In Django 4.2, calling manager methods on non-persisted instances is no longer allowed. This change causes Account.save() to fail on any Account that hasn't been previously saved, because the Account._balance() method calls self.transactions.aggregate() before the Account is in the database:
File ".../helpers.py", line 320, in create_account
account_type.accounts.create(
File ".../lib/python3.8/site-packages/django/db/models/fields/related_descriptors.py", line 799, in create
return super(RelatedManager, self.db_manager(db)).create(**kwargs)
File ".../lib/python3.8/site-packages/django/db/models/manager.py", line 87, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File ".../lib/python3.8/site-packages/django/db/models/query.py", line 658, in create
obj.save(force_insert=True, using=self.db)
File ".../lib/python3.8/site-packages/oscar_accounts/abstract_models.py", line 149, in save
self.balance = self._balance()
File ".../lib/python3.8/site-packages/oscar_accounts/abstract_models.py", line 153, in _balance
aggregates = self.transactions.aggregate(sum=Sum('amount'))
File ".../lib/python3.8/site-packages/django/db/models/manager.py", line 87, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File ".../lib/python3.8/site-packages/django/db/models/fields/related_descriptors.py", line 718, in get_queryset
raise ValueError(
ValueError: 'Account' instance needs to have a primary key value before this relationship can be used.
In Django 4.2, calling manager methods on non-persisted instances is no longer allowed. This change causes
Account.save()to fail on any Account that hasn't been previously saved, because theAccount._balance()method callsself.transactions.aggregate()before the Account is in the database: