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Diffstat (limited to 'tests/modeltests/m2m_through/models.py')
| -rw-r--r-- | tests/modeltests/m2m_through/models.py | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/tests/modeltests/m2m_through/models.py b/tests/modeltests/m2m_through/models.py new file mode 100644 index 0000000000..fa9fa714a5 --- /dev/null +++ b/tests/modeltests/m2m_through/models.py @@ -0,0 +1,337 @@ +from django.db import models +from datetime import datetime + +# M2M described on one of the models +class Person(models.Model): + name = models.CharField(max_length=128) + + class Meta: + ordering = ('name',) + + def __unicode__(self): + return self.name + +class Group(models.Model): + name = models.CharField(max_length=128) + members = models.ManyToManyField(Person, through='Membership') + custom_members = models.ManyToManyField(Person, through='CustomMembership', related_name="custom") + nodefaultsnonulls = models.ManyToManyField(Person, through='TestNoDefaultsOrNulls', related_name="testnodefaultsnonulls") + + class Meta: + ordering = ('name',) + + def __unicode__(self): + return self.name + +class Membership(models.Model): + person = models.ForeignKey(Person) + group = models.ForeignKey(Group) + date_joined = models.DateTimeField(default=datetime.now) + invite_reason = models.CharField(max_length=64, null=True) + + class Meta: + ordering = ('date_joined', 'invite_reason', 'group') + + def __unicode__(self): + return "%s is a member of %s" % (self.person.name, self.group.name) + +class CustomMembership(models.Model): + person = models.ForeignKey(Person, db_column="custom_person_column", related_name="custom_person_related_name") + group = models.ForeignKey(Group) + weird_fk = models.ForeignKey(Membership, null=True) + date_joined = models.DateTimeField(default=datetime.now) + + def __unicode__(self): + return "%s is a member of %s" % (self.person.name, self.group.name) + + class Meta: + db_table = "test_table" + +class TestNoDefaultsOrNulls(models.Model): + person = models.ForeignKey(Person) + group = models.ForeignKey(Group) + nodefaultnonull = models.CharField(max_length=5) + +class PersonSelfRefM2M(models.Model): + name = models.CharField(max_length=5) + friends = models.ManyToManyField('self', through="Friendship", symmetrical=False) + + def __unicode__(self): + return self.name + +class Friendship(models.Model): + first = models.ForeignKey(PersonSelfRefM2M, related_name="rel_from_set") + second = models.ForeignKey(PersonSelfRefM2M, related_name="rel_to_set") + date_friended = models.DateTimeField() + +__test__ = {'API_TESTS':""" +>>> from datetime import datetime + +### Creation and Saving Tests ### + +>>> bob = Person.objects.create(name='Bob') +>>> jim = Person.objects.create(name='Jim') +>>> jane = Person.objects.create(name='Jane') +>>> rock = Group.objects.create(name='Rock') +>>> roll = Group.objects.create(name='Roll') + +# We start out by making sure that the Group 'rock' has no members. +>>> rock.members.all() +[] + +# To make Jim a member of Group Rock, simply create a Membership object. +>>> m1 = Membership.objects.create(person=jim, group=rock) + +# We can do the same for Jane and Rock. +>>> m2 = Membership.objects.create(person=jane, group=rock) + +# Let's check to make sure that it worked. Jane and Jim should be members of Rock. +>>> rock.members.all() +[<Person: Jane>, <Person: Jim>] + +# Now we can add a bunch more Membership objects to test with. +>>> m3 = Membership.objects.create(person=bob, group=roll) +>>> m4 = Membership.objects.create(person=jim, group=roll) +>>> m5 = Membership.objects.create(person=jane, group=roll) + +# We can get Jim's Group membership as with any ForeignKey. +>>> jim.group_set.all() +[<Group: Rock>, <Group: Roll>] + +# Querying the intermediary model works like normal. +# In this case we get Jane's membership to Rock. +>>> m = Membership.objects.get(person=jane, group=rock) +>>> m +<Membership: Jane is a member of Rock> + +# Now we set some date_joined dates for further testing. +>>> m2.invite_reason = "She was just awesome." +>>> m2.date_joined = datetime(2006, 1, 1) +>>> m2.save() + +>>> m5.date_joined = datetime(2004, 1, 1) +>>> m5.save() + +>>> m3.date_joined = datetime(2004, 1, 1) +>>> m3.save() + +# It's not only get that works. Filter works like normal as well. +>>> Membership.objects.filter(person=jim) +[<Membership: Jim is a member of Rock>, <Membership: Jim is a member of Roll>] + + +### Forward Descriptors Tests ### + +# Due to complications with adding via an intermediary model, +# the add method is not provided. +>>> rock.members.add(bob) +Traceback (most recent call last): +... +AttributeError: 'ManyRelatedManager' object has no attribute 'add' + +# Create is also disabled as it suffers from the same problems as add. +>>> rock.members.create(name='Anne') +Traceback (most recent call last): +... +AttributeError: Cannot use create() on a ManyToManyField which specifies an intermediary model. Use Membership's Manager instead. + +# Remove has similar complications, and is not provided either. +>>> rock.members.remove(jim) +Traceback (most recent call last): +... +AttributeError: 'ManyRelatedManager' object has no attribute 'remove' + +# Here we back up the list of all members of Rock. +>>> backup = list(rock.members.all()) + +# ...and we verify that it has worked. +>>> backup +[<Person: Jane>, <Person: Jim>] + +# The clear function should still work. +>>> rock.members.clear() + +# Now there will be no members of Rock. +>>> rock.members.all() +[] + +# Assignment should not work with models specifying a through model for many of +# the same reasons as adding. +>>> rock.members = backup +Traceback (most recent call last): +... +AttributeError: Cannot set values on a ManyToManyField which specifies an intermediary model. Use Membership's Manager instead. + +# Let's re-save those instances that we've cleared. +>>> m1.save() +>>> m2.save() + +# Verifying that those instances were re-saved successfully. +>>> rock.members.all() +[<Person: Jane>, <Person: Jim>] + + +### Reverse Descriptors Tests ### + +# Due to complications with adding via an intermediary model, +# the add method is not provided. +>>> bob.group_set.add(rock) +Traceback (most recent call last): +... +AttributeError: 'ManyRelatedManager' object has no attribute 'add' + +# Create is also disabled as it suffers from the same problems as add. +>>> bob.group_set.create(name='Funk') +Traceback (most recent call last): +... +AttributeError: Cannot use create() on a ManyToManyField which specifies an intermediary model. Use Membership's Manager instead. + +# Remove has similar complications, and is not provided either. +>>> jim.group_set.remove(rock) +Traceback (most recent call last): +... +AttributeError: 'ManyRelatedManager' object has no attribute 'remove' + +# Here we back up the list of all of Jim's groups. +>>> backup = list(jim.group_set.all()) +>>> backup +[<Group: Rock>, <Group: Roll>] + +# The clear function should still work. +>>> jim.group_set.clear() + +# Now Jim will be in no groups. +>>> jim.group_set.all() +[] + +# Assignment should not work with models specifying a through model for many of +# the same reasons as adding. +>>> jim.group_set = backup +Traceback (most recent call last): +... +AttributeError: Cannot set values on a ManyToManyField which specifies an intermediary model. Use Membership's Manager instead. + +# Let's re-save those instances that we've cleared. +>>> m1.save() +>>> m4.save() + +# Verifying that those instances were re-saved successfully. +>>> jim.group_set.all() +[<Group: Rock>, <Group: Roll>] + +### Custom Tests ### + +# Let's see if we can query through our second relationship. +>>> rock.custom_members.all() +[] + +# We can query in the opposite direction as well. +>>> bob.custom.all() +[] + +# Let's create some membership