author(name=name)  # Create a new author instance
            db.add(new_author)  # Add the new author to the session
            await db.commit()  # Commit the transaction
            await db.refresh(new_author)  # Refresh the instance to reflect the database state
            return new_author  # Return the newly created author

If I try:

mutation {
  addAuthor(name: "George Orwell") {
    id
    name
  }
}

[teal stratus]

@coral idol

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[coral idol]

I get the following error:
async with get_db() as db: # Using the database session dependency
TypeError: 'async_generator' object does not support the asynchronous context manager protocol

from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
from sqlalchemy.orm import sessionmaker, declarative_base
from config import settings
from typing import AsyncGenerator

engine = create_async_engine(settings.DATABASE_URL, echo=True)
SessionLocal = sessionmaker(bind=engine, 
                            class_=AsyncSession, 
                            expire_on_commit=False)

# Function to provide the database session, used as a dependency in FastAPI routes
async def get_db() -> AsyncGenerator[AsyncSession, None]:
    async with SessionLocal() as session:
        yield session

[rapid spear]

you might need to decorate your get_db function with @asynccontextmanager from contextlib

[coral idol]

Ohhhh ok ok, let me try really fast. Thanks

[rapid spear]

https://docs.python.org/3/library/contextlib.html#contextlib.asynccontextmanager

[coral idol]

OMG that was it it seems! Thank you so much! I've been agonizing for hrs on this.
I did try the asynccontextmanager on the lifespan for FastAPI

@asynccontextmanager
async def lifespan(app: FastAPI):
    await init_db()  # Initialize the database
    yield
    # Here you can add any teardown code if needed

Seems like it wasn't enough. Thank you so much!

[teal stratus]

Python help channel closed

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