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| author | Russell Keith-Magee <russell@keith-magee.com> | 2013-09-30 13:05:43 +0800 |
|---|---|---|
| committer | Russell Keith-Magee <russell@keith-magee.com> | 2013-09-30 13:05:43 +0800 |
| commit | 9595183d03cfd0d94ae2dd506a3d2b86cf5c74a7 (patch) | |
| tree | acf9e2846cce92c9f01f0f5aa19293d7cedfa021 /docs | |
| parent | 12ca312e1bc2cab614aed854b4c38dd86fefbdda (diff) | |
Fixed #13724: Corrected routing of write queries involving managers.
Previously, if a database request spanned a related object manager, the
first manager encountered would cause a request to the router, and this
would bind all subsequent queries to the same database returned by the
router. Unfortunately, the first router query would be performed using
a read request to the router, resulting in bad routing information being
used if the subsequent query was actually a write.
This change defers the call to the router until the final query is acutally
made.
It includes a small *BACKWARDS INCOMPATIBILITY* on an edge case - see the
release notes for details.
Thanks to Paul Collins (@paulcollinsiii) for the excellent debugging
work and patch.
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/releases/1.7.txt | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/docs/releases/1.7.txt b/docs/releases/1.7.txt index 573ad49dc2..74fc74947c 100644 --- a/docs/releases/1.7.txt +++ b/docs/releases/1.7.txt @@ -368,6 +368,20 @@ For apps with migrations, ``allow_migrate`` will now get passed without custom attributes, methods or managers. Make sure your ``allow_migrate`` methods are only referring to fields or other items in ``model._meta``. +Passing ``None`` to ``Manager.db_manager()`` +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +In previous versions of Django, it was possible to use +``db_manager(using=None)`` on a model manager instance to obtain a manager +instance using default routing behavior, overriding any manually specified +database routing. In Django 1.7, a value of ``None`` passed to db_manager will +produce a router that *retains* any manually assigned database routing -- the +manager will *not* be reset. This was necessary to resolve an inconsistency in +the way routing information cascaded over joins. See `Ticket #13724`_ for more +details. + +.. _Ticket #13724: https://code.djangoproject.com/ticket/13724 + pytz may be required ~~~~~~~~~~~~~~~~~~~~ |