queryset order_by method added, testcase, docs
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DOCS.rst
33
DOCS.rst
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@ -173,6 +173,19 @@ ManyToManyField, ForeignKey, OneToOneField
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<ModelB: id 2, field1 (CharField), field2 (CharField)>,
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<ModelC: id 3, field1 (CharField), field2 (CharField), field3 (CharField)> ]
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Non-Polymorphic Queries
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-----------------------
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>>> ModelA.base_objects.all()
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.
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[ <ModelA: id 1, field1 (CharField)>,
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<ModelA: id 2, field1 (CharField)>,
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<ModelA: id 3, field1 (CharField)> ]
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Each polymorphic model has 'base_objects' defined as a normal
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Django manager. Of course, arbitrary custom managers may be
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added to the models as well.
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More Queryset Methods
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---------------------
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@ -180,6 +193,9 @@ More Queryset Methods
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addition that the ``ModelX___field`` syntax can be used for the
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keyword arguments (but not for the non-keyword arguments).
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+ ``order_by()`` now similarly supports the ``ModelX___field`` syntax
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for specifying ordering through a field in a submodel.
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+ ``distinct()`` works as expected. It only regards the fields of
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the base class, but this should never make a difference.
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@ -201,19 +217,6 @@ More Queryset Methods
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+ ``defer()`` and ``only()`` are not yet supported (support will be added
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in the future).
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Non-Polymorphic Queries
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-----------------------
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>>> ModelA.base_objects.all()
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.
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[ <ModelA: id 1, field1 (CharField)>,
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<ModelA: id 2, field1 (CharField)>,
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<ModelA: id 3, field1 (CharField)> ]
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Each polymorphic model has 'base_objects' defined as a normal
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Django manager. Of course, arbitrary custom managers may be
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added to the models as well.
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manage.py dumpdata
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------------------
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@ -425,8 +428,8 @@ Restrictions & Caveats
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in PolymorphicModel, which causes some overhead. A minor patch to
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Django core would probably get rid of that.
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In General
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----------
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Project Status
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--------------
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It's important to consider that this code is very new and
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to some extent still experimental. Please see the docs for
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@ -105,6 +105,11 @@ class PolymorphicQuerySet(QuerySet):
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additional_args = _translate_polymorphic_filter_definitions_in_kwargs(self.model, kwargs) # filter_field='data'
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return super(PolymorphicQuerySet, self)._filter_or_exclude(negate, *(list(args) + additional_args), **kwargs)
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def order_by(self, *args, **kwargs):
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"""translate the field paths in the args, then call vanilla order_by."""
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new_args = [ _translate_polymorphic_field_path(self.model, a) for a in args ]
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return super(PolymorphicQuerySet, self).order_by(*new_args, **kwargs)
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def _process_aggregate_args(self, args, kwargs):
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"""for aggregate and annotate kwargs: allow ModelX___field syntax for kwargs, forbid it for args.
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Modifies kwargs if needed (these are Aggregate objects, we translate the lookup member variable)"""
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@ -345,12 +350,19 @@ def _translate_polymorphic_field_path(queryset_model, field_path):
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"""
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Translate a field path from a keyword argument, as used for
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PolymorphicQuerySet.filter()-like functions (and Q objects).
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Supports leading '-' (for order_by args).
