Migrated select_related doctests. Thanks to Eric Florenzano.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@13828 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Russell Keith-Magee
parent
2055fdbe97
commit
4f48f25b29
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@ -56,134 +56,4 @@ class Species(models.Model):
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name = models.CharField(max_length=50)
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genus = models.ForeignKey(Genus)
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def __unicode__(self):
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return self.name
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def create_tree(stringtree):
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"""Helper to create a complete tree"""
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names = stringtree.split()
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models = [Domain, Kingdom, Phylum, Klass, Order, Family, Genus, Species]
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assert len(names) == len(models), (names, models)
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parent = None
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for name, model in zip(names, models):
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try:
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obj = model.objects.get(name=name)
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except model.DoesNotExist:
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obj = model(name=name)
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if parent:
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setattr(obj, parent.__class__.__name__.lower(), parent)
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obj.save()
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parent = obj
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__test__ = {'API_TESTS':"""
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# Set up.
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# The test runner sets settings.DEBUG to False, but we want to gather queries
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# so we'll set it to True here and reset it at the end of the test suite.
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>>> from django.conf import settings
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>>> settings.DEBUG = True
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>>> create_tree("Eukaryota Animalia Anthropoda Insecta Diptera Drosophilidae Drosophila melanogaster")
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>>> create_tree("Eukaryota Animalia Chordata Mammalia Primates Hominidae Homo sapiens")
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>>> create_tree("Eukaryota Plantae Magnoliophyta Magnoliopsida Fabales Fabaceae Pisum sativum")
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>>> create_tree("Eukaryota Fungi Basidiomycota Homobasidiomycatae Agaricales Amanitacae Amanita muscaria")
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>>> from django import db
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# Normally, accessing FKs doesn't fill in related objects:
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>>> db.reset_queries()
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>>> fly = Species.objects.get(name="melanogaster")
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>>> fly.genus.family.order.klass.phylum.kingdom.domain
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<Domain: Eukaryota>
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>>> len(db.connection.queries)
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8
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# However, a select_related() call will fill in those related objects without any extra queries:
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>>> db.reset_queries()
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>>> person = Species.objects.select_related(depth=10).get(name="sapiens")
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>>> person.genus.family.order.klass.phylum.kingdom.domain
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<Domain: Eukaryota>
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>>> len(db.connection.queries)
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1
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# select_related() also of course applies to entire lists, not just items.
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# Without select_related()
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>>> db.reset_queries()
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>>> world = Species.objects.all()
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>>> [o.genus.family for o in world]
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[<Family: Drosophilidae>, <Family: Hominidae>, <Family: Fabaceae>, <Family: Amanitacae>]
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>>> len(db.connection.queries)
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9
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# With select_related():
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>>> db.reset_queries()
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>>> world = Species.objects.all().select_related()
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>>> [o.genus.family for o in world]
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[<Family: Drosophilidae>, <Family: Hominidae>, <Family: Fabaceae>, <Family: Amanitacae>]
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>>> len(db.connection.queries)
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1
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# The "depth" argument to select_related() will stop the descent at a particular level:
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>>> db.reset_queries()
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>>> pea = Species.objects.select_related(depth=1).get(name="sativum")
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>>> pea.genus.family.order.klass.phylum.kingdom.domain
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<Domain: Eukaryota>
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# Notice: one fewer queries than above because of depth=1
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>>> len(db.connection.queries)
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7
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>>> db.reset_queries()
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>>> pea = Species.objects.select_related(depth=5).get(name="sativum")
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>>> pea.genus.family.order.klass.phylum.kingdom.domain
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<Domain: Eukaryota>
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>>> len(db.connection.queries)
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3
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>>> db.reset_queries()
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>>> world = Species.objects.all().select_related(depth=2)
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>>> [o.genus.family.order for o in world]
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[<Order: Diptera>, <Order: Primates>, <Order: Fabales>, <Order: Agaricales>]
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>>> len(db.connection.queries)
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5
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>>> s = Species.objects.all().select_related(depth=1).extra(select={'a': 'select_related_species.id + 10'})[0]
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>>> s.id + 10 == s.a
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True
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# The optional fields passed to select_related() control which related models
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# we pull in. This allows for smaller queries and can act as an alternative
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# (or, in addition to) the depth parameter.
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# In the next two cases, we explicitly say to select the 'genus' and
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# 'genus.family' models, leading to the same number of queries as before.
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>>> db.reset_queries()
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>>> world = Species.objects.select_related('genus__family')
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>>> [o.genus.family for o in world]
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[<Family: Drosophilidae>, <Family: Hominidae>, <Family: Fabaceae>, <Family: Amanitacae>]
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>>> len(db.connection.queries)
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1
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>>> db.reset_queries()
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>>> world = Species.objects.filter(genus__name='Amanita').select_related('genus__family')
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>>> [o.genus.family.order for o in world]
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[<Order: Agaricales>]
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>>> len(db.connection.queries)
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2
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>>> db.reset_queries()
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>>> Species.objects.all().select_related('genus__family__order').order_by('id')[0:1].get().genus.family.order.name
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u'Diptera'
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>>> len(db.connection.queries)
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1
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# Specifying both "depth" and fields is an error.
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>>> Species.objects.select_related('genus__family__order', depth=4)
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Traceback (most recent call last):
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...
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TypeError: Cannot pass both "depth" and fields to select_related()
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# Reset DEBUG to where we found it.
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>>> settings.DEBUG = False
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"""}
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return self.name
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@ -0,0 +1,166 @@
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from django.test import TestCase
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from django.conf import settings
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from django import db
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from models import Domain, Kingdom, Phylum, Klass, Order, Family, Genus, Species
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class SelectRelatedTests(TestCase):
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def create_tree(self, stringtree):
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"""
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Helper to create a complete tree.
