mirrors/django
1
0
Fork 0
mirror of https://github.com/django/django.git synced 2025-08-04 19:08:28 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 4

Fixed #5768 -- Added support for ManyToManyFields and reverse relations in values() and values_list(). Thanks to mrmachine for the patch.

Browse source 
git-svn-id: http://code.djangoproject.com/svn/django/trunk@14655 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Carl Meyer 2010-11-21 02:28:25 +00:00
parent 7592d68541
commit 9b432cb67b
4 changed files with 110 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

27
docs/ref/models/querysets.txt
View file

@ -398,11 +398,8 @@ Example::
>>> Blog.objects.values('id', 'name')
[{'id': 1, 'name': 'Beatles Blog'}]
A couple of subtleties that are worth mentioning:
A few subtleties that are worth mentioning:
* The ``values()`` method does not return anything for
:class:`~django.db.models.ManyToManyField` attributes and will raise an
error if you try to pass in this type of field to it.
* If you have a field called ``foo`` that is a
:class:`~django.db.models.ForeignKey`, the default ``values()`` call
will return a dictionary key called ``foo_id``, since this is the name
@ -453,6 +450,28 @@ followed (optionally) by any output-affecting methods (such as ``values()``),
but it doesn't really matter. This is your chance to really flaunt your
individualism.
.. versionchanged:: 1.3
The ``values()`` method previously did not return anything for
:class:`~django.db.models.ManyToManyField` attributes and would raise an error
if you tried to pass this type of field to it.
This restriction has been lifted, and you can now also refer to fields on
related models with reverse relations through ``OneToOneField``, ``ForeignKey``
and ``ManyToManyField`` attributes::
Blog.objects.values('name', 'entry__headline')
[{'name': 'My blog', 'entry__headline': 'An entry'},
{'name': 'My blog', 'entry__headline': 'Another entry'}, ...]
.. warning::
Because :class:`~django.db.models.ManyToManyField` attributes and reverse
relations can have multiple related rows, including these can have a
multiplier effect on the size of your result set. This will be especially
pronounced if you include multiple such fields in your ``values()`` query,
in which case all possible combinations will be returned.
``values_list(*fields)``
~~~~~~~~~~~~~~~~~~~~~~~~