# sqlalchemy.orm.exc.DetachedInstanceError: Parent instance <User at 0x7f...> is not bound to a Session; lazy load operation of attribute 'orders' cannot proceed

- **ID:** `python/sqlalchemy-lazy-load-race-condition`
- **Domain:** python
- **Category:** runtime_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Accessing a lazy-loaded relationship after the session has been closed or the object has been detached.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   from sqlalchemy.orm import joinedload
user = session.query(User).options(joinedload(User.orders)).first()
# Now access user.orders after session close works
   ```
2. **** (80% success)
   ```
   new_session = Session()
new_session.add(user)
new_session.refresh(user)
orders = user.orders  # now works
   ```

## Dead Ends

- **** — The object remains detached; lazy load still fails unless refresh is performed. (60% fail)
- **** — Same issue; closing session detaches objects. (90% fail)