"""

Giving models custom methods

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

"""

import datetime

from django.db import models

class Article(models.Model):

    headline = models.CharField(max_length=100)

    pub_date = models.DateField()

    def __str__(self):

        return self.headline

    def was_published_today(self):

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

    def articles_from_same_day_1(self):

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

    def 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

        with connection.cursor() as cursor:

            cursor.execute(

                """

                SELECT id, headline, pub_date

                FROM custom_methods_article

                WHERE pub_date = %s

                    AND id != %s""",

                [connection.ops.adapt_datefield_value(self.pub_date), self.id],

            )

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