Documented QuerySet.datetimes and updated QuerySet.dates.

This commit is contained in:
Aymeric Augustin 2013-02-10 16:15:49 +01:00
parent ac4faa6dc3
commit 29413eab2b
2 changed files with 75 additions and 14 deletions

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@ -550,14 +550,19 @@ dates
.. method:: dates(field, kind, order='ASC')
Returns a ``DateQuerySet`` — a ``QuerySet`` that evaluates to a list of
``datetime.datetime`` objects representing all available dates of a particular
kind within the contents of the ``QuerySet``.
:class:`datetime.date` objects representing all available dates of a
particular kind within the contents of the ``QuerySet``.
``field`` should be the name of a ``DateField`` or ``DateTimeField`` of your
model.
.. versionchanged:: 1.6
``dates`` used to return a list of :class:`datetime.datetime` objects.
``field`` should be the name of a ``DateField`` of your model.
.. versionchanged:: 1.6
``dates`` used to accept operating on a ``DateTimeField``.
``kind`` should be either ``"year"``, ``"month"`` or ``"day"``. Each
``datetime.datetime`` object in the result list is "truncated" to the given
``datetime.date`` object in the result list is "truncated" to the given
``type``.
* ``"year"`` returns a list of all distinct year values for the field.
@ -572,21 +577,58 @@ model.
Examples::
>>> Entry.objects.dates('pub_date', 'year')
[datetime.datetime(2005, 1, 1)]
[datetime.date(2005, 1, 1)]
>>> Entry.objects.dates('pub_date', 'month')
[datetime.datetime(2005, 2, 1), datetime.datetime(2005, 3, 1)]
[datetime.date(2005, 2, 1), datetime.date(2005, 3, 1)]
>>> Entry.objects.dates('pub_date', 'day')
[datetime.datetime(2005, 2, 20), datetime.datetime(2005, 3, 20)]
[datetime.date(2005, 2, 20), datetime.date(2005, 3, 20)]
>>> Entry.objects.dates('pub_date', 'day', order='DESC')
[datetime.datetime(2005, 3, 20), datetime.datetime(2005, 2, 20)]
[datetime.date(2005, 3, 20), datetime.date(2005, 2, 20)]
>>> Entry.objects.filter(headline__contains='Lennon').dates('pub_date', 'day')
[datetime.datetime(2005, 3, 20)]
[datetime.date(2005, 3, 20)]
.. warning::
datetimes
~~~~~~~~~
When :doc:`time zone support </topics/i18n/timezones>` is enabled, Django
uses UTC in the database connection, which means the aggregation is
performed in UTC. This is a known limitation of the current implementation.
.. versionadded:: 1.6
.. method:: datetimes(field, kind, order='ASC', tzinfo=None)
Returns a ``DateTimeQuerySet`` — a ``QuerySet`` that evaluates to a list of
:class:`datetime.datetime` objects representing all available dates of a
particular kind within the contents of the ``QuerySet``.
``field`` should be the name of a ``DateTimeField`` of your model.
``kind`` should be either ``"year"``, ``"month"``, ``"day"``, ``"hour"``,
``"minute"`` or ``"second"``. Each ``datetime.datetime`` object in the result
list is "truncated" to the given ``type``.
``order``, which defaults to ``'ASC'``, should be either ``'ASC'`` or
``'DESC'``. This specifies how to order the results.
``tzinfo`` defines the time zone to which datetimes are converted prior to
truncation. Indeed, a given datetime has different representations depending
on the time zone in use. This parameter must be a :class:`datetime.tzinfo`
object. If it's ``None``, Django uses the :ref:`current time zone
<default-current-time-zone>`. It has no effect when :setting:`USE_TZ` is
``False``.
.. note::
This function performs time zone conversions directly in the database.
As a consequence, your database must be able to interpret the value of
``tzinfo.tzname(None)``. This translates into the following requirements:
- SQLite: install pytz_ — conversions are actually performed in Python.
- PostgreSQL: no requirements (see `Time Zones`_).
- Oracle: no requirements (see `Choosing a Time Zone File`_).
- MySQL: load the time zone tables with `mysql_tzinfo_to_sql`_.
.. _pytz: http://pytz.sourceforge.net/
.. _Time Zones: http://www.postgresql.org/docs/9.2/static/datatype-datetime.html#DATATYPE-TIMEZONES
.. _Choosing a Time Zone File: http://docs.oracle.com/cd/B19306_01/server.102/b14225/ch4datetime.htm#i1006667
.. _mysql_tzinfo_to_sql: http://dev.mysql.com/doc/refman/5.5/en/mysql-tzinfo-to-sql.html
none
~~~~

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@ -30,6 +30,16 @@ prevention <clickjacking-prevention>` are turned on.
If the default templates don't suit your tastes, you can use :ref:`custom
project and app templates <custom-app-and-project-templates>`.
Time zone aware aggregation
~~~~~~~~~~~~~~~~~~~~~~~~~~~
The support for :doc:`time zones </topics/i18n/timezones>` introduced in
Django 1.4 didn't work well with :meth:`QuerySet.dates()
<django.db.models.query.QuerySet.dates>`: aggregation was always performed in
UTC. This limitation was lifted in Django 1.6. Use :meth:`QuerySet.datetimes()
<django.db.models.query.QuerySet.datetimes>` to perform time zone aware
aggregation on a :class:`~django.db.models.DateTimeField`.
Minor features
~~~~~~~~~~~~~~
@ -80,6 +90,15 @@ Backwards incompatible changes in 1.6
:meth:`~django.db.models.query.QuerySet.none` has been called:
``isinstance(qs.none(), EmptyQuerySet)``
* :meth:`QuerySet.dates() <django.db.models.query.QuerySet.dates>` raises an
error if it's used on :class:`~django.db.models.DateTimeField` when time
zone support is active. Use :meth:`QuerySet.datetimes()
<django.db.models.query.QuerySet.datetimes>` instead.
* :meth:`QuerySet.dates() <django.db.models.query.QuerySet.dates>` returns a
list of :class:`~datetime.date`. It used to return a list of
:class:`~datetime.datetime`.
* If your CSS/Javascript code used to access HTML input widgets by type, you
should review it as ``type='text'`` widgets might be now output as
``type='email'`` or ``type='url'`` depending on their corresponding field type.