mirror of
https://github.com/django/django.git
synced 2024-12-27 03:25:58 +00:00
ff60c5f9de
This monster of a patch is the result of Alex Gaynor's 2009 Google Summer of Code project. Congratulations to Alex for a job well done. Big thanks also go to: * Justin Bronn for keeping GIS in line with the changes, * Karen Tracey and Jani Tiainen for their help testing Oracle support * Brett Hoerner, Jon Loyens, and Craig Kimmerer for their feedback. * Malcolm Treddinick for his guidance during the GSoC submission process. * Simon Willison for driving the original design process * Cal Henderson for complaining about ponies he wanted. ... and everyone else too numerous to mention that helped to bring this feature into fruition. git-svn-id: http://code.djangoproject.com/svn/django/trunk@11952 bcc190cf-cafb-0310-a4f2-bffc1f526a37
441 lines
15 KiB
Python
441 lines
15 KiB
Python
# coding: utf-8
|
|
"""
|
|
1. Bare-bones model
|
|
|
|
This is a basic model with only two non-primary-key fields.
|
|
"""
|
|
# Python 2.3 doesn't have set as a builtin
|
|
try:
|
|
set
|
|
except NameError:
|
|
from sets import Set as set
|
|
|
|
# Python 2.3 doesn't have sorted()
|
|
try:
|
|
sorted
|
|
except NameError:
|
|
from django.utils.itercompat import sorted
|
|
|
|
from django.db import models, DEFAULT_DB_ALIAS
|
|
|
|
class Article(models.Model):
|
|
headline = models.CharField(max_length=100, default='Default headline')
|
|
pub_date = models.DateTimeField()
|
|
|
|
class Meta:
|
|
ordering = ('pub_date','headline')
|
|
|
|
def __unicode__(self):
|
|
return self.headline
|
|
|
|
__test__ = {'API_TESTS': """
|
|
# No articles are in the system yet.
|
|
>>> Article.objects.all()
|
|
[]
|
|
|
|
# Create an Article.
|
|
>>> from datetime import datetime
|
|
>>> a = Article(id=None, headline='Area man programs in Python', pub_date=datetime(2005, 7, 28))
|
|
|
|
# Save it into the database. You have to call save() explicitly.
|
|
>>> a.save()
|
|
|
|
# Now it has an ID. Note it's a long integer, as designated by the trailing "L".
|
|
>>> a.id
|
|
1L
|
|
|
|
# Models have a pk property that is an alias for the primary key attribute (by
|
|
# default, the 'id' attribute).
|
|
>>> a.pk
|
|
1L
|
|
|
|
# Access database columns via Python attributes.
|
|
>>> a.headline
|
|
'Area man programs in Python'
|
|
>>> a.pub_date
|
|
datetime.datetime(2005, 7, 28, 0, 0)
|
|
|
|
# Change values by changing the attributes, then calling save().
|
|
>>> a.headline = 'Area woman programs in Python'
|
|
>>> a.save()
|
|
|
|
# Article.objects.all() returns all the articles in the database.
|
|
>>> Article.objects.all()
|
|
[<Article: Area woman programs in Python>]
|
|
|
|
# Django provides a rich database lookup API.
|
|
>>> Article.objects.get(id__exact=1)
|
|
<Article: Area woman programs in Python>
|
|
>>> Article.objects.get(headline__startswith='Area woman')
|
|
<Article: Area woman programs in Python>
|
|
>>> Article.objects.get(pub_date__year=2005)
|
|
<Article: Area woman programs in Python>
|
|
>>> Article.objects.get(pub_date__year=2005, pub_date__month=7)
|
|
<Article: Area woman programs in Python>
|
|
>>> Article.objects.get(pub_date__year=2005, pub_date__month=7, pub_date__day=28)
|
|
<Article: Area woman programs in Python>
|
|
>>> Article.objects.get(pub_date__week_day=5)
