diff options
Diffstat (limited to 'lib/sqlalchemy')
| -rw-r--r-- | lib/sqlalchemy/orm/__init__.py | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/lib/sqlalchemy/orm/__init__.py b/lib/sqlalchemy/orm/__init__.py index ec4f39fdf..afb64d491 100644 --- a/lib/sqlalchemy/orm/__init__.py +++ b/lib/sqlalchemy/orm/__init__.py @@ -295,10 +295,13 @@ def relationship(argument, secondary=None, **kwargs): * ``delete`` - cascade the :meth:`.Session.delete` operation - * ``delete-orphan`` - if an item of the child's type with no - parent is detected, mark it for deletion. Note that this - option prevents a pending item of the child's class from being - persisted without a parent present. + * ``delete-orphan`` - if an item of the child's type is + detached from its parent, mark it for deletion. + As of version 0.7, this option does not prevent + a new instance of the child object from being persisted + without a parent to start with; to constrain against + that case, ensure the child's foreign key column(s) + is configured as NOT NULL * ``refresh-expire`` - cascade the :meth:`.Session.expire` and :meth:`~sqlalchemy.orm.session.Session.refresh` operations @@ -306,6 +309,9 @@ def relationship(argument, secondary=None, **kwargs): * ``all`` - shorthand for "save-update,merge, refresh-expire, expunge, delete" + See the section :ref:`unitofwork_cascades` for more background + on configuring cascades. + :param cascade_backrefs=True: a boolean value indicating if the ``save-update`` cascade should operate along an assignment event intercepted by a backref. @@ -332,7 +338,8 @@ def relationship(argument, secondary=None, **kwargs): ) }) - ``cascade_backrefs`` is new in 0.6.5. + See the section :ref:`unitofwork_cascades` for more background + on configuring cascades. :param collection_class: a class or callable that returns a new list-holding object. will |