Trouble with Nested Asynchronous Database Transactions in Python 3.11 Using SQLAlchemy
I'm trying to figure out I'm a bit lost with This might be a silly question, but While developing a feature that requires nested asynchronous transactions with SQLAlchemy in Python 3.11, I've run into some unexpected behavior... The goal is to have a parent transaction that can spawn multiple child transactions, but it seems that SQLAlchemy does not handle this as expected when using async sessions. After researching and trying various approaches, I implemented the following code: ```python from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker from sqlalchemy.orm import sessionmaker DATABASE_URL = 'postgresql+asyncpg://user:password@localhost/dbname' engine = create_async_engine(DATABASE_URL, echo=True) session_local = async_sessionmaker(bind=engine, class_=AsyncSession, expire_on_commit=False) async def async_main(): async with session_local() as session: async with session.begin(): # Parent transaction # Perform some operations await session.execute('INSERT INTO table_name (column) VALUES (:value)', {'value': 'test'}) async with session.begin(): # Child transaction await session.execute('INSERT INTO table_name (column) VALUES (:value)', {'value': 'child_test'}) ``` Running this code results in the following error: ``` sqlalchemy.exc.InvalidRequestError: A transaction is already begun. Nesting is not allowed. ``` I’ve tried using `session.commit()` in the child transaction, but it raises the same error. It seems that SQLAlchemy expects the parent transaction to be completed before starting a new one. I also explored `begin_nested()` as a potential solution, but it doesn't seem to work with async sessions either. As we're pushing to meet a deadline, I’m looking for suggestions on how to structure these nested transactions correctly, or if there is a workaround for this design pattern within SQLAlchemy's async capabilities. Any insights or best practices would be greatly appreciated! For context: I'm using Python on Windows. I'd really appreciate any guidance on this. Thanks in advance! I've been using Python for about a year now. Any examples would be super helpful. I'm coming from a different tech stack and learning Python. Cheers for any assistance!