|
|
<Article: Area woman programs in Python>
|
|
|
|
# The "__exact" lookup type can be omitted, as a shortcut.
|
|
>>> Article.objects.get(id=1)
|
|
<Article: Area woman programs in Python>
|
|
>>> Article.objects.get(headline='Area woman programs in Python')
|
|
<Article: Area woman programs in Python>
|
|
|
|
>>> Article.objects.filter(pub_date__year=2005)
|
|
[<Article: Area woman programs in Python>]
|
|
>>> Article.objects.filter(pub_date__year=2004)
|
|
[]
|
|
>>> Article.objects.filter(pub_date__year=2005, pub_date__month=7)
|
|
[<Article: Area woman programs in Python>]
|
|
|
|
>>> Article.objects.filter(pub_date__week_day=5)
|
|
[<Article: Area woman programs in Python>]
|
|
>>> Article.objects.filter(pub_date__week_day=6)
|
|
[]
|
|
|
|
# Django raises an Article.DoesNotExist exception for get() if the parameters
|
|
# don't match any object.
|
|
>>> Article.objects.get(id__exact=2)
|
|
Traceback (most recent call last):
|
|
...
|
|
DoesNotExist: Article matching query does not exist.
|
|
|
|
>>> Article.objects.get(pub_date__year=2005, pub_date__month=8)
|
|
Traceback (most recent call last):
|
|
...
|
|
DoesNotExist: Article matching query does not exist.
|
|
|
|
>>> Article.objects.get(pub_date__week_day=6)
|
|
Traceback (most recent call last):
|
|
...
|
|
DoesNotExist: Article matching query does not exist.
|
|
|
|
# Lookup by a primary key is the most common case, so Django provides a
|
|
# shortcut for primary-key exact lookups.
|
|
# The following is identical to articles.get(id=1).
|
|
>>> Article.objects.get(pk=1)
|
|
<Article: Area woman programs in Python>
|
|
|
|
# pk can be used as a shortcut for the primary key name in any query
|
|
>>> Article.objects.filter(pk__in=[1])
|
|
[<Article: Area woman programs in Python>]
|
|
|
|
# Model instances of the same type and same ID are considered equal.
|
|
>>> a = Article.objects.get(pk=1)
|
|
>>> b = Article.objects.get(pk=1)
|
|
>>> a == b
|
|
True
|
|
|
|
# You can initialize a model instance using positional arguments, which should
|
|
# match the field order as defined in the model.
|
|
>>> a2 = Article(None, 'Second article', datetime(2005, 7, 29))
|
|
>>> a2.save()
|
|
>>> a2.id
|
|
2L
|
|
>>> a2.headline
|
|
'Second article'
|
|
>>> a2.pub_date
|
|
datetime.datetime(2005, 7, 29, 0, 0)
|
|
|
|
# ...or, you can use keyword arguments.
|
|
>>> a3 = Article(id=None, headline='Third article', pub_date=datetime(2005, 7, 30))
|
|
>>> a3.save()
|
|
>>> a3.id
|
|
3L
|
|
>>> a3.headline
|
|
'Third article'
|
|
>>> a3.pub_date
|
|
datetime.datetime(2005, 7, 30, 0, 0)
|
|
|
|
# You can also mix and match position and keyword arguments, but be sure not to
|
|
# duplicate field information.
|
|
>>> a4 = Article(None, 'Fourth article', pub_date=datetime(2005, 7, 31))
|
|
>>> a4.save()
|
|
>>> a4.headline
|
|
'Fourth article'
|
|
|
|
# Don't use invalid keyword arguments.
|
|
>>> a5 = Article(id=None, headline='Invalid', pub_date=datetime(2005, 7, 31), foo='bar')
|
|
Traceback (most recent call last):
|
|
...
|
|
TypeError: 'foo' is an invalid keyword argument for this function
|
|
|
|
# You can leave off the value for an AutoField when creating an object, because
|
|
# it'll get filled in automatically when you save().
|
|
>>> a5 = Article(headline='Article 6', pub_date=datetime(2005, 7, 31))
|
|
>>> a5.save()
|
|
>>> a5.id
|
|
5L
|
|
>>> a5.headline
|
|
'Article 6'
|
|
|
|
# If you leave off a field with "default" set, Django will use the default.
|
|
>>> a6 = Article(pub_date=datetime(2005, 7, 31))
|
|
>>> a6.save()
|
|
>>> a6.headline
|
|
u'Default headline'
