orm

Fix NameError in SQLAlchemy order_by() for descending sort. Use desc() import or column.desc() to ORDER BY amount DESC with joins and filters. Complete examples for sql alchemy queries.

Learn why SQLAlchemy mapped_column onupdate=func.now() doesn't trigger with setattr or bulk updates. Fix automatic timestamp updates in ORM, bulk_update_mappings, and Query.update with code examples and best practices.

Swap through_fields order to fix reversed user_from/user_to in Django self-referential ManyToMany through model. Examples, migration steps, and data-fix tips.