[1.2.X] Migrated defer doctests. Thanks to Alex Gaynor.
Backport of r13777 from trunk. git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13794 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Russell Keith-Magee
parent
592288fb95
commit
7fbdeb49f9
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@ -3,7 +3,7 @@ Tests for defer() and only().
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"""
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from django.db import models
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from django.db.models.query_utils import DeferredAttribute
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class Secondary(models.Model):
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first = models.CharField(max_length=50)
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@ -22,165 +22,3 @@ class Child(Primary):
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class BigChild(Primary):
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other = models.CharField(max_length=50)
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def count_delayed_fields(obj, debug=False):
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"""
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Returns the number of delayed attributes on the given model instance.
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"""
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count = 0
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for field in obj._meta.fields:
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if isinstance(obj.__class__.__dict__.get(field.attname),
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DeferredAttribute):
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if debug:
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print field.name, field.attname
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count += 1
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return count
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__test__ = {"API_TEST": """
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To all outward appearances, instances with deferred fields look the same as
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normal instances when we examine attribute values. Therefore we test for the
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number of deferred fields on returned instances (by poking at the internals),
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as a way to observe what is going on.
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>>> s1 = Secondary.objects.create(first="x1", second="y1")
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>>> p1 = Primary.objects.create(name="p1", value="xx", related=s1)
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>>> qs = Primary.objects.all()
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>>> count_delayed_fields(qs.defer('name')[0])
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1
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>>> count_delayed_fields(qs.only('name')[0])
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2
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>>> count_delayed_fields(qs.defer('related__first')[0])
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0
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>>> obj = qs.select_related().only('related__first')[0]
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>>> count_delayed_fields(obj)
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2
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>>> obj.related_id == s1.pk
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True
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>>> count_delayed_fields(qs.defer('name').extra(select={'a': 1})[0])
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1
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>>> count_delayed_fields(qs.extra(select={'a': 1}).defer('name')[0])
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1
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>>> count_delayed_fields(qs.defer('name').defer('value')[0])
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2
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>>> count_delayed_fields(qs.only('name').only('value')[0])
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2
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>>> count_delayed_fields(qs.only('name').defer('value')[0])
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2
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>>> count_delayed_fields(qs.only('name', 'value').defer('value')[0])
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2
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>>> count_delayed_fields(qs.defer('name').only('value')[0])
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2
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>>> obj = qs.only()[0]
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>>> count_delayed_fields(qs.defer(None)[0])
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0
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>>> count_delayed_fields(qs.only('name').defer(None)[0])
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0
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User values() won't defer anything (you get the full list of dictionaries
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back), but it still works.
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>>> qs.defer('name').values()[0] == {'id': p1.id, 'name': u'p1', 'value': 'xx', 'related_id': s1.id}
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True
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>>> qs.only('name').values()[0] == {'id': p1.id, 'name': u'p1', 'value': 'xx', 'related_id': s1.id}
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True
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Using defer() and only() with get() is also valid.
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>>> count_delayed_fields(qs.defer('name').get(pk=p1.pk))
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1
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>>> count_delayed_fields(qs.only('name').get(pk=p1.pk))
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2
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# KNOWN NOT TO WORK: >>> count_delayed_fields(qs.only('name').select_related('related')[0])
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# KNOWN NOT TO WORK >>> count_delayed_fields(qs.defer('related').select_related('related')[0])
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# Saving models with deferred fields is possible (but inefficient, since every
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# field has to be retrieved first).
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>>> obj = Primary.objects.defer("value").get(name="p1")
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>>> obj.name = "a new name"
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>>> obj.save()
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>>> Primary.objects.all()
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[<Primary: a new name>]
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# Regression for #10572 - A subclass with no extra fields can defer fields from the base class
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>>> _ = Child.objects.create(name="c1", value="foo", related=s1)
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# You can defer a field on a baseclass when the subclass has no fields
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>>> obj = Child.objects.defer("value").get(name="c1")
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>>> count_delayed_fields(obj)
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1
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>>> obj.name
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u"c1"
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>>> obj.value
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u"foo"
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>>> obj.name = "c2"
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>>> obj.save()
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# You can retrive a single column on a base class with no fields
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>>> obj = Child.objects.only("name").get(name="c2")
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>>> count_delayed_fields(obj)
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3
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>>> obj.name
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u"c2"
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>>> obj.value
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u"foo"
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>>> obj.name = "cc"
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>>> obj.save()
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>>> _ = BigChild.objects.create(name="b1", value="foo", related=s1, other="bar")
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# You can defer a field on a baseclass
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>>> obj = BigChild.objects.defer("value").get(name="b1")
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>>> count_delayed_fields(obj)
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1
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>>> obj.name
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u"b1"
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>>> obj.value
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u"foo"
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>>> obj.other
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u"bar"
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>>> obj.name = "b2"
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>>> obj.save()
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# You can defer a field on a subclass
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>>> obj = BigChild.objects.defer("other").get(name="b2")
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>>> count_delayed_fields(obj)
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1
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>>> obj.name
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u"b2"
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>>> obj.value
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u"foo"
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>>> obj.other
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u"bar"
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>>> obj.name = "b3"
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>>> obj.save()
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# You can retrieve a single field on a baseclass
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>>> obj = BigChild.objects.only("name").get(name="b3")
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>>> count_delayed_fields(obj)
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4
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>>> obj.name
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u"b3"
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>>> obj.value
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u"foo"
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>>> obj.other
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u"bar"
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>>> obj.name = "b4"
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>>> obj.save()
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# You can retrieve a single field on a baseclass
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>>> obj = BigChild.objects.only("other").get(name="b4")
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>>> count_delayed_fields(obj)
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4
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>>> obj.name
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u"b4"
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>>> obj.value
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u"foo"
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>>> obj.other
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u"bar"
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>>> obj.name = "bb"
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>>> obj.save()
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"""}
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@ -0,0 +1,137 @@
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from django.db.models.query_utils import DeferredAttribute
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from django.test import TestCase
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from models import Secondary, Primary, Child, BigChild
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class DeferTests(TestCase):
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def assert_delayed(self, obj, num):
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count = 0
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for field in obj._meta.fields:
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if isinstance(obj.__class__.__dict__.get(field.attname),
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DeferredAttribute):
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count += 1
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self.assertEqual(count, num)
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def test_defer(self):
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# To all outward appearances, instances with deferred fields look the
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# same as normal instances when we examine attribute values. Therefore
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# we test for the number of deferred fields on returned instances (by
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# poking at the internals), as a way to observe what is going on.