|
|
|
|
# For DateTimeFields, Django saves as much precision (in seconds) as you
|
|
# give it.
|
|
>>> a7 = Article(headline='Article 7', pub_date=datetime(2005, 7, 31, 12, 30))
|
|
>>> a7.save()
|
|
>>> Article.objects.get(id__exact=7).pub_date
|
|
datetime.datetime(2005, 7, 31, 12, 30)
|
|
|
|
>>> a8 = Article(headline='Article 8', pub_date=datetime(2005, 7, 31, 12, 30, 45))
|
|
>>> a8.save()
|
|
>>> Article.objects.get(id__exact=8).pub_date
|
|
datetime.datetime(2005, 7, 31, 12, 30, 45)
|
|
>>> a8.id
|
|
8L
|
|
|
|
# Saving an object again doesn't create a new object -- it just saves the old one.
|
|
>>> a8.save()
|
|
>>> a8.id
|
|
8L
|
|
>>> a8.headline = 'Updated article 8'
|
|
>>> a8.save()
|
|
>>> a8.id
|
|
8L
|
|
|
|
>>> a7 == a8
|
|
False
|
|
>>> a8 == Article.objects.get(id__exact=8)
|
|
True
|
|
>>> a7 != a8
|
|
True
|
|
>>> Article.objects.get(id__exact=8) != Article.objects.get(id__exact=7)
|
|
True
|
|
>>> Article.objects.get(id__exact=8) == Article.objects.get(id__exact=7)
|
|
False
|
|
|
|
# You can use 'in' to test for membership...
|
|
>>> a8 in Article.objects.all()
|
|
True
|
|
|
|
# ... but there will often be more efficient ways if that is all you need:
|
|
>>> Article.objects.filter(id=a8.id).exists()
|
|
True
|
|
|
|
# dates() returns a list of available dates of the given scope for the given field.
|
|
>>> Article.objects.dates('pub_date', 'year')
|
|
[datetime.datetime(2005, 1, 1, 0, 0)]
|
|
>>> Article.objects.dates('pub_date', 'month')
|
|
[datetime.datetime(2005, 7, 1, 0, 0)]
|
|
>>> Article.objects.dates('pub_date', 'day')
|
|
[datetime.datetime(2005, 7, 28, 0, 0), datetime.datetime(2005, 7, 29, 0, 0), datetime.datetime(2005, 7, 30, 0, 0), datetime.datetime(2005, 7, 31, 0, 0)]
|
|
>>> Article.objects.dates('pub_date', 'day', order='ASC')
|
|
[datetime.datetime(2005, 7, 28, 0, 0), datetime.datetime(2005, 7, 29, 0, 0), datetime.datetime(2005, 7, 30, 0, 0), datetime.datetime(2005, 7, 31, 0, 0)]
|
|
>>> Article.objects.dates('pub_date', 'day', order='DESC')
|
|
[datetime.datetime(2005, 7, 31, 0, 0), datetime.datetime(2005, 7, 30, 0, 0), datetime.datetime(2005, 7, 29, 0, 0), datetime.datetime(2005, 7, 28, 0, 0)]
|
|
|
|
# dates() requires valid arguments.
|
|
|
|
>>> Article.objects.dates()
|
|
Traceback (most recent call last):
|
|
...
|
|
TypeError: dates() takes at least 3 arguments (1 given)
|
|
|
|
>>> Article.objects.dates('invalid_field', 'year')
|
|
Traceback (most recent call last):
|
|
...
|
|
FieldDoesNotExist: Article has no field named 'invalid_field'
|
|
|
|
>>> Article.objects.dates('pub_date', 'bad_kind')
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: 'kind' must be one of 'year', 'month' or 'day'.
|
|
|
|
>>> Article.objects.dates('pub_date', 'year', order='bad order')
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: 'order' must be either 'ASC' or 'DESC'.
|
|
|
|
# Use iterator() with dates() to return a generator that lazily requests each
|
|
# result one at a time, to save memory.
|
|
>>> for a in Article.objects.dates('pub_date', 'day', order='DESC').iterator():
|
|
... print repr(a)
|
|
datetime.datetime(2005, 7, 31, 0, 0)
|
|
datetime.datetime(2005, 7, 30, 0, 0)
|
|
datetime.datetime(2005, 7, 29, 0, 0)
|
|
datetime.datetime(2005, 7, 28, 0, 0)
|
|
|
|
# You can combine queries with & and |.
|
|
>>> s1 = Article.objects.filter(id__exact=1)
|
|
>>> s2 = Article.objects.filter(id__exact=2)
|
|
>>> s1 | s2
|
|
[<Article: Area woman programs in Python>, <Article: Second article>]
|
|
>>> s1 & s2
|
|
[]
|
|
|
|
# You can get the number of objects like this:
|
|
>>> len(Article.objects.filter(id__exact=1))
