fastapi-toolsets/docs/migration/v4.md

Migrating to v4.0

This page covers every breaking change introduced in v4.0 and the steps required to update your code.

---

Database

lock_tables now takes a session_maker instead of a session

The first argument of lock_tables changed from an AsyncSession instance to an async_sessionmaker. The function creates and manages its own dedicated session internally, yielding it to the caller.

=== "Before (v3)"

```python
from fastapi_toolsets.db import lock_tables, LockMode

async with lock_tables(session=session, tables=[User, Account]):
    user = await UserCrud.get(session, [User.id == 1])
    user.balance += 100

# With a custom lock mode
async with lock_tables(session=session, tables=[Order], mode=LockMode.EXCLUSIVE):
    await process_order(session, order_id)
```

=== "Now (v4)"

```python
from fastapi_toolsets.db import lock_tables, LockMode

async with lock_tables(session_maker=session_maker, tables=[User, Account]) as session:
    user = await UserCrud.get(session, [User.id == 1])
    user.balance += 100

# With a custom lock mode
async with lock_tables(
    session_maker=session_maker, tables=[Order], mode=LockMode.EXCLUSIVE
) as session:
    await process_order(session, order_id)
```