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Malcolm Tredinnick 61cc4a1eee Fixed #8819 -- Don't include two copies of extra-select columns in the query.
This was triggered by r8794, but was, in fact, fairly fragile before then. The
current fix is the correct way we should be doing this.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8898 bcc190cf-cafb-0310-a4f2-bffc1f526a37
2008-09-03 03:48:25 +00:00

111 lines
4.0 KiB
Python

import copy
from django.contrib.auth.models import User
from django.db import models
from django.db.models.query import Q
from django.utils.datastructures import SortedDict
class RevisionableModel(models.Model):
base = models.ForeignKey('self', null=True)
title = models.CharField(blank=True, max_length=255)
def __unicode__(self):
return u"%s (%s, %s)" % (self.title, self.id, self.base.id)
def save(self, force_insert=False, force_update=False):
super(RevisionableModel, self).save(force_insert, force_update)
if not self.base:
self.base = self
super(RevisionableModel, self).save()
def new_revision(self):
new_revision = copy.copy(self)
new_revision.pk = None
return new_revision
class Order(models.Model):
created_by = models.ForeignKey(User)
text = models.TextField()
__test__ = {"API_TESTS": """
# Regression tests for #7314 and #7372
>>> rm = RevisionableModel.objects.create(title='First Revision')
>>> rm.pk, rm.base.pk
(1, 1)
>>> rm2 = rm.new_revision()
>>> rm2.title = "Second Revision"
>>> rm2.save()
>>> print u"%s of %s" % (rm2.title, rm2.base.title)
Second Revision of First Revision
>>> rm2.pk, rm2.base.pk
(2, 1)
Queryset to match most recent revision:
>>> qs = RevisionableModel.objects.extra(where=["%(table)s.id IN (SELECT MAX(rev.id) FROM %(table)s rev GROUP BY rev.base_id)" % {'table': RevisionableModel._meta.db_table,}],)
>>> qs
[<RevisionableModel: Second Revision (2, 1)>]
Queryset to search for string in title:
>>> qs2 = RevisionableModel.objects.filter(title__contains="Revision")
>>> qs2
[<RevisionableModel: First Revision (1, 1)>, <RevisionableModel: Second Revision (2, 1)>]
Following queryset should return the most recent revision:
>>> qs & qs2
[<RevisionableModel: Second Revision (2, 1)>]
>>> u = User.objects.create_user(username="fred", password="secret", email="fred@example.com")
# General regression tests: extra select parameters should stay tied to their
# corresponding select portions. Applies when portions are updated or otherwise
# moved around.
>>> qs = User.objects.extra(select=SortedDict((("alpha", "%s"), ("beta", "2"), ("gamma", "%s"))), select_params=(1, 3))
>>> qs = qs.extra(select={"beta": 4})
>>> qs = qs.extra(select={"alpha": "%s"}, select_params=[5])
>>> result = {'alpha': 5, 'beta': 4, 'gamma': 3}
>>> list(qs.filter(id=u.id).values('alpha', 'beta', 'gamma')) == [result]
True
# Regression test for #7957: Combining extra() calls should leave the
# corresponding parameters associated with the right extra() bit. I.e. internal
# dictionary must remain sorted.
>>> User.objects.extra(select={"alpha": "%s"}, select_params=(1,)).extra(select={"beta": "%s"}, select_params=(2,))[0].alpha
1
>>> User.objects.extra(select={"beta": "%s"}, select_params=(1,)).extra(select={"alpha": "%s"}, select_params=(2,))[0].alpha
2
# Regression test for #7961: When not using a portion of an extra(...) in a
# query, remove any corresponding parameters from the query as well.
>>> list(User.objects.extra(select={"alpha": "%s"}, select_params=(-6,)).filter(id=u.id).values_list('id', flat=True)) == [u.id]
True
# Regression test for #8063: limiting a query shouldn't discard any extra()
# bits.
>>> qs = User.objects.all().extra(where=['id=%s'], params=[u.id])
>>> qs
[<User: fred>]
>>> qs[:1]
[<User: fred>]
# Regression test for #8039: Ordering sometimes removed relevant tables from
# extra(). This test is the critical case: ordering uses a table, but then
# removes the reference because of an optimisation. The table should still be
# present because of the extra() call.
>>> Order.objects.extra(where=["username=%s"], params=["fred"], tables=["auth_user"]).order_by('created_by')
[]
# Regression test for #8819: Fields in the extra(select=...) list should be
# available to extra(order_by=...).
>>> User.objects.extra(select={'extra_field': 1}).distinct()
[<User: fred>]
>>> User.objects.extra(select={'extra_field': 1}, order_by=['extra_field'])
[<User: fred>]
>>> User.objects.extra(select={'extra_field': 1}, order_by=['extra_field']).distinct()
[<User: fred>]
"""}