|
|
1
|
|
|
|
# You can get items using index and slice notation.
|
|
>>> Article.objects.all()[0]
|
|
<Article: Area woman programs in Python>
|
|
>>> Article.objects.all()[1:3]
|
|
[<Article: Second article>, <Article: Third article>]
|
|
>>> s3 = Article.objects.filter(id__exact=3)
|
|
>>> (s1 | s2 | s3)[::2]
|
|
[<Article: Area woman programs in Python>, <Article: Third article>]
|
|
|
|
# Slicing works with longs.
|
|
>>> Article.objects.all()[0L]
|
|
<Article: Area woman programs in Python>
|
|
>>> Article.objects.all()[1L:3L]
|
|
[<Article: Second article>, <Article: Third article>]
|
|
>>> s3 = Article.objects.filter(id__exact=3)
|
|
>>> (s1 | s2 | s3)[::2L]
|
|
[<Article: Area woman programs in Python>, <Article: Third article>]
|
|
|
|
# And can be mixed with ints.
|
|
>>> Article.objects.all()[1:3L]
|
|
[<Article: Second article>, <Article: Third article>]
|
|
|
|
# Slices (without step) are lazy:
|
|
>>> Article.objects.all()[0:5].filter()
|
|
[<Article: Area woman programs in Python>, <Article: Second article>, <Article: Third article>, <Article: Article 6>, <Article: Default headline>]
|
|
|
|
# Slicing again works:
|
|
>>> Article.objects.all()[0:5][0:2]
|
|
[<Article: Area woman programs in Python>, <Article: Second article>]
|
|
>>> Article.objects.all()[0:5][:2]
|
|
[<Article: Area woman programs in Python>, <Article: Second article>]
|
|
>>> Article.objects.all()[0:5][4:]
|
|
[<Article: Default headline>]
|
|
>>> Article.objects.all()[0:5][5:]
|
|
[]
|
|
|
|
# Some more tests!
|
|
>>> Article.objects.all()[2:][0:2]
|
|
[<Article: Third article>, <Article: Article 6>]
|
|
>>> Article.objects.all()[2:][:2]
|
|
[<Article: Third article>, <Article: Article 6>]
|
|
>>> Article.objects.all()[2:][2:3]
|
|
[<Article: Default headline>]
|
|
|
|
# Using an offset without a limit is also possible.
|
|
>>> Article.objects.all()[5:]
|
|
[<Article: Fourth article>, <Article: Article 7>, <Article: Updated article 8>]
|
|
|
|
# Also, once you have sliced you can't filter, re-order or combine
|
|
>>> Article.objects.all()[0:5].filter(id=1)
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: Cannot filter a query once a slice has been taken.
|
|
|
|
>>> Article.objects.all()[0:5].order_by('id')
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: Cannot reorder a query once a slice has been taken.
|
|
|
|
>>> Article.objects.all()[0:1] & Article.objects.all()[4:5]
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: Cannot combine queries once a slice has been taken.
|
|
|
|
# Negative slices are not supported, due to database constraints.
|
|
# (hint: inverting your ordering might do what you need).
|
|
>>> Article.objects.all()[-1]
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: Negative indexing is not supported.
|
|
>>> Article.objects.all()[0:-5]
|
|
Traceback (most recent call last):
|
|
...
|
|
AssertionError: Negative indexing is not supported.
|
|
|
|
# An Article instance doesn't have access to the "objects" attribute.
|
|
# That's only available on the class.
|
|
>>> a7.objects.all()
|
|
Traceback (most recent call last):
|
|
...
|
|
AttributeError: Manager isn't accessible via Article instances
|
|
|
|
>>> a7.objects
|
|
Traceback (most recent call last):
|
|
...
