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Add missing imports and models to the examples in the the model layer…

… documentation
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commit e4591debd19361e628317e936ed8123d9897dd6a 1 parent d5ce2ff
@frog32 frog32 authored
View
10 docs/ref/models/fields.txt
@@ -97,6 +97,8 @@ second element is the human-readable name. For example::
Generally, it's best to define choices inside a model class, and to
define a suitably-named constant for each value::
+ from django.db import models
+
class Student(models.Model):
FRESHMAN = 'FR'
SOPHOMORE = 'SO'
@@ -994,12 +996,15 @@ relationship with itself -- use ``models.ForeignKey('self')``.
If you need to create a relationship on a model that has not yet been defined,
you can use the name of the model, rather than the model object itself::
+ from django.db import models
+
class Car(models.Model):
manufacturer = models.ForeignKey('Manufacturer')
# ...
class Manufacturer(models.Model):
# ...
+ pass
To refer to models defined in another application, you can explicitly specify
a model with the full application label. For example, if the ``Manufacturer``
@@ -1132,6 +1137,9 @@ The possible values for :attr:`~ForeignKey.on_delete` are found in
necessary to avoid executing queries at the time your models.py is
imported::
+ from django.db import models
+ from django.contrib.auth.models import User
+
def get_sentinel_user():
return User.objects.get_or_create(username='deleted')[0]
@@ -1204,6 +1212,8 @@ that control how the relationship functions.
Only used in the definition of ManyToManyFields on self. Consider the
following model::
+ from django.db import models
+
class Person(models.Model):
friends = models.ManyToManyField("self")
View
10 docs/ref/models/instances.txt
@@ -34,6 +34,8 @@ that, you need to :meth:`~Model.save()`.
1. Add a classmethod on the model class::
+ from django.db import models
+
class Book(models.Model):
title = models.CharField(max_length=100)
@@ -105,6 +107,7 @@ individually.
You'll need to call ``full_clean`` manually when you want to run one-step model
validation for your own manually created models. For example::
+ from django.core.exceptions import ValidationError
try:
article.full_clean()
except ValidationError as e:
@@ -132,6 +135,7 @@ automatically provide a value for a field, or to do validation that requires
access to more than a single field::
def clean(self):
+ import datetime
from django.core.exceptions import ValidationError
# Don't allow draft entries to have a pub_date.
if self.status == 'draft' and self.pub_date is not None:
@@ -434,6 +438,8 @@ representation of the model from the ``__unicode__()`` method.
For example::
+ from django.db import models
+
class Person(models.Model):
first_name = models.CharField(max_length=50)
last_name = models.CharField(max_length=50)
@@ -460,6 +466,9 @@ Thus, you should return a nice, human-readable string for the object's
The previous :meth:`~Model.__unicode__()` example could be similarly written
using ``__str__()`` like this::
+ from django.db import models
+ from django.utils.encoding import force_bytes
+
class Person(models.Model):
first_name = models.CharField(max_length=50)
last_name = models.CharField(max_length=50)
@@ -490,6 +499,7 @@ function is usually the best approach.)
For example::
def get_absolute_url(self):
+ from django.core.urlresolvers import reverse
return reverse('people.views.details', args=[str(self.id)])
One place Django uses ``get_absolute_url()`` is in the admin app. If an object
View
6 docs/ref/models/options.txt
@@ -145,6 +145,12 @@ Django quotes column and table names behind the scenes.
and a question has more than one answer, and the order of answers matters, you'd
do this::
+ from django.db import models
+
+ class Question(models.Model):
+ text = models.TextField()
+ # ...
+
class Answer(models.Model):
question = models.ForeignKey(Question)
# ...
View
7 docs/ref/models/querysets.txt
@@ -232,6 +232,7 @@ the model field that is being aggregated.
For example, if you were manipulating a list of blogs, you may want
to determine how many entries have been made in each blog::
+ >>> from django.db.models import Count
>>> q = Blog.objects.annotate(Count('entry'))
# The name of the first blog
>>> q[0].name
@@ -699,6 +700,8 @@ And here's ``select_related`` lookup::
``select_related()`` follows foreign keys as far as possible. If you have the
following models::
+ from django.db import models
+
class City(models.Model):
# ...
pass
@@ -814,6 +817,8 @@ that are supported by ``select_related``. It also supports prefetching of
For example, suppose you have these models::
+ from django.db import models
+
class Topping(models.Model):
name = models.CharField(max_length=30)
@@ -1565,6 +1570,7 @@ aggregated.
