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Minor edits to docs/topics/db/queries.txt.

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Cody Scott 2013-10-11 12:45:00 -04:00 committed by Tim Graham
parent 848101bf17
commit 8bfc7cc64c
1 changed files with 9 additions and 8 deletions
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docs/topics/db/queries.txt
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@ -140,8 +140,8 @@ To retrieve objects from your database, construct a
:class:`~django.db.models.Manager` on your model class. :class:`~django.db.models.Manager` on your model class.
A :class:`~django.db.models.query.QuerySet` represents a collection of objects A :class:`~django.db.models.query.QuerySet` represents a collection of objects
from your database. It can have zero, one or many *filters* -- criteria that from your database. It can have zero, one or many *filters*. Filters narrow
narrow down the collection based on given parameters. In SQL terms, a down the query results based on the given parameters. In SQL terms, a
:class:`~django.db.models.query.QuerySet` equates to a ``SELECT`` statement, :class:`~django.db.models.query.QuerySet` equates to a ``SELECT`` statement,
and a filter is a limiting clause such as ``WHERE`` or ``LIMIT``. and a filter is a limiting clause such as ``WHERE`` or ``LIMIT``.
@ -257,10 +257,10 @@ Example::
These three ``QuerySets`` are separate. The first is a base These three ``QuerySets`` are separate. The first is a base
:class:`~django.db.models.query.QuerySet` containing all entries that contain a :class:`~django.db.models.query.QuerySet` containing all entries that contain a
headline starting with "What". The second is a subset of the first, with an headline starting with "What". The second is a subset of the first, with an
additional criteria that excludes records whose ``pub_date`` is greater than additional criteria that excludes records whose ``pub_date`` is today or in the
now. The third is a subset of the first, with an additional criteria that future. The third is a subset of the first, with an additional criteria that
selects only the records whose ``pub_date`` is greater than now. The initial selects only the records whose ``pub_date`` is today or in the future. The
:class:`~django.db.models.query.QuerySet` (``q1``) is unaffected by the initial :class:`~django.db.models.query.QuerySet` (``q1``) is unaffected by the
refinement process. refinement process.
.. _querysets-are-lazy: .. _querysets-are-lazy:
@ -1079,8 +1079,9 @@ the foreign key aren't saved to the database until you call
>>> e.blog = some_blog >>> e.blog = some_blog
>>> e.save() >>> e.save()
If a :class:`~django.db.models.ForeignKey` field has ``null=True`` set (i.e., it allows ``NULL`` If a :class:`~django.db.models.ForeignKey` field has ``null=True`` set (i.e.,
values), you can assign ``None`` to it. Example:: it allows ``NULL`` values), you can assign ``None`` to remove the relation.
Example::
>>> e = Entry.objects.get(id=2) >>> e = Entry.objects.get(id=2)
>>> e.blog = None >>> e.blog = None