mirror of
https://github.com/django/django.git
synced 2024-12-27 19:46:22 +00:00
25264c8604
git-svn-id: http://code.djangoproject.com/svn/django/trunk@549 bcc190cf-cafb-0310-a4f2-bffc1f526a37
88 lines
2.7 KiB
Python
88 lines
2.7 KiB
Python
"""
|
|
7. The lookup API
|
|
|
|
This demonstrates features of the database API.
|
|
"""
|
|
|
|
from django.core import meta
|
|
|
|
class Article(meta.Model):
|
|
headline = meta.CharField(maxlength=100)
|
|
pub_date = meta.DateTimeField()
|
|
class META:
|
|
ordering = ('-pub_date', 'headline')
|
|
|
|
def __repr__(self):
|
|
return self.headline
|
|
|
|
API_TESTS = """
|
|
# Create a couple of Articles.
|
|
>>> from datetime import datetime
|
|
>>> a1 = articles.Article(id=None, headline='Article 1', pub_date=datetime(2005, 7, 26))
|
|
>>> a1.save()
|
|
>>> a2 = articles.Article(id=None, headline='Article 2', pub_date=datetime(2005, 7, 27))
|
|
>>> a2.save()
|
|
>>> a3 = articles.Article(id=None, headline='Article 3', pub_date=datetime(2005, 7, 27))
|
|
>>> a3.save()
|
|
>>> a4 = articles.Article(id=None, headline='Article 4', pub_date=datetime(2005, 7, 28))
|
|
>>> a4.save()
|
|
|
|
# get_iterator() is just like get_list(), but it's a generator.
|
|
>>> for a in articles.get_iterator():
|
|
... print a.headline
|
|
Article 4
|
|
Article 2
|
|
Article 3
|
|
Article 1
|
|
|
|
# get_iterator() takes the same lookup arguments as get_list().
|
|
>>> for a in articles.get_iterator(headline__endswith='4'):
|
|
... print a.headline
|
|
Article 4
|
|
|
|
# get_count() returns the number of objects matching search criteria.
|
|
>>> articles.get_count()
|
|
4L
|
|
>>> articles.get_count(pub_date__exact=datetime(2005, 7, 27))
|
|
2L
|
|
>>> articles.get_count(headline__startswith='Blah blah')
|
|
0L
|
|
|
|
# get_in_bulk() takes a list of IDs and returns a dictionary mapping IDs
|
|
# to objects.
|
|
>>> articles.get_in_bulk([1, 2])
|
|
{1: Article 1, 2: Article 2}
|
|
>>> articles.get_in_bulk([3])
|
|
{3: Article 3}
|
|
>>> articles.get_in_bulk([1000])
|
|
{}
|
|
|
|
# get_values() is just like get_list(), except it returns a list of
|
|
# dictionaries instead of object instances -- and you can specify which fields
|
|
# you want to retrieve.
|
|
>>> articles.get_values(fields=['headline'])
|
|
[{'headline': 'Article 4'}, {'headline': 'Article 2'}, {'headline': 'Article 3'}, {'headline': 'Article 1'}]
|
|
>>> articles.get_values(pub_date__exact=datetime(2005, 7, 27), fields=['id'])
|
|
[{'id': 2}, {'id': 3}]
|
|
>>> articles.get_values(fields=['id', 'headline']) == [{'id': 4, 'headline': 'Article 4'}, {'id': 2, 'headline': 'Article 2'}, {'id': 3, 'headline': 'Article 3'}, {'id': 1, 'headline': 'Article 1'}]
|
|
True
|
|
|
|
# get_values_iterator() is just like get_values(), but it's a generator.
|
|
>>> for d in articles.get_values_iterator(fields=['id', 'headline']):
|
|
... i = d.items()
|
|
... i.sort()
|
|
... i
|
|
[('headline', 'Article 4'), ('id', 4)]
|
|
[('headline', 'Article 2'), ('id', 2)]
|
|
[('headline', 'Article 3'), ('id', 3)]
|
|
[('headline', 'Article 1'), ('id', 1)]
|
|
|
|
# Every DateField and DateTimeField creates get_next_by_FOO() and
|
|
# get_previous_by_FOO() methods.
|
|
>>> a3.get_next_by_pub_date()
|
|
Article 4
|
|
>>> a2.get_previous_by_pub_date()
|
|
Article 1
|
|
|
|
"""
|