For example, when you are working with blog entries, you may want to know the
number of authors that have contributed blog entries::
+ >>> from django.db.models import Count
>>> q = Blog.objects.aggregate(Count('entry'))
{'entry__count': 16}
@@ -2042,6 +2048,7 @@ Range test (inclusive).
Example::
+ import datetime
start_date = datetime.date(2005, 1, 1)
end_date = datetime.date(2005, 3, 31)
Entry.objects.filter(pub_date__range=(start_date, end_date))
View
8 docs/ref/models/relations.txt
@@ -12,8 +12,11 @@ Related objects reference
* The "other side" of a :class:`~django.db.models.ForeignKey` relation.
That is::
+ from django.db import models
+
class Reporter(models.Model):
- ...
+ # ...
+ pass
class Article(models.Model):
reporter = models.ForeignKey(Reporter)
@@ -24,7 +27,8 @@ Related objects reference
* Both sides of a :class:`~django.db.models.ManyToManyField` relation::
class Topping(models.Model):
- ...
+ # ...
+ pass
class Pizza(models.Model):
toppings = models.ManyToManyField(Topping)
View
40 docs/topics/db/aggregation.txt
@@ -18,27 +18,29 @@ used to track the inventory for a series of online bookstores:
.. code-block:: python
+ from django.db import models
+
class Author(models.Model):
- name = models.CharField(max_length=100)
- age = models.IntegerField()
+ name = models.CharField(max_length=100)
+ age = models.IntegerField()
class Publisher(models.Model):
- name = models.CharField(max_length=300)
- num_awards = models.IntegerField()
+ name = models.CharField(max_length=300)
+ num_awards = models.IntegerField()
class Book(models.Model):
- name = models.CharField(max_length=300)
- pages = models.IntegerField()
- price = models.DecimalField(max_digits=10, decimal_places=2)
- rating = models.FloatField()
- authors = models.ManyToManyField(Author)
- publisher = models.ForeignKey(Publisher)
- pubdate = models.DateField()
+ name = models.CharField(max_length=300)
+ pages = models.IntegerField()
+ price = models.DecimalField(max_digits=10, decimal_places=2)
+ rating = models.FloatField()
+ authors = models.ManyToManyField(Author)
+ publisher = models.ForeignKey(Publisher)
+ pubdate = models.DateField()
class Store(models.Model):
- name = models.CharField(max_length=300)
- books = models.ManyToManyField(Book)
- registered_users = models.PositiveIntegerField()
+ name = models.CharField(max_length=300)
+ books = models.ManyToManyField(Book)
+ registered_users = models.PositiveIntegerField()
Cheat sheet
===========
@@ -123,7 +125,7 @@ If you want to generate more than one aggregate, you just add another
argument to the ``aggregate()`` clause. So, if we also wanted to know
the maximum and minimum price of all books, we would issue the query::
- >>> from django.db.models import Avg, Max, Min, Count
+ >>> from django.db.models import Avg, Max, Min
>>> Book.objects.aggregate(Avg('price'), Max('price'), Min('price'))
{'price__avg': 34.35, 'price__max': Decimal('81.20'), 'price__min': Decimal('12.99')}
@@ -148,6 +150,7 @@ the number of authors:
.. code-block:: python
# Build an annotated queryset
+ >>> from django.db.models import Count
>>> q = Book.objects.annotate(Count('authors'))
# Interrogate the first object in the queryset
>>> q[0]
@@ -192,6 +195,7 @@ and aggregate the related value.
For example, to find the price range of books offered in each store,
you could use the annotation::
+ >>> from django.db.models import Max, Min
>>> Store.objects.annotate(min_price=Min('books__price'), max_price=Max('books__price'))
This tells Django to retrieve the ``Store`` model, join (through the
@@ -222,7 +226,7 @@ For example, we can ask for all publishers, annotated with their respective
total book stock counters (note how we use ``'book'`` to specify the
``Publisher`` -> ``Book`` reverse foreign key hop)::
- >>> from django.db.models import Count, Min, Sum, Max, Avg
+ >>> from django.db.models import Count, Min, Sum, Avg
>>> Publisher.objects.annotate(Count('book'))
(Every ``Publisher`` in the resulting ``QuerySet`` will have an extra attribute
@@ -269,6 +273,7 @@ constraining the objects for which an annotation is calculated. For example,
you can generate an annotated list of all books that have a title starting
with "Django" using the query::
+ >>> from django.db.models import Count, Avg
>>> Book.objects.filter(name__startswith="Django").annotate(num_authors=Count('authors'))
When used with an ``aggregate()`` clause, a filter has the effect of
@@ -407,6 +412,8 @@ particularly, when counting things.
