Ticket #14004: 14004.2.diff

docs/ref/models/querysets.txt

@@ -1221 +1221 @@
 more overall work (an additional query) than simply using
 ``bool(some_query_set)``.
 
+``update()``
+~~~~~~~~~~~~
+
+.. method:: update()
+
+Returns the number of rows affected by a SQL update query. The ``update()``
+method is applied instantly and the only restriction on the :class:`QuerySet`
+that is updated is that it can only access one database table, the model's main
+table. You can filter based on related fields, but you can only update columns
+in the model's main table.
+
+For example, if you wanted to update all blog entries to use the same headline::
+
+    >>> b = Blog.objects.get(pk=1)
+
+    # Update all the headlines belonging to this Blog.
+    >>> Entry.objects.select_related().filter(blog=b).update(headline='Everything is the same')
+
+The ``update()`` method does bulk updates and does not call any ``save()``
+methods on your models, or emit the ``pre_save`` or ``post_save`` signals
+(which are a consequence of calling ``save()``).
+
 .. _field-lookups:
 
 Field lookups