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Fixed #3226: removed some pre-magic-removal-isms in settings docs. Th…

…anks, ubernostrum.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4280 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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commit da9affa8f820d8d3043379a8707511ecaaf11cf0 1 parent 3d38e5d
@jacobian jacobian authored
Showing with 75 additions and 9 deletions.
  1. +72 −6 docs/db-api.txt
  2. +3 −3 docs/settings.txt
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78 docs/db-api.txt
@@ -121,19 +121,37 @@ objects, when you're confident you won't have primary-key collision.
Saving changes to objects
=========================
-To save changes to an object that's already in the database, use ``save()``.
+``save()``
+----------
-Given a ``Blog`` instance ``b5`` that has already been saved to the database,
-this example changes its name and updates its record in the database::
+Use the ``save()`` method to save an object to the database after making
+changes to it::
- b5.name = 'New name'
- b5.save()
+ newblog.name = "Brave New World"
+ newblog.save()
-This performs an ``UPDATE`` SQL statement behind the scenes. Django doesn't hit
+This performs an ``UPDATE`` SQL statement behind the scenes (see the
+`How Django knows to UPDATE vs. INSERT`_ section below). Django doesn't hit
the database until you explicitly call ``save()``.
The ``save()`` method has no return value.
+``update(**kwargs)``
+--------------------
+
+**New in Django development version**
+
+A convenience method for updating and saving an object all in one step, where
+(``**kwargs``) are the attributes to update. Like ``save()``, the
+``update()`` method has no return value.
+
+Using ``update()``, the above code example could be rewritten as::
+
+ newblog.update(name="Brave New World")
+
+Since ``update()`` calls ``save()`` behind the scenes, Django will hit the
+database every time ``update()`` is called.
+
How Django knows to UPDATE vs. INSERT
-------------------------------------
@@ -784,6 +802,54 @@ has a side effect on your data. For more, see `Safe methods`_ in the HTTP spec.
.. _Safe methods: http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.1.1
+``update_or_create(**kwargs)``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+**New in Django development version**
+
+A convenience method for looking up an object with the given kwargs, and then
+either updating the values of the object if one is found or creating an
+object if one was not found.
+
+This method calls ``get_or_create()`` behind the scenes, and similarly
+returns a tuple of ``(object, created)``, where``object`` is the updated or
+created object and ``created`` is a boolean specifying whether a new object
+was created.
+
+This is meant as a shortcut to the following type of code::
+
+ obj, created = Person.objects.get_or_create(first_name='John', last_name='Lennon',
+ defaults={'birthday': date(1940, 10, 9)})
+ if not created:
+ obj.update('birthday'=date(1940, 10, 9))
+
+This pattern gets quite unwieldy as the number of fields in a model goes up.
+The above example can be rewritten using ``update_or_create()`` like so::
+
+ obj, created = Person.objects.update_or_create(first_name='John', last_name='Lennon',
+ defaults={'birthday': date(1940, 10, 9)})
+
+Any keyword arguments passed to ``update_or_create()`` will be used in a
+call to ``get_or_create()``. If ``get_or_create()`` creates an object, then
+nothing needs to be done by ``update_or_create()`` and a tuple of the created
+object and ``True`` is returned. If, on the other hand, ``get_or_create()``
+does not create a new object, then ``update_or_create()`` will update the
+object with the values passed in the ``defaults`` parameter and a tuple of
+the updated object and ``True`` is returned.
+
+The ``defaults`` parameter should be a dict of attribute-value pairs that
+you want to update. If ``defaults`` is empty or not specified, then
+``update_or_create()`` will act exactly like ``get_or_create()`` since there
+would be nothing to update.
+
+As with ``get_or_create()``, if you need to use ``update_or_create()`` in a
+view, please make sure to use it only in ``POST`` requests unless you have a
+good reason not to. ``GET`` requests shouldn't have any effect on data; use
+``POST`` whenever a request to a page has a side effect on your data. For
+more, see `Safe methods`_ in the HTTP spec.
+
+.. _Safe methods: http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.1.1
+
``count()``
~~~~~~~~~~~
View
6 docs/settings.txt
@@ -157,13 +157,13 @@ ABSOLUTE_URL_OVERRIDES
Default: ``{}`` (Empty dictionary)
-A dictionary mapping ``"app_label.module_name"`` strings to functions that take
+A dictionary mapping ``"app_label.model_name"`` strings to functions that take
a model object and return its URL. This is a way of overriding
``get_absolute_url()`` methods on a per-installation basis. Example::
ABSOLUTE_URL_OVERRIDES = {
- 'blogs.blogs': lambda o: "/blogs/%s/" % o.slug,
- 'news.stories': lambda o: "/stories/%s/%s/" % (o.pub_year, o.slug),
+ 'blogs.Weblog': lambda o: "/blogs/%s/" % o.slug,
+ 'news.Story': lambda o: "/stories/%s/%s/" % (o.pub_year, o.slug),
}
ADMIN_FOR
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