By way of example, suppose you have a model like this::
+ from django.db import models
+
class Item(models.Model):
name = models.CharField(max_length=10)
data = models.IntegerField()
@@ -457,5 +464,6 @@ For example, if you wanted to calculate the average number of authors per
book you first annotate the set of books with the author count, then
aggregate that author count, referencing the annotation field::
+ >>> from django.db.models import Count, Avg
>>> Book.objects.annotate(num_authors=Count('authors')).aggregate(Avg('num_authors'))
{'num_authors__avg': 1.66}
View
22 docs/topics/db/managers.txt
@@ -62,6 +62,8 @@ For example, this custom ``Manager`` offers a method ``with_counts()``, which
returns a list of all ``OpinionPoll`` objects, each with an extra
``num_responses`` attribute that is the result of an aggregate query::
+ from django.db import models
+
class PollManager(models.Manager):
def with_counts(self):
from django.db import connection
@@ -101,6 +103,8 @@ Modifying initial Manager QuerySets
A ``Manager``'s base ``QuerySet`` returns all objects in the system. For
example, using this model::
+ from django.db import models
+
class Book(models.Model):
title = models.CharField(max_length=100)
author = models.CharField(max_length=50)
@@ -236,7 +240,7 @@ class, but still customize the default manager. For example, suppose you have
this base class::
class AbstractBase(models.Model):
- ...
+ # ...
objects = CustomManager()
class Meta:
@@ -246,14 +250,15 @@ If you use this directly in a subclass, ``objects`` will be the default
manager if you declare no managers in the base class::
class ChildA(AbstractBase):
- ...
+ # ...
# This class has CustomManager as the default manager.
+ pass
If you want to inherit from ``AbstractBase``, but provide a different default
manager, you can provide the default manager on the child class::
class ChildB(AbstractBase):
- ...
+ # ...
# An explicit default manager.
default_manager = OtherManager()
@@ -274,9 +279,10 @@ it into the inheritance hierarchy *after* the defaults::
abstract = True
class ChildC(AbstractBase, ExtraManager):
- ...
+ # ...
# Default manager is CustomManager, but OtherManager is
# also available via the "extra_manager" attribute.
+ pass
Note that while you can *define* a custom manager on the abstract model, you
can't *invoke* any methods using the abstract model. That is::
@@ -349,8 +355,7 @@ the manager class::
class MyManager(models.Manager):
use_for_related_fields = True
-
- ...
+ # ...
If this attribute is set on the *default* manager for a model (only the
default manager is considered in these situations), Django will use that class
@@ -396,7 +401,8 @@ it, whereas the following will not work::
# BAD: Incorrect code
class MyManager(models.Manager):
- ...
+ # ...
+ pass
# Sets the attribute on an instance of MyManager. Django will
# ignore this setting.
@@ -404,7 +410,7 @@ it, whereas the following will not work::
mgr.use_for_related_fields = True
class MyModel(models.Model):
- ...
+ # ...
objects = mgr
# End of incorrect code.
View
50 docs/topics/db/models.txt
@@ -90,6 +90,8 @@ attributes. Be careful not to choose field names that conflict with the
Example::
+ from django.db import models
+
class Musician(models.Model):
first_name = models.CharField(max_length=50)
last_name = models.CharField(max_length=50)
@@ -290,8 +292,11 @@ For example, if a ``Car`` model has a ``Manufacturer`` -- that is, a
``Manufacturer`` makes multiple cars but each ``Car`` only has one
``Manufacturer`` -- use the following definitions::
+ from django.db import models
+
class Manufacturer(models.Model):
# ...
+ pass
class Car(models.Model):
manufacturer = models.ForeignKey(Manufacturer)
@@ -340,8 +345,11 @@ For example, if a ``Pizza`` has multiple ``Topping`` objects -- that is, a
``Topping`` can be on multiple pizzas and each ``Pizza`` has multiple toppings
-- here's how you'd represent that::
+ from django.db import models
+
class Topping(models.Model):
# ...
+ pass
class Pizza(models.Model):
