"""

1. Bare-bones model

This is a basic model with only two non-primary-key fields.

"""

from django.db import models

class Article(models.Model):

    headline = models.CharField(maxlength=100, default='Default headline')

    pub_date = models.DateTimeField()

    class Meta:

        ordering = ('pub_date','headline')

    def __str__(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

# 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>

# 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>]

# 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.

# 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

'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

# 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>]

# 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>]

# Note that you can't use 'offset' without 'limit' (on some dbs), so this doesn't work:

>>> Article.objects.all()[2:]

Traceback (most recent call last):

    ...

AssertionError: 'offset' is not allowed without 'limit'

# 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.DATABASE_ENGINE == '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.DATABASE_ENGINE == '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

'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>]

"""