1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
from django.contrib.contenttypes.models import ContentType
from django.db import models
class Relation(models.Model):
pass
class InstanceOnlyDescriptor:
def __get__(self, instance, cls=None):
if instance is None:
raise AttributeError("Instance only")
return 1
class AbstractPerson(models.Model):
# DATA fields
data_abstract = models.CharField(max_length=10)
fk_abstract = models.ForeignKey(
Relation, models.CASCADE, related_name="fk_abstract_rel"
)
# M2M fields
m2m_abstract = models.ManyToManyField(Relation, related_name="m2m_abstract_rel")
friends_abstract = models.ManyToManyField("self", symmetrical=True)
following_abstract = models.ManyToManyField(
"self", related_name="followers_abstract", symmetrical=False
)
# VIRTUAL fields
data_not_concrete_abstract = models.ForeignObject(
Relation,
on_delete=models.CASCADE,
from_fields=["abstract_non_concrete_id"],
to_fields=["id"],
related_name="fo_abstract_rel",
)
# GFK fields
content_type_abstract = models.ForeignKey(
ContentType, models.CASCADE, related_name="+"
)
object_id_abstract = models.PositiveIntegerField()
content_object_abstract = GenericForeignKey(
"content_type_abstract", "object_id_abstract"
)
# GR fields
generic_relation_abstract = GenericRelation(Relation)
class Meta:
abstract = True
@property
def test_property(self):
return 1
test_instance_only_descriptor = InstanceOnlyDescriptor()
class BasePerson(AbstractPerson):
# DATA fields
data_base = models.CharField(max_length=10)
fk_base = models.ForeignKey(Relation, models.CASCADE, related_name="fk_base_rel")
# M2M fields
m2m_base = models.ManyToManyField(Relation, related_name="m2m_base_rel")
friends_base = models.ManyToManyField("self", symmetrical=True)
following_base = models.ManyToManyField(
"self", related_name="followers_base", symmetrical=False
)
# VIRTUAL fields
data_not_concrete_base = models.ForeignObject(
Relation,
on_delete=models.CASCADE,
from_fields=["base_non_concrete_id"],
to_fields=["id"],
related_name="fo_base_rel",
)
# GFK fields
content_type_base = models.ForeignKey(ContentType, models.CASCADE, related_name="+")
object_id_base = models.PositiveIntegerField()
content_object_base = GenericForeignKey("content_type_base", "object_id_base")
# GR fields
generic_relation_base = GenericRelation(Relation)
class Person(BasePerson):
# DATA fields
data_inherited = models.CharField(max_length=10)
fk_inherited = models.ForeignKey(
Relation, models.CASCADE, related_name="fk_concrete_rel"
)
# M2M Fields
m2m_inherited = models.ManyToManyField(Relation, related_name="m2m_concrete_rel")
friends_inherited = models.ManyToManyField("self", symmetrical=True)
following_inherited = models.ManyToManyField(
"self", related_name="followers_concrete", symmetrical=False
)
# VIRTUAL fields
data_not_concrete_inherited = models.ForeignObject(
Relation,
on_delete=models.CASCADE,
from_fields=["model_non_concrete_id"],
to_fields=["id"],
related_name="fo_concrete_rel",
)
# GFK fields
content_type_concrete = models.ForeignKey(
ContentType, models.CASCADE, related_name="+"
)
object_id_concrete = models.PositiveIntegerField()
content_object_concrete = GenericForeignKey(
"content_type_concrete", "object_id_concrete"
)
# GR fields
generic_relation_concrete = GenericRelation(Relation)
class ProxyPerson(Person):
class Meta:
proxy = True
class PersonThroughProxySubclass(ProxyPerson):
pass
class Relating(models.Model):
# ForeignKey to BasePerson
baseperson = models.ForeignKey(
BasePerson, models.CASCADE, related_name="relating_baseperson"
)
baseperson_hidden = models.ForeignKey(BasePerson, models.CASCADE, related_name="+")
# ForeignKey to Person
person = models.ForeignKey(Person, models.CASCADE, related_name="relating_person")
person_hidden = models.ForeignKey(Person, models.CASCADE, related_name="+")
# ForeignKey to ProxyPerson
proxyperson = models.ForeignKey(
ProxyPerson, models.CASCADE, related_name="relating_proxyperson"
)
proxyperson_hidden = models.ForeignKey(
ProxyPerson, models.CASCADE, related_name="relating_proxyperson_hidden+"
)
# ManyToManyField to BasePerson
basepeople = models.ManyToManyField(BasePerson, related_name="relating_basepeople")
basepeople_hidden = models.ManyToManyField(BasePerson, related_name="+")
# ManyToManyField to Person
people = models.ManyToManyField(Person, related_name="relating_people")
people_hidden = models.ManyToManyField(Person, related_name="+")
# ParentListTests models
class CommonAncestor(models.Model):
pass
class FirstParent(CommonAncestor):
first_ancestor = models.OneToOneField(
CommonAncestor, models.CASCADE, primary_key=True, parent_link=True
)
class SecondParent(CommonAncestor):
second_ancestor = models.OneToOneField(
CommonAncestor, models.CASCADE, primary_key=True, parent_link=True
)
class Child(FirstParent, SecondParent):
pass
|