# ...
@@ -403,6 +411,8 @@ intermediate model. The intermediate model is associated with the
that will act as an intermediary. For our musician example, the code would look
something like this::
+ from django.db import models
+
class Person(models.Model):
name = models.CharField(max_length=128)
@@ -583,6 +593,7 @@ It's perfectly OK to relate a model to one from another app. To do this, import
the related model at the top of the file where your model is defined. Then,
just refer to the other model class wherever needed. For example::
+ from django.db import models
from geography.models import ZipCode
class Restaurant(models.Model):
@@ -630,6 +641,8 @@ Meta options
Give your model metadata by using an inner ``class Meta``, like so::
+ from django.db import models
+
class Ox(models.Model):
horn_length = models.IntegerField()
@@ -660,6 +673,8 @@ model.
For example, this model has a few custom methods::
+ from django.db import models
+
class Person(models.Model):
first_name = models.CharField(max_length=50)
last_name = models.CharField(max_length=50)
@@ -729,6 +744,8 @@ A classic use-case for overriding the built-in methods is if you want something
to happen whenever you save an object. For example (see
:meth:`~Model.save` for documentation of the parameters it accepts)::
+ from django.db import models
+
class Blog(models.Model):
name = models.CharField(max_length=100)
tagline = models.TextField()
@@ -740,6 +757,8 @@ to happen whenever you save an object. For example (see
You can also prevent saving::
+ from django.db import models
+
class Blog(models.Model):
name = models.CharField(max_length=100)
tagline = models.TextField()
@@ -826,6 +845,8 @@ the child (and Django will raise an exception).
An example::
+ from django.db import models
+
class CommonInfo(models.Model):
name = models.CharField(max_length=100)
age = models.PositiveIntegerField()
@@ -854,14 +875,16 @@ attribute. If a child class does not declare its own :ref:`Meta <meta-options>`
class, it will inherit the parent's :ref:`Meta <meta-options>`. If the child wants to
extend the parent's :ref:`Meta <meta-options>` class, it can subclass it. For example::
+ from django.db import models
+
class CommonInfo(models.Model):
- ...
+ # ...
class Meta:
abstract = True
ordering = ['name']
class Student(CommonInfo):
- ...
+ # ...
class Meta(CommonInfo.Meta):
db_table = 'student_info'
@@ -901,6 +924,8 @@ abstract base class (only), part of the name should contain
For example, given an app ``common/models.py``::
+ from django.db import models
+
class Base(models.Model):
m2m = models.ManyToManyField(OtherModel, related_name="%(app_label)s_%(class)s_related")
@@ -949,6 +974,8 @@ relationship introduces links between the child model and each of its parents
(via an automatically-created :class:`~django.db.models.OneToOneField`).
For example::
+ from django.db import models
+
class Place(models.Model):
name = models.CharField(max_length=50)
address = models.CharField(max_length=80)
@@ -998,7 +1025,7 @@ If the parent has an ordering and you don't want the child to have any natural
ordering, you can explicitly disable it::
class ChildModel(ParentModel):
- ...
+ # ...
class Meta:
# Remove parent's ordering effect
ordering = []
@@ -1061,15 +1088,21 @@ Proxy models are declared like normal models. You tell Django that it's a
proxy model by setting the :attr:`~django.db.models.Options.proxy` attribute of
the ``Meta`` class to ``True``.
-For example, suppose you want to add a method to the ``Person`` model described
-above. You can do it like this::
+For example, suppose you want to add a method to the ``Person`` model. You can do it like this::
+
+ from django.db import models
+
+ class Person(models.Model):
+ first_name = models.CharField(max_length=30)
+ last_name = models.CharField(max_length=30)
class MyPerson(Person):
class Meta:
proxy = True
def do_something(self):
- ...
+ # ...
+ pass
The ``MyPerson`` class operates on the same database table as its parent
``Person`` class. In particular, any new instances of ``Person`` will also be
@@ -1125,8 +1158,11 @@ classes will still be available.
Continuing our example from above, you could change the default manager used
when you query the ``Person`` model like this::
+ from django.db import models
+
class NewManager(models.Manager):
- ...
+ # ...
+ pass
class MyPerson(Person):
objects = NewManager()
View
2  docs/topics/db/queries.txt
@@ -17,6 +17,8 @@ models, which comprise a Weblog application:
.. code-block:: python
+ from django.db import models
+
class Blog(models.Model):
name = models.CharField(max_length=100)
tagline = models.TextField()

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