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"""
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names = stringtree.split()
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models = [Domain, Kingdom, Phylum, Klass, Order, Family, Genus, Species]
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assert len(names) == len(models), (names, models)
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parent = None
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for name, model in zip(names, models):
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try:
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obj = model.objects.get(name=name)
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except model.DoesNotExist:
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obj = model(name=name)
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if parent:
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setattr(obj, parent.__class__.__name__.lower(), parent)
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obj.save()
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parent = obj
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def create_base_data(self):
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self.create_tree("Eukaryota Animalia Anthropoda Insecta Diptera Drosophilidae Drosophila melanogaster")
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self.create_tree("Eukaryota Animalia Chordata Mammalia Primates Hominidae Homo sapiens")
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self.create_tree("Eukaryota Plantae Magnoliophyta Magnoliopsida Fabales Fabaceae Pisum sativum")
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self.create_tree("Eukaryota Fungi Basidiomycota Homobasidiomycatae Agaricales Amanitacae Amanita muscaria")
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def setUp(self):
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# The test runner sets settings.DEBUG to False, but we want to gather
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# queries so we'll set it to True here and reset it at the end of the
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# test case.
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self.create_base_data()
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settings.DEBUG = True
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db.reset_queries()
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def tearDown(self):
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settings.DEBUG = False
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def test_access_fks_without_select_related(self):
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"""
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Normally, accessing FKs doesn't fill in related objects
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"""
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fly = Species.objects.get(name="melanogaster")
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domain = fly.genus.family.order.klass.phylum.kingdom.domain
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self.assertEqual(domain.name, 'Eukaryota')
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self.assertEqual(len(db.connection.queries), 8)
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def test_access_fks_with_select_related(self):
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"""
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A select_related() call will fill in those related objects without any
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extra queries
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"""
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person = Species.objects.select_related(depth=10).get(name="sapiens")
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domain = person.genus.family.order.klass.phylum.kingdom.domain
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self.assertEqual(domain.name, 'Eukaryota')
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self.assertEqual(len(db.connection.queries), 1)
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def test_list_without_select_related(self):
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"""
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select_related() also of course applies to entire lists, not just
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items. This test verifies the expected behavior without select_related.
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"""
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world = Species.objects.all()
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families = [o.genus.family.name for o in world]
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self.assertEqual(families, [
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'Drosophilidae',
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'Hominidae',
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'Fabaceae',
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'Amanitacae',
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])
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self.assertEqual(len(db.connection.queries), 9)
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def test_list_with_select_related(self):
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"""
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select_related() also of course applies to entire lists, not just
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items. This test verifies the expected behavior with select_related.
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"""
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world = Species.objects.all().select_related()
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families = [o.genus.family.name for o in world]
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self.assertEqual(families, [
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'Drosophilidae',
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'Hominidae',
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'Fabaceae',
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'Amanitacae',
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])
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self.assertEqual(len(db.connection.queries), 1)
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def test_depth(self, depth=1, expected=7):
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"""
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The "depth" argument to select_related() will stop the descent at a
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particular level.
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"""
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pea = Species.objects.select_related(depth=depth).get(name="sativum")
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self.assertEqual(
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pea.genus.family.order.klass.phylum.kingdom.domain.name,
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'Eukaryota'
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)
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# Notice: one fewer queries than above because of depth=1
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self.assertEqual(len(db.connection.queries), expected)
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def test_larger_depth(self):
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"""
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The "depth" argument to select_related() will stop the descent at a
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particular level. This tests a larger depth value.
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"""
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self.test_depth(depth=5, expected=3)
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def test_list_with_depth(self):
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"""
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The "depth" argument to select_related() will stop the descent at a
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particular level. This can be used on lists as well.
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"""
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world = Species.objects.all().select_related(depth=2)
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orders = [o.genus.family.order.name for o in world]
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self.assertEqual(orders,
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['Diptera', 'Primates', 'Fabales', 'Agaricales'])
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self.assertEqual(len(db.connection.queries), 5)
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def test_select_related_with_extra(self):
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s = Species.objects.all().select_related(depth=1)\
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.extra(select={'a': 'select_related_species.id + 10'})[0]
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self.assertEqual(s.id + 10, s.a)
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def test_certain_fields(self):
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"""
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The optional fields passed to select_related() control which related
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models we pull in. This allows for smaller queries and can act as an
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alternative (or, in addition to) the depth parameter.
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In this case, we explicitly say to select the 'genus' and
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'genus.family' models, leading to the same number of queries as before.
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"""
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world = Species.objects.select_related('genus__family')
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families = [o.genus.family.name for o in world]
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self.assertEqual(families,
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['Drosophilidae', 'Hominidae', 'Fabaceae', 'Amanitacae'])
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self.assertEqual(len(db.connection.queries), 1)
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def test_more_certain_fields(self):
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"""
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In this case, we explicitly say to select the 'genus' and
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'genus.family' models, leading to the same number of queries as before.
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"""
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world = Species.objects.filter(genus__name='Amanita')\
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.select_related('genus__family')
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orders = [o.genus.family.order.name for o in world]
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self.assertEqual(orders, [u'Agaricales'])
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self.assertEqual(len(db.connection.queries), 2)
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def test_field_traversal(self):
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s = Species.objects.all().select_related('genus__family__order'
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).order_by('id')[0:1].get().genus.family.order.name
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self.assertEqual(s, u'Diptera')
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self.assertEqual(len(db.connection.queries), 1)
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def test_depth_fields_fails(self):
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self.assertRaises(TypeError,
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Species.objects.select_related,
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'genus__family__order', depth=4
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)
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