Commit d5ce2dd7 authored by Anssi Kääriäinen's avatar Anssi Kääriäinen Committed by Tim Graham
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[1.8.x] Fixed #24748 -- Fixed incorrect GROUP BY on MySQL in some queries 

When the query's model had a self-referential foreign key, the
compiler.get_group_by() code incorrectly used the self-referential
foreign key's column (for example parent_id) as GROUP BY clause
when it should have used the model's primary key column (id).

Backport of adc57632 from master
parent 056a91db

django/db/models/sql/compiler.py

+5 −2
Original line number Diff line number Diff line
@@ -145,9 +145,12 @@ class SQLCompiler(object): 
            # then also add having expressions to group by.

            pk = None

            for expr in expressions:

                if (expr.output_field.primary_key and

                        getattr(expr.output_field, 'model') == self.query.model):

                # Is this a reference to query's base table primary key? If the

                # expression isn't a Col-like, then skip the expression.

                if (getattr(expr, 'target', None) == self.query.model._meta.pk and

                        getattr(expr, 'alias', None) == self.query.tables[0]):

                    pk = expr

                    break

            if pk:

                expressions = [pk] + [expr for expr in expressions if expr in having]

        return expressions

docs/releases/1.8.2.txt

+3 −0
Original line number Diff line number Diff line
@@ -17,3 +17,6 @@ Bugfixes 
* Corrected join promotion for ``Case`` expressions. For example, annotating a

  query with a  ``Case`` expression could unexpectedly filter out results

  (:ticket:`24766`).



* Fixed incorrect GROUP BY clause generation on MySQL when the query's model

  has a self-referential foreign key (:ticket:`24748`).

tests/aggregation_regress/models.py

+5 −0
Original line number Diff line number Diff line
@@ -104,3 +104,8 @@ class Bravo(models.Model): 
class Charlie(models.Model):

    alfa = models.ForeignKey(Alfa, null=True)

    bravo = models.ForeignKey(Bravo, null=True)





class SelfRefFK(models.Model):

    name = models.CharField(max_length=50)

    parent = models.ForeignKey('self', null=True, blank=True, related_name='children')

tests/aggregation_regress/tests.py

+10 −25
Original line number Diff line number Diff line
@@ -16,7 +16,7 @@ from django.utils import six 


from .models import (

    Alfa, Author, Book, Bravo, Charlie, Clues, Entries, HardbackBook, ItemTag,

    Publisher, WithManualPK,

    Publisher, SelfRefFK, WithManualPK,

)
@@ -1174,28 +1174,13 @@ class JoinPromotionTests(TestCase): 
        self.assertIn(' INNER JOIN ', str(qs.query))





class AggregationOnRelationTest(TestCase):

    def setUp(self):

        self.a = Author.objects.create(name='Anssi', age=33)

        self.p = Publisher.objects.create(name='Manning', num_awards=3)

        Book.objects.create(isbn='asdf', name='Foo', pages=10, rating=0.1, price="0.0",

                            contact=self.a, publisher=self.p, pubdate=datetime.date.today())



    def test_annotate_on_relation(self):

        qs = Book.objects.annotate(avg_price=Avg('price'), publisher_name=F('publisher__name'))

        self.assertEqual(qs[0].avg_price, 0.0)

        self.assertEqual(qs[0].publisher_name, "Manning")



    def test_aggregate_on_relation(self):

        # A query with an existing annotation aggregation on a relation should

        # succeed.

        qs = Book.objects.annotate(avg_price=Avg('price')).aggregate(

            publisher_awards=Sum('publisher__num_awards')

        )

        self.assertEqual(qs['publisher_awards'], 3)

        Book.objects.create(isbn='asdf', name='Foo', pages=10, rating=0.1, price="0.0",

                            contact=self.a, publisher=self.p, pubdate=datetime.date.today())

        qs = Book.objects.annotate(avg_price=Avg('price')).aggregate(

            publisher_awards=Sum('publisher__num_awards')

class SelfReferentialFKTests(TestCase):

    def test_ticket_24748(self):

        t1 = SelfRefFK.objects.create(name='t1')

        SelfRefFK.objects.create(name='t2', parent=t1)

        SelfRefFK.objects.create(name='t3', parent=t1)

        self.assertQuerysetEqual(

            SelfRefFK.objects.annotate(num_children=Count('children')).order_by('name'),

            [('t1', 2), ('t2', 0), ('t3', 0)],

            lambda x: (x.name, x.num_children)

        )
 
        self.assertEqual(qs['publisher_awards'], 6)