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Fixed #29789 -- Added support for nested relations to FilteredRelation.

This commit is contained in:
matt ferrante 2020-01-06 16:44:32 -07:00 committed by Mariusz Felisiak
parent 5a3d7cf462
commit 7d6916e827
5 changed files with 336 additions and 39 deletions
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39
django/db/models/sql/query.py
View File

@ -1419,14 +1419,30 @@ class Query(BaseExpression):
def add_filtered_relation(self, filtered_relation, alias):
filtered_relation.alias = alias
lookups = dict(get_children_from_q(filtered_relation.condition))
for lookup in chain((filtered_relation.relation_name,), lookups):
lookup_parts, field_parts, _ = self.solve_lookup_type(lookup)
relation_lookup_parts, relation_field_parts, _ = self.solve_lookup_type(filtered_relation.relation_name)
if relation_lookup_parts:
raise ValueError(
"FilteredRelation's relation_name cannot contain lookups "
"(got %r)." % filtered_relation.relation_name
)
for lookup in chain(lookups):
lookup_parts, lookup_field_parts, _ = self.solve_lookup_type(lookup)
shift = 2 if not lookup_parts else 1
if len(field_parts) > (shift + len(lookup_parts)):
raise ValueError(
"FilteredRelation's condition doesn't support nested "
"relations (got %r)." % lookup
)
lookup_field_path = lookup_field_parts[:-shift]
for idx, lookup_field_part in enumerate(lookup_field_path):
if len(relation_field_parts) > idx:
if relation_field_parts[idx] != lookup_field_part:
raise ValueError(
"FilteredRelation's condition doesn't support "
"relations outside the %r (got %r)."
% (filtered_relation.relation_name, lookup)
)
else:
raise ValueError(
"FilteredRelation's condition doesn't support nested "
"relations deeper than the relation_name (got %r for "
"%r)." % (lookup, filtered_relation.relation_name)
)
self._filtered_relations[filtered_relation.alias] = filtered_relation
def names_to_path(self, names, opts, allow_many=True, fail_on_missing=False):
@ -1459,7 +1475,14 @@ class Query(BaseExpression):
field = self.annotation_select[name].output_field
elif name in self._filtered_relations and pos == 0:
filtered_relation = self._filtered_relations[name]
field = opts.get_field(filtered_relation.relation_name)
if LOOKUP_SEP in filtered_relation.relation_name:
parts = filtered_relation.relation_name.split(LOOKUP_SEP)
filtered_relation_path, field, _, _ = self.names_to_path(
parts, opts, allow_many, fail_on_missing,
)
path.extend(filtered_relation_path[:-1])
else:
field = opts.get_field(filtered_relation.relation_name)
if field is not None:
# Fields that contain one-to-many relations with a generic
# model (like a GenericForeignKey) cannot generate reverse

15
docs/ref/models/querysets.txt
View File

@ -3707,17 +3707,10 @@ operate on vegetarian pizzas.
``FilteredRelation`` doesn't support:
* Conditions that span relational fields. For example::
>>> Restaurant.objects.annotate(
... pizzas_with_toppings_startswith_n=FilteredRelation(
... 'pizzas__toppings',
... condition=Q(pizzas__toppings__name__startswith='n'),
... ),
... )
Traceback (most recent call last):
...
ValueError: FilteredRelation's condition doesn't support nested relations (got 'pizzas__toppings__name__startswith').
* :meth:`.QuerySet.only` and :meth:`~.QuerySet.prefetch_related`.
* A :class:`~django.contrib.contenttypes.fields.GenericForeignKey`
inherited from a parent model.
.. versionchanged:: 3.2
Support for nested relations was added.

