1 """

     2 3. Giving models custom methods

     3 

     4 Any method you add to a model will be available to instances.

     5 """

     6 

     7 from django.db import models

     8 import datetime

     9 

    10 class Article(models.Model):

    11     headline = models.CharField(max_length=100)

    12     pub_date = models.DateField()

    13 

    14     def __unicode__(self):

    15         return self.headline

    16 

    17     def was_published_today(self):

    18         return self.pub_date == datetime.date.today()

    19 

    20     def articles_from_same_day_1(self):

    21         return Article.objects.filter(pub_date=self.pub_date).exclude(id=self.id)

    22 

    23     def articles_from_same_day_2(self):

    24         """

    25         Verbose version of get_articles_from_same_day_1, which does a custom

    26         database query for the sake of demonstration.

    27         """

    28         from django.db import connection

    29         cursor = connection.cursor()

    30         cursor.execute("""

    31             SELECT id, headline, pub_date

    32             FROM custom_methods_article

    33             WHERE pub_date = %s

    34                 AND id != %s""", [connection.ops.value_to_db_date(self.pub_date),

    35                                   self.id])

    36         return [self.__class__(*row) for row in cursor.fetchall()]