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E.g.: ModelC___field3 is translated into modela__modelb__modelc__field3
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Returns: translated path
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Returns: translated path (unchanged, if no translation needed)
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"""
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classname, sep, pure_field_path = field_path.partition('___')
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if not sep: return field_path
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assert classname, 'PolymorphicModel: %s: bad field specification' % field_path
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negated = False
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if classname[0] == '-':
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negated = True
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classname = classname.lstrip('-')
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if '__' in classname:
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# the user has app label prepended to class name via __ => use Django's get_model function
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@ -398,7 +410,7 @@ def _translate_polymorphic_field_path(queryset_model, field_path):
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return ''
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basepath = _create_base_path(queryset_model, model)
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newpath = basepath + '__' if basepath else ''
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newpath = ('-' if negated else '') + basepath + ('__' if basepath else '')
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newpath += pure_field_path
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return newpath
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@ -92,7 +92,7 @@ class MgrInheritC(ShowFieldsAndTypes, MgrInheritB):
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class BlogBase(ShowFieldsAndTypes, PolymorphicModel):
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name = models.CharField(max_length=10)
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class BlogA(BlogBase):
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pass
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info = models.CharField(max_length=10)
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class BlogB(BlogBase):
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pass
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class BlogA_Entry(ShowFieldsAndTypes, PolymorphicModel):
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@ -119,25 +119,55 @@ class testclass(TestCase):
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print 'DiamondXY fields 2: field_b "%s", field_x "%s", field_y "%s"' % (o.field_b, o.field_x, o.field_y)
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if o.field_b != 'b': print '# Django model inheritance diamond problem detected'
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def test_annotate_aggregate(self):
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def test_annotate_aggregate_order(self):
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from django.db.models import Count
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BlogA.objects.all().delete()
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blog = BlogA.objects.create(name='B1')
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blog = BlogA.objects.create(name='B1', info='i1')
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entry1 = blog.bloga_entry_set.create(text='bla')
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entry2 = BlogA_Entry.objects.create(blog=blog, text='bla2')
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# create some BlogB to make the table more diverse
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o = BlogB.objects.create(name='Bb1')
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o = BlogB.objects.create(name='Bb2')
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o = BlogB.objects.create(name='Bb3')
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qs = BlogBase.objects.annotate(entrycount=Count('BlogA___bloga_entry'))
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assert qs[0].entrycount == 2
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x = BlogBase.objects.aggregate(entrycount=Count('BlogA___bloga_entry'))
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assert x['entrycount'] == 2
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def test_extra(self):
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Model2A.objects.create(field1='A1')
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Model2B.objects.create(field1='B1', field2='B2')
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Model2C.objects.create(field1='C1', field2='C2', field3='C3')
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# create some more blogs for next test
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b2 = BlogA.objects.create(name='B2', info='i2')
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b2 = BlogA.objects.create(name='B3', info='i3')
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b2 = BlogA.objects.create(name='B4', info='i4')
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b2 = BlogA.objects.create(name='B5', info='i5')
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# test ordering
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expected = '''
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[ <BlogB: id 4, name (CharField): "Bb3", >,
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<BlogB: id 3, name (CharField): "Bb2", >,
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<BlogB: id 2, name (CharField): "Bb1", >,
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<BlogA: id 8, name (CharField): "B5", info (CharField): "i5">,
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<BlogA: id 7, name (CharField): "B4", info (CharField): "i4">,
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<BlogA: id 6, name (CharField): "B3", info (CharField): "i3">,
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<BlogA: id 5, name (CharField): "B2", info (CharField): "i2">,
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<BlogA: id 1, name (CharField): "B1", info (CharField): "i1"> ]'''
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x = '\n' + repr(BlogBase.objects.order_by('-name'))
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assert x == expected
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expected='''
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[ <BlogA: id 8, name (CharField): "B5", info (CharField): "i5">,
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<BlogA: id 7, name (CharField): "B4", info (CharField): "i4">,
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<BlogA: id 6, name (CharField): "B3", info (CharField): "i3">,
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<BlogA: id 5, name (CharField): "B2", info (CharField): "i2">,
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<BlogA: id 1, name (CharField): "B1", info (CharField): "i1">,
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<BlogB: id 2, name (CharField): "Bb1", >,
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<BlogB: id 3, name (CharField): "Bb2", >,
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<BlogB: id 4, name (CharField): "Bb3", > ]'''
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x = '\n' + repr(BlogBase.objects.order_by('-BlogA___info'))
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assert x == expected
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__test__ = {"doctest": """
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#######################################################
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