3
docs/releases/3.2.txt
View File

@ -227,6 +227,9 @@ Models
* The :meth:`.QuerySet.update` method now respects the ``order_by()`` clause on
MySQL and MariaDB.
* :class:`FilteredRelation() <django.db.models.FilteredRelation>` now supports
nested relations.
Requests and Responses
~~~~~~~~~~~~~~~~~~~~~~

31
tests/filtered_relation/models.py
View File

@ -88,3 +88,34 @@ class RentalSession(models.Model):
related_query_name='rental_session',
)
state = models.CharField(max_length=7, choices=STATES, default=NEW)
class Seller(models.Model):
name = models.CharField(max_length=255)
class Currency(models.Model):
currency = models.CharField(max_length=3)
class ExchangeRate(models.Model):
rate_date = models.DateField()
from_currency = models.ForeignKey(
Currency,
models.CASCADE,
related_name='rates_from',
)
to_currency = models.ForeignKey(
Currency,
models.CASCADE,
related_name='rates_to',
)
rate = models.DecimalField(max_digits=6, decimal_places=4)
class BookDailySales(models.Model):
book = models.ForeignKey(Book, models.CASCADE, related_name='daily_sales')
sale_date = models.DateField()
currency = models.ForeignKey(Currency, models.CASCADE)
seller = models.ForeignKey(Seller, models.CASCADE)
sales = models.DecimalField(max_digits=10, decimal_places=2)

287
tests/filtered_relation/tests.py
View File

@ -1,11 +1,18 @@
from datetime import date
from decimal import Decimal
from unittest import mock
from django.db import connection, transaction
from django.db.models import Case, Count, F, FilteredRelation, Q, When
from django.db.models import (
Case, Count, DecimalField, F, FilteredRelation, Q, Sum, When,
)
from django.test import TestCase
from django.test.testcases import skipUnlessDBFeature
from .models import Author, Book, Borrower, Editor, RentalSession, Reservation
from .models import (
Author, Book, BookDailySales, Borrower, Currency, Editor, ExchangeRate,
RentalSession, Reservation, Seller,
)
class FilteredRelationTests(TestCase):
@ -279,28 +286,148 @@ class FilteredRelationTests(TestCase):
qs = Author.objects.filter(id__in=inner_qs)
self.assertSequenceEqual(qs, [self.author1])
def test_with_foreign_key_error(self):
msg = (
"FilteredRelation's condition doesn't support nested relations "
"(got 'author__favorite_books__author')."
)
with self.assertRaisesMessage(ValueError, msg):
list(Book.objects.annotate(
alice_favorite_books=FilteredRelation(
'author__favorite_books',
condition=Q(author__favorite_books__author=self.author1),
)
))
def test_nested_foreign_key(self):
qs = Author.objects.annotate(
book_editor_worked_with=FilteredRelation(
'book__editor',
condition=Q(book__title__icontains='book by'),
),
).filter(
book_editor_worked_with__isnull=False,
).select_related(
'book_editor_worked_with',
).order_by('pk', 'book_editor_worked_with__pk')
with self.assertNumQueries(1):
self.assertQuerysetEqual(qs, [
(self.author1, self.editor_a),
(self.author2, self.editor_b),
(self.author2, self.editor_b),
], lambda x: (x, x.book_editor_worked_with))
def test_with_foreign_key_on_condition_error(self):
def test_nested_foreign_key_nested_field(self):
qs = Author.objects.annotate(
book_editor_worked_with=FilteredRelation(
'book__editor',
condition=Q(book__title__icontains='book by')
),
).filter(
book_editor_worked_with__isnull=False,
).values(
'name', 'book_editor_worked_with__name',
).order_by('name', 'book_editor_worked_with__name').distinct()
self.assertSequenceEqual(qs, [
{'name': self.author1.name, 'book_editor_worked_with__name': self.editor_a.name},
{'name': self.author2.name, 'book_editor_worked_with__name': self.editor_b.name},
])
def test_nested_foreign_key_filtered_base_object(self):
qs = Author.objects.annotate(
alice_editors=FilteredRelation(
'book__editor',
condition=Q(name='Alice'),
),
).values(
'name', 'alice_editors__pk',
).order_by('name', 'alice_editors__name').distinct()
self.assertSequenceEqual(qs, [
{'name': self.author1.name, 'alice_editors__pk': self.editor_a.pk},
{'name': self.author2.name, 'alice_editors__pk': None},
])
def test_nested_m2m_filtered(self):
qs = Book.objects.annotate(
favorite_book=FilteredRelation(
'author__favorite_books',
condition=Q(author__favorite_books__title__icontains='book by')
),
).values(
'title', 'favorite_book__pk',
).order_by('title', 'favorite_book__title')
self.assertSequenceEqual(qs, [
{'title': self.book1.title, 'favorite_book__pk': self.book2.pk},
{'title': self.book1.title, 'favorite_book__pk': self.book3.pk},
{'title': self.book4.title, 'favorite_book__pk': self.book2.pk},
{'title': self.book4.title, 'favorite_book__pk': self.book3.pk},
{'title': self.book2.title, 'favorite_book__pk': None},
{'title': self.book3.title, 'favorite_book__pk': None},
])
def test_nested_chained_relations(self):
qs = Author.objects.annotate(
my_books=FilteredRelation(
'book', condition=Q(book__title__icontains='book by'),
),
preferred_by_authors=FilteredRelation(
'my_books__preferred_by_authors',
condition=Q(my_books__preferred_by_authors__name='Alice'),
),
).annotate(
author=F('name'),
book_title=F('my_books__title'),
preferred_by_author_pk=F('preferred_by_authors'),
