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59 lines
1.8 KiB
59 lines
1.8 KiB
""" |
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3. Giving models custom methods |
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Any method you add to a model will be available to instances. |
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""" |
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from django.db import models |
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import datetime |
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class Article(models.Model): |
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headline = models.CharField(max_length=100) |
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pub_date = models.DateField() |
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def __unicode__(self): |
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return self.headline |
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def was_published_today(self): |
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return self.pub_date == datetime.date.today() |
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def articles_from_same_day_1(self): |
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return Article.objects.filter(pub_date=self.pub_date).exclude(id=self.id) |
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def articles_from_same_day_2(self): |
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""" |
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Verbose version of get_articles_from_same_day_1, which does a custom |
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database query for the sake of demonstration. |
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""" |
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from django.db import connection |
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cursor = connection.cursor() |
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cursor.execute(""" |
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SELECT id, headline, pub_date |
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FROM custom_methods_article |
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WHERE pub_date = %s |
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AND id != %s""", [connection.ops.value_to_db_date(self.pub_date), |
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self.id]) |
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# The asterisk in "(*row)" tells Python to expand the list into |
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# positional arguments to Article(). |
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return [self.__class__(*row) for row in cursor.fetchall()] |
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__test__ = {'API_TESTS':""" |
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# Create a couple of Articles. |
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>>> from datetime import date |
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>>> a = Article(id=None, headline='Area man programs in Python', pub_date=date(2005, 7, 27)) |
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>>> a.save() |
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>>> b = Article(id=None, headline='Beatles reunite', pub_date=date(2005, 7, 27)) |
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>>> b.save() |
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# Test the custom methods. |
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>>> a.was_published_today() |
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False |
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>>> a.articles_from_same_day_1() |
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[<Article: Beatles reunite>] |
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>>> a.articles_from_same_day_2() |
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[<Article: Beatles reunite>] |
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>>> b.articles_from_same_day_1() |
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[<Article: Area man programs in Python>] |
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>>> b.articles_from_same_day_2() |
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[<Article: Area man programs in Python>] |
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"""}
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