|
|
AttributeError: Manager isn't accessible via Article instances
|
|
|
|
# Bulk delete test: How many objects before and after the delete?
|
|
>>> Article.objects.all()
|
|
[<Article: Area woman programs in Python>, <Article: Second article>, <Article: Third article>, <Article: Article 6>, <Article: Default headline>, <Article: Fourth article>, <Article: Article 7>, <Article: Updated article 8>]
|
|
>>> Article.objects.filter(id__lte=4).delete()
|
|
>>> Article.objects.all()
|
|
[<Article: Article 6>, <Article: Default headline>, <Article: Article 7>, <Article: Updated article 8>]
|
|
"""}
|
|
|
|
from django.conf import settings
|
|
|
|
building_docs = getattr(settings, 'BUILDING_DOCS', False)
|
|
|
|
if building_docs or settings.DATABASES[DEFAULT_DB_ALIAS]['ENGINE'] == 'django.db.backends.postgresql':
|
|
__test__['API_TESTS'] += """
|
|
# In PostgreSQL, microsecond-level precision is available.
|
|
>>> a9 = Article(headline='Article 9', pub_date=datetime(2005, 7, 31, 12, 30, 45, 180))
|
|
>>> a9.save()
|
|
>>> Article.objects.get(id__exact=9).pub_date
|
|
datetime.datetime(2005, 7, 31, 12, 30, 45, 180)
|
|
"""
|
|
|
|
if building_docs or settings.DATABASES[DEFAULT_DB_ALIAS]['ENGINE'] == 'django.db.backends.mysql':
|
|
__test__['API_TESTS'] += """
|
|
# In MySQL, microsecond-level precision isn't available. You'll lose
|
|
# microsecond-level precision once the data is saved.
|
|
>>> a9 = Article(headline='Article 9', pub_date=datetime(2005, 7, 31, 12, 30, 45, 180))
|
|
>>> a9.save()
|
|
>>> Article.objects.get(id__exact=9).pub_date
|
|
datetime.datetime(2005, 7, 31, 12, 30, 45)
|
|
"""
|
|
|
|
__test__['API_TESTS'] += """
|
|
|
|
# You can manually specify the primary key when creating a new object.
|
|
>>> a101 = Article(id=101, headline='Article 101', pub_date=datetime(2005, 7, 31, 12, 30, 45))
|
|
>>> a101.save()
|
|
>>> a101 = Article.objects.get(pk=101)
|
|
>>> a101.headline
|
|
u'Article 101'
|
|
|
|
# You can create saved objects in a single step
|
|
>>> a10 = Article.objects.create(headline="Article 10", pub_date=datetime(2005, 7, 31, 12, 30, 45))
|
|
>>> Article.objects.get(headline="Article 10")
|
|
<Article: Article 10>
|
|
|
|
# Edge-case test: A year lookup should retrieve all objects in the given
|
|
year, including Jan. 1 and Dec. 31.
|
|
>>> a11 = Article.objects.create(headline='Article 11', pub_date=datetime(2008, 1, 1))
|
|
>>> a12 = Article.objects.create(headline='Article 12', pub_date=datetime(2008, 12, 31, 23, 59, 59, 999999))
|
|
>>> Article.objects.filter(pub_date__year=2008)
|
|
[<Article: Article 11>, <Article: Article 12>]
|
|
|
|
# Unicode data works, too.
|
|
>>> a = Article(headline=u'\u6797\u539f \u3081\u3050\u307f', pub_date=datetime(2005, 7, 28))
|
|
>>> a.save()
|
|
>>> Article.objects.get(pk=a.id).headline
|
|
u'\u6797\u539f \u3081\u3050\u307f'
|
|
|
|
# Model instances have a hash function, so they can be used in sets or as
|
|
# dictionary keys. Two models compare as equal if their primary keys are equal.
|
|
>>> s = set([a10, a11, a12])
|
|
>>> Article.objects.get(headline='Article 11') in s
|
|
True
|
|
|
|
# The 'select' argument to extra() supports names with dashes in them, as long
|
|
# as you use values().
|
|
>>> dicts = Article.objects.filter(pub_date__year=2008).extra(select={'dashed-value': '1'}).values('headline', 'dashed-value')
|
|
>>> [sorted(d.items()) for d in dicts]
|
|
[[('dashed-value', 1), ('headline', u'Article 11')], [('dashed-value', 1), ('headline', u'Article 12')]]
|
|
|
|
# If you use 'select' with extra() and names containing dashes on a query
|
|
# that's *not* a values() query, those extra 'select' values will silently be
|
|
# ignored.
|
|
>>> articles = Article.objects.filter(pub_date__year=2008).extra(select={'dashed-value': '1', 'undashedvalue': '2'})
|
|
>>> articles[0].undashedvalue
|
|
2
|
|
"""
|