objects in this custom relationship. +>>> cm1 = CustomMembership.objects.create(person=bob, group=rock) +>>> cm2 = CustomMembership.objects.create(person=jim, group=rock) + +# If we get the number of people in Rock, it should be both Bob and Jim. +>>> rock.custom_members.all() +[<Person: Bob>, <Person: Jim>] + +# Bob should only be in one custom group. +>>> bob.custom.all() +[<Group: Rock>] + +# Let's make sure our new descriptors don't conflict with the FK related_name. +>>> bob.custom_person_related_name.all() +[<CustomMembership: Bob is a member of Rock>] + +### SELF-REFERENTIAL TESTS ### + +# Let's first create a person who has no friends. +>>> tony = PersonSelfRefM2M.objects.create(name="Tony") +>>> tony.friends.all() +[] + +# Now let's create another person for Tony to be friends with. +>>> chris = PersonSelfRefM2M.objects.create(name="Chris") +>>> f = Friendship.objects.create(first=tony, second=chris, date_friended=datetime.now()) + +# Tony should now show that Chris is his friend. +>>> tony.friends.all() +[<PersonSelfRefM2M: Chris>] + +# But we haven't established that Chris is Tony's Friend. +>>> chris.friends.all() +[] + +# So let's do that now. +>>> f2 = Friendship.objects.create(first=chris, second=tony, date_friended=datetime.now()) + +# Having added Chris as a friend, let's make sure that his friend set reflects +# that addition. +>>> chris.friends.all() +[<PersonSelfRefM2M: Tony>] + +# Chris gets mad and wants to get rid of all of his friends. +>>> chris.friends.clear() + +# Now he should not have any more friends. +>>> chris.friends.all() +[] + +# Since this isn't a symmetrical relation, Tony's friend link still exists. +>>> tony.friends.all() +[<PersonSelfRefM2M: Chris>] + + + +### QUERY TESTS ### + +# We can query for the related model by using its attribute name (members, in +# this case). +>>> Group.objects.filter(members__name='Bob') +[<Group: Roll>] + +# To query through the intermediary model, we specify its model name. +# In this case, membership. +>>> Group.objects.filter(membership__invite_reason="She was just awesome.") +[<Group: Rock>] + +# If we want to query in the reverse direction by the related model, use its +# model name (group, in this case). +>>> Person.objects.filter(group__name="Rock") +[<Person: Jane>, <Person: Jim>] + +# If the m2m field has specified a related_name, using that will work. +>>> Person.objects.filter(custom__name="Rock") +[<Person: Bob>, <Person: Jim>] + +# To query through the intermediary model in the reverse direction, we again +# specify its model name (membership, in this case). +>>> Person.objects.filter(membership__invite_reason="She was just awesome.") +[<Person: Jane>] + +# Let's see all of the groups that Jane joined after 1 Jan 2005: +>>> Group.objects.filter(membership__date_joined__gt=datetime(2005, 1, 1), membership__person =jane) +[<Group: Rock>] + +# Queries also work in the reverse direction: Now let's see all of the people +# that have joined Rock since 1 Jan 2005: +>>> Person.objects.filter(membership__date_joined__gt=datetime(2005, 1, 1), membership__group=rock) +[<Person: Jane>, <Person: Jim>] + +# Conceivably, queries through membership could return correct, but non-unique +# querysets. To demonstrate this, we query for all people who have joined a +# group after 2004: +>>> Person.objects.filter(membership__date_joined__gt=datetime(2004, 1, 1)) +[<Person: Jane>, <Person: Jim>, <Person: Jim>] + +# Jim showed up twice, because he joined two groups ('Rock', and 'Roll'): +>>> [(m.person.name, m.group.name) for m in +... Membership.objects.filter(date_joined__gt=datetime(2004, 1, 1))] +[(u'Jane', u'Rock'), (u'Jim', u'Rock'), (u'Jim', u'Roll')] + +# QuerySet's distinct() method can correct this problem. +>>> Person.objects.filter(membership__date_joined__gt=datetime(2004, 1, 1)).distinct() +[<Person: Jane>, <Person: Jim>] +"""}
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