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3deff41a32
and models that have multiple paths to them from other models. git-svn-id: http://code.djangoproject.com/svn/django/trunk@8559 bcc190cf-cafb-0310-a4f2-bffc1f526a37
104 lines
3.8 KiB
Python
104 lines
3.8 KiB
Python
from django.db import models
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class Building(models.Model):
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name = models.CharField(max_length=10)
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def __unicode__(self):
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return u"Building: %s" % self.name
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class Device(models.Model):
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building = models.ForeignKey('Building')
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name = models.CharField(max_length=10)
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def __unicode__(self):
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return u"device '%s' in building %s" % (self.name, self.building)
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class Port(models.Model):
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device = models.ForeignKey('Device')
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port_number = models.CharField(max_length=10)
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def __unicode__(self):
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return u"%s/%s" % (self.device.name, self.port_number)
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class Connection(models.Model):
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start = models.ForeignKey(Port, related_name='connection_start',
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unique=True)
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end = models.ForeignKey(Port, related_name='connection_end', unique=True)
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def __unicode__(self):
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return u"%s to %s" % (self.start, self.end)
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# Another non-tree hierarchy that exercises code paths similar to the above
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# example, but in a slightly different configuration.
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class TUser(models.Model):
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name = models.CharField(max_length=200)
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class Person(models.Model):
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user = models.ForeignKey(TUser, unique=True)
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class Organizer(models.Model):
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person = models.ForeignKey(Person)
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class Student(models.Model):
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person = models.ForeignKey(Person)
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class Class(models.Model):
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org = models.ForeignKey(Organizer)
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class Enrollment(models.Model):
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std = models.ForeignKey(Student)
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cls = models.ForeignKey(Class)
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__test__ = {'API_TESTS': """
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Regression test for bug #7110. When using select_related(), we must query the
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Device and Building tables using two different aliases (each) in order to
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differentiate the start and end Connection fields. The net result is that both
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the "connections = ..." queries here should give the same results without
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pulling in more than the absolute minimum number of tables (history has
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shown that it's easy to make a mistake in the implementation and include some
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unnecessary bonus joins).
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>>> b=Building.objects.create(name='101')
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>>> dev1=Device.objects.create(name="router", building=b)
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>>> dev2=Device.objects.create(name="switch", building=b)
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>>> dev3=Device.objects.create(name="server", building=b)
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>>> port1=Port.objects.create(port_number='4',device=dev1)
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>>> port2=Port.objects.create(port_number='7',device=dev2)
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>>> port3=Port.objects.create(port_number='1',device=dev3)
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>>> c1=Connection.objects.create(start=port1, end=port2)
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>>> c2=Connection.objects.create(start=port2, end=port3)
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>>> connections=Connection.objects.filter(start__device__building=b, end__device__building=b).order_by('id')
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>>> [(c.id, unicode(c.start), unicode(c.end)) for c in connections]
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[(1, u'router/4', u'switch/7'), (2, u'switch/7', u'server/1')]
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>>> connections=Connection.objects.filter(start__device__building=b, end__device__building=b).select_related().order_by('id')
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>>> [(c.id, unicode(c.start), unicode(c.end)) for c in connections]
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[(1, u'router/4', u'switch/7'), (2, u'switch/7', u'server/1')]
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# This final query should only join seven tables (port, device and building
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# twice each, plus connection once).
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>>> connections.query.count_active_tables()
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7
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Regression test for bug #8106. Same sort of problem as the previous test, but
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this time there are more extra tables to pull in as part of the
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select_related() and some of them could potentially clash (so need to be kept
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separate).
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>>> us = TUser.objects.create(name="std")
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>>> usp = Person.objects.create(user=us)
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>>> uo = TUser.objects.create(name="org")
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>>> uop = Person.objects.create(user=uo)
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>>> s = Student.objects.create(person = usp)
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>>> o = Organizer.objects.create(person = uop)
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>>> c = Class.objects.create(org=o)
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>>> e = Enrollment.objects.create(std=s, cls=c)
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>>> e_related = Enrollment.objects.all().select_related()[0]
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>>> e_related.std.person.user.name
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u"std"
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>>> e_related.cls.org.person.user.name
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u"org"
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"""}
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