).order_by('author', 'book_title', 'preferred_by_author_pk')
self.assertQuerysetEqual(qs, [
('Alice', 'The book by Alice', None),
('Jane', 'The book by Jane A', self.author1.pk),
('Jane', 'The book by Jane B', self.author1.pk),
], lambda x: (x.author, x.book_title, x.preferred_by_author_pk))
def test_deep_nested_foreign_key(self):
qs = Book.objects.annotate(
author_favorite_book_editor=FilteredRelation(
'author__favorite_books__editor',
condition=Q(author__favorite_books__title__icontains='Jane A'),
),
).filter(
author_favorite_book_editor__isnull=False,
).select_related(
'author_favorite_book_editor',
).order_by('pk', 'author_favorite_book_editor__pk')
with self.assertNumQueries(1):
self.assertQuerysetEqual(qs, [
(self.book1, self.editor_b),
(self.book4, self.editor_b),
], lambda x: (x, x.author_favorite_book_editor))
def test_relation_name_lookup(self):
msg = (
"FilteredRelation's condition doesn't support nested relations "
"(got 'book__editor__name__icontains')."
"FilteredRelation's relation_name cannot contain lookups (got "
"'book__title__icontains')."
)
with self.assertRaisesMessage(ValueError, msg):
list(Author.objects.annotate(
book_edited_by_b=FilteredRelation('book', condition=Q(book__editor__name__icontains='b')),
))
Author.objects.annotate(
book_title=FilteredRelation(
'book__title__icontains',
condition=Q(book__title='Poem by Alice'),
),
)
def test_condition_outside_relation_name(self):
msg = (
"FilteredRelation's condition doesn't support relations outside "
"the 'book__editor' (got 'book__author__name__icontains')."
)
with self.assertRaisesMessage(ValueError, msg):
Author.objects.annotate(
book_editor=FilteredRelation(
'book__editor',
condition=Q(book__author__name__icontains='book'),
),
)
def test_condition_deeper_relation_name(self):
msg = (
"FilteredRelation's condition doesn't support nested relations "
"deeper than the relation_name (got "
"'book__editor__name__icontains' for 'book')."
)
with self.assertRaisesMessage(ValueError, msg):
Author.objects.annotate(
book_editor=FilteredRelation(
'book',
condition=Q(book__editor__name__icontains='b'),
),
)
def test_with_empty_relation_name_error(self):
with self.assertRaisesMessage(ValueError, 'relation_name cannot be empty.'):
@ -424,3 +551,123 @@ class FilteredRelationAggregationTests(TestCase):
).distinct()
self.assertEqual(qs.count(), 1)
self.assertSequenceEqual(qs.annotate(total=Count('pk')).values('total'), [{'total': 1}])
class FilteredRelationAnalyticalAggregationTests(TestCase):
@classmethod
def setUpTestData(cls):
author = Author.objects.create(name='Author')
editor = Editor.objects.create(name='Editor')
cls.book1 = Book.objects.create(
title='Poem by Alice',
editor=editor,
author=author,
)
cls.book2 = Book.objects.create(
title='The book by Jane A',
editor=editor,
author=author,
)
cls.book3 = Book.objects.create(
title='The book by Jane B',
editor=editor,
author=author,
)
cls.seller1 = Seller.objects.create(name='Seller 1')
cls.seller2 = Seller.objects.create(name='Seller 2')
cls.usd = Currency.objects.create(currency='USD')
cls.eur = Currency.objects.create(currency='EUR')
cls.sales_date1 = date(2020, 7, 6)
cls.sales_date2 = date(2020, 7, 7)
ExchangeRate.objects.bulk_create([
ExchangeRate(
rate_date=cls.sales_date1,
from_currency=cls.usd,
to_currency=cls.eur,
rate=0.40,
),
ExchangeRate(
rate_date=cls.sales_date1,
from_currency=cls.eur,
to_currency=cls.usd,
rate=1.60,
),
ExchangeRate(
rate_date=cls.sales_date2,
from_currency=cls.usd,
to_currency=cls.eur,
rate=0.50,
),
ExchangeRate(
rate_date=cls.sales_date2,
from_currency=cls.eur,
to_currency=cls.usd,
rate=1.50,
),
ExchangeRate(
rate_date=cls.sales_date2,
from_currency=cls.usd,
to_currency=cls.usd,
rate=1.00,
),
])
BookDailySales.objects.bulk_create([
BookDailySales(
book=cls.book1,
sale_date=cls.sales_date1,
currency=cls.usd,
sales=100.00,
seller=cls.seller1,
),
BookDailySales(
book=cls.book2,
sale_date=cls.sales_date1,
currency=cls.eur,
sales=200.00,
seller=cls.seller1,
),
BookDailySales(
book=cls.book1,
sale_date=cls.sales_date2,
currency=cls.usd,
sales=50.00,
seller=cls.seller2,
),
BookDailySales(
book=cls.book2,
sale_date=cls.sales_date2,
currency=cls.eur,
sales=100.00,
seller=cls.seller2,
),
])
def test_aggregate(self):
tests = [
Q(daily_sales__sale_date__gte=self.sales_date2),
~Q(daily_sales__seller=self.seller1),
]
for condition in tests:
with self.subTest(condition=condition):
qs = Book.objects.annotate(
recent_sales=FilteredRelation('daily_sales', condition=condition),
recent_sales_rates=FilteredRelation(
'recent_sales__currency__rates_from',
condition=Q(
recent_sales__currency__rates_from__rate_date=F('recent_sales__sale_date'),
recent_sales__currency__rates_from__to_currency=self.usd,
),
),
).annotate(
sales_sum=Sum(
F('recent_sales__sales') * F('recent_sales_rates__rate'),
output_field=DecimalField(),
),
).values('title', 'sales_sum').order_by(
F('sales_sum').desc(nulls_last=True),
)
self.assertSequenceEqual(qs, [
{'title': self.book2.title, 'sales_sum': Decimal(150.00)},
{'title': self.book1.title, 'sales_sum': Decimal(50.00)},
{'title': self.book3.title, 'sales_sum': None},
])