diff options
Diffstat (limited to 'doc/build/errors.rst')
| -rw-r--r-- | doc/build/errors.rst | 62 |
1 files changed, 30 insertions, 32 deletions
diff --git a/doc/build/errors.rst b/doc/build/errors.rst index 4845963b0..e76263692 100644 --- a/doc/build/errors.rst +++ b/doc/build/errors.rst @@ -211,38 +211,6 @@ each, see the section :ref:`faq_new_caching`. :ref:`faq_new_caching` - in the :ref:`faq_toplevel` section -.. _error_s9r1: - -Object is being merged into a Session along the backref cascade ---------------------------------------------------------------- - -This message refers to the "backref cascade" behavior of SQLAlchemy, -which is described at :ref:`backref_cascade`. This refers to the action of -an object being added into a :class:`_orm.Session` as a result of another -object that's already present in that session being associated with it. -As this behavior has been shown to be more confusing than helpful, -the :paramref:`_orm.relationship.cascade_backrefs` and -:paramref:`_orm.backref.cascade_backrefs` parameters were added, which can -be set to ``False`` to disable it, and in SQLAlchemy 2.0 the "cascade backrefs" -behavior will be disabled completely. - -To set :paramref:`_orm.relationship.cascade_backrefs` to ``False`` on a -backref that is currently configured using the -:paramref:`_orm.relationship.backref` string parameter, the backref must -be declared using the :func:`_orm.backref` function first so that the -:paramref:`_orm.backref.cascade_backrefs` parameter may be passed. - -Alternatively, the entire "cascade backrefs" behavior can be turned off -across the board by using the :class:`_orm.Session` in "future" mode, -by passing ``True`` for the :paramref:`_orm.Session.future` parameter. - -.. seealso:: - - :ref:`backref_cascade` - complete description of the cascade backrefs - behavior - - :ref:`change_5150` - background on the change for SQLAlchemy 2.0. - .. _error_xaj1: An alias is being generated automatically for raw clauseelement @@ -1611,3 +1579,33 @@ In SQLAlchemy 1.4, this :term:`2.0 style` behavior is enabled when the :paramref:`_orm.Session.future` flag is set on :class:`_orm.sessionmaker` or :class:`_orm.Session`. +.. _error_s9r1: + +Object is being merged into a Session along the backref cascade +--------------------------------------------------------------- + +This message refers to the "backref cascade" behavior of SQLAlchemy, +removed in version 2.0. This refers to the action of +an object being added into a :class:`_orm.Session` as a result of another +object that's already present in that session being associated with it. +As this behavior has been shown to be more confusing than helpful, +the :paramref:`_orm.relationship.cascade_backrefs` and +:paramref:`_orm.backref.cascade_backrefs` parameters were added, which can +be set to ``False`` to disable it, and in SQLAlchemy 2.0 the "cascade backrefs" +behavior has been removed entirely. + +For older SQLAlchemy versions, to set +:paramref:`_orm.relationship.cascade_backrefs` to ``False`` on a backref that +is currently configured using the :paramref:`_orm.relationship.backref` string +parameter, the backref must be declared using the :func:`_orm.backref` function +first so that the :paramref:`_orm.backref.cascade_backrefs` parameter may be +passed. + +Alternatively, the entire "cascade backrefs" behavior can be turned off +across the board by using the :class:`_orm.Session` in "future" mode, +by passing ``True`` for the :paramref:`_orm.Session.future` parameter. + +.. seealso:: + + :ref:`change_5150` - background on the change for SQLAlchemy 2.0. + |