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s1 = Secondary.objects.create(first="x1", second="y1")
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p1 = Primary.objects.create(name="p1", value="xx", related=s1)
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qs = Primary.objects.all()
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self.assert_delayed(qs.defer("name")[0], 1)
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self.assert_delayed(qs.only("name")[0], 2)
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self.assert_delayed(qs.defer("related__first")[0], 0)
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obj = qs.select_related().only("related__first")[0]
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self.assert_delayed(obj, 2)
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self.assertEqual(obj.related_id, s1.pk)
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self.assert_delayed(qs.defer("name").extra(select={"a": 1})[0], 1)
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self.assert_delayed(qs.extra(select={"a": 1}).defer("name")[0], 1)
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self.assert_delayed(qs.defer("name").defer("value")[0], 2)
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self.assert_delayed(qs.only("name").only("value")[0], 2)
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self.assert_delayed(qs.only("name").defer("value")[0], 2)
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self.assert_delayed(qs.only("name", "value").defer("value")[0], 2)
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self.assert_delayed(qs.defer("name").only("value")[0], 2)
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obj = qs.only()[0]
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self.assert_delayed(qs.defer(None)[0], 0)
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self.assert_delayed(qs.only("name").defer(None)[0], 0)
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# User values() won't defer anything (you get the full list of
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# dictionaries back), but it still works.
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self.assertEqual(qs.defer("name").values()[0], {
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"id": p1.id,
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"name": "p1",
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"value": "xx",
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"related_id": s1.id,
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})
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self.assertEqual(qs.only("name").values()[0], {
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"id": p1.id,
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"name": "p1",
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"value": "xx",
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"related_id": s1.id,
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})
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# Using defer() and only() with get() is also valid.
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self.assert_delayed(qs.defer("name").get(pk=p1.pk), 1)
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self.assert_delayed(qs.only("name").get(pk=p1.pk), 2)
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# DOES THIS WORK?
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self.assert_delayed(qs.only("name").select_related("related")[0], 1)
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self.assert_delayed(qs.defer("related").select_related("related")[0], 0)
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# Saving models with deferred fields is possible (but inefficient,
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# since every field has to be retrieved first).
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obj = Primary.objects.defer("value").get(name="p1")
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obj.name = "a new name"
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obj.save()
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self.assertQuerysetEqual(
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Primary.objects.all(), [
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"a new name",
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],
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lambda p: p.name
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)
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# Regression for #10572 - A subclass with no extra fields can defer
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# fields from the base class
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Child.objects.create(name="c1", value="foo", related=s1)
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# You can defer a field on a baseclass when the subclass has no fields
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obj = Child.objects.defer("value").get(name="c1")
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self.assert_delayed(obj, 1)
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self.assertEqual(obj.name, "c1")
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self.assertEqual(obj.value, "foo")
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obj.name = "c2"
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obj.save()
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# You can retrive a single column on a base class with no fields
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obj = Child.objects.only("name").get(name="c2")
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self.assert_delayed(obj, 3)
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self.assertEqual(obj.name, "c2")
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self.assertEqual(obj.value, "foo")
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obj.name = "cc"
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obj.save()
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BigChild.objects.create(name="b1", value="foo", related=s1, other="bar")
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# You can defer a field on a baseclass
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obj = BigChild.objects.defer("value").get(name="b1")
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self.assert_delayed(obj, 1)
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self.assertEqual(obj.name, "b1")
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self.assertEqual(obj.value, "foo")
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self.assertEqual(obj.other, "bar")
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obj.name = "b2"
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obj.save()
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# You can defer a field on a subclass
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obj = BigChild.objects.defer("other").get(name="b2")
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self.assert_delayed(obj, 1)
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self.assertEqual(obj.name, "b2")
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self.assertEqual(obj.value, "foo")
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self.assertEqual(obj.other, "bar")
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obj.name = "b3"
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obj.save()
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# You can retrieve a single field on a baseclass
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obj = BigChild.objects.only("name").get(name="b3")
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self.assert_delayed(obj, 4)
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self.assertEqual(obj.name, "b3")
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self.assertEqual(obj.value, "foo")
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self.assertEqual(obj.other, "bar")
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obj.name = "b4"
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obj.save()
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# You can retrieve a single field on a baseclass
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obj = BigChild.objects.only("other").get(name="b4")
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self.assert_delayed(obj, 4)
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self.assertEqual(obj.name, "b4")
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self.assertEqual(obj.value, "foo")
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self.assertEqual(obj.other, "bar")
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obj.name = "bb"
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obj.save()
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