mirror of https://github.com/django/django.git
59 lines
1.7 KiB
Python
59 lines
1.7 KiB
Python
"""
|
|
3. Giving models custom methods
|
|
|
|
Any method you add to a model will be available to instances.
|
|
"""
|
|
|
|
from django.db import models
|
|
import datetime
|
|
|
|
class Article(models.Model):
|
|
headline = models.CharField(maxlength=100)
|
|
pub_date = models.DateField()
|
|
|
|
def __repr__(self):
|
|
return self.headline
|
|
|
|
def was_published_today(self):
|
|
return self.pub_date == datetime.date.today()
|
|
|
|
def get_articles_from_same_day_1(self):
|
|
return Article.objects.filter(pub_date=self.pub_date).exclude(id=self.id)
|
|
|
|
def get_articles_from_same_day_2(self):
|
|
"""
|
|
Verbose version of get_articles_from_same_day_1, which does a custom
|
|
database query for the sake of demonstration.
|
|
"""
|
|
from django.db import connection
|
|
cursor = connection.cursor()
|
|
cursor.execute("""
|
|
SELECT id, headline, pub_date
|
|
FROM custom_methods_article
|
|
WHERE pub_date = %s
|
|
AND id != %s""", [str(self.pub_date), self.id])
|
|
# The asterisk in "(*row)" tells Python to expand the list into
|
|
# positional arguments to Article().
|
|
return [self.__class__(*row) for row in cursor.fetchall()]
|
|
|
|
API_TESTS = """
|
|
# Create a couple of Articles.
|
|
>>> from datetime import date
|
|
>>> a = Article(id=None, headline='Area man programs in Python', pub_date=date(2005, 7, 27))
|
|
>>> a.save()
|
|
>>> b = Article(id=None, headline='Beatles reunite', pub_date=date(2005, 7, 27))
|
|
>>> b.save()
|
|
|
|
# Test the custom methods.
|
|
>>> a.was_published_today()
|
|
False
|
|
>>> a.get_articles_from_same_day_1()
|
|
[Beatles reunite]
|
|
>>> a.get_articles_from_same_day_2()
|
|
[Beatles reunite]
|
|
>>> b.get_articles_from_same_day_1()
|
|
[Area man programs in Python]
|
|
>>> b.get_articles_from_same_day_2()
|
|
[Area man programs in Python]
|
|
"""
|