""" 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()]