Commit 3fe3887a authored by Adam Chainz's avatar Adam Chainz Committed by Tim Graham
Browse files

Fixed #25377 -- Changed Count queries to execute COUNT(*) instead of COUNT('*').

parent 4d933ad4

django/db/models/aggregates.py

+2 −2
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
Classes to represent the definitions of aggregate functions.

"""

from django.core.exceptions import FieldError

from django.db.models.expressions import Func, Value

from django.db.models.expressions import Func, Star

from django.db.models.fields import FloatField, IntegerField



__all__ = [
@@ -98,7 +98,7 @@ class Count(Aggregate): 


    def __init__(self, expression, distinct=False, **extra):

        if expression == '*':

            expression = Value(expression)

            expression = Star()

        super(Count, self).__init__(

            expression, distinct='DISTINCT ' if distinct else '', output_field=IntegerField(), **extra)

django/db/models/expressions.py

+8 −0
Original line number Diff line number Diff line
@@ -593,6 +593,14 @@ class RawSQL(Expression): 
        return [self]





class Star(Expression):

    def __repr__(self):

        return "'*'"



    def as_sql(self, compiler, connection):

        return '*', []





class Random(Expression):

    def __init__(self):

        super(Random, self).__init__(output_field=fields.FloatField())

docs/releases/1.8.5.txt

+4 −0
Original line number Diff line number Diff line
@@ -32,3 +32,7 @@ Bugfixes 


* Fixed migrations crash on MySQL when adding a text or a blob field with an

  unhashable default (:ticket:`25393`).



* Changed ``Count`` queries to execute ``COUNT(*)`` instead of ``COUNT('*')``

  as versions of Django before 1.8 did (:ticket:`25377`). This may fix a

  performance regression on some databases.

tests/aggregation/tests.py

+6 −0
Original line number Diff line number Diff line
@@ -405,6 +405,12 @@ class AggregateTestCase(TestCase): 
        vals = Book.objects.aggregate(Count("rating", distinct=True))

        self.assertEqual(vals, {"rating__count": 4})



    def test_count_star(self):

        with self.assertNumQueries(1) as ctx:

            Book.objects.aggregate(n=Count("*"))

        sql = ctx.captured_queries[0]['sql']

        self.assertIn('SELECT COUNT(*) ', sql)



    def test_non_grouped_annotation_not_in_group_by(self):

        """

        An annotation not included in values() before an aggregate should be

tests/expressions/tests.py

+1 −0
Original line number Diff line number Diff line
@@ -878,6 +878,7 @@ class ReprTests(TestCase): 
    def test_aggregates(self):

        self.assertEqual(repr(Avg('a')), "Avg(F(a))")

        self.assertEqual(repr(Count('a')), "Count(F(a), distinct=False)")

        self.assertEqual(repr(Count('*')), "Count('*', distinct=False)")

        self.assertEqual(repr(Max('a')), "Max(F(a))")

        self.assertEqual(repr(Min('a')), "Min(F(a))")

        self.assertEqual(repr(StdDev('a')), "StdDev(F(a), sample=False)")