1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
"""
Giving models custom methods
Any method you add to a model will be available to instances.
"""
import datetime
from django.db import models
from django.utils.encoding import python_2_unicode_compatible
@python_2_unicode_compatible
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.value_to_db_date(self.pub_date),
self.id])
return [self.__class__(*row) for row in cursor.fetchall()]
|
