Commit a6074e89 authored by Simon Charette's avatar Simon Charette
Browse files

Fixed #26458 -- Based Avg's default output_field resolution on its source field type. 

Thanks Tim for the review and Josh for the input.
parent 361cb7a8

django/db/models/aggregates.py

+6 −4
Original line number Diff line number Diff line
@@ -3,7 +3,7 @@ Classes to represent the definitions of aggregate functions. 
"""

from django.core.exceptions import FieldError

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

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

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



__all__ = [

    'Aggregate', 'Avg', 'Count', 'Max', 'Min', 'StdDev', 'Sum', 'Variance',
@@ -41,9 +41,11 @@ class Avg(Aggregate): 
    function = 'AVG'

    name = 'Avg'



    def __init__(self, expression, **extra):

        output_field = extra.pop('output_field', FloatField())

        super(Avg, self).__init__(expression, output_field=output_field, **extra)

    def _resolve_output_field(self):

        source_field = self.get_source_fields()[0]

        if isinstance(source_field, (IntegerField, DecimalField)):

            self._output_field = FloatField()

        super(Avg, self)._resolve_output_field()



    def as_oracle(self, compiler, connection):

        if self.output_field.get_internal_type() == 'DurationField':

tests/aggregation/tests.py

+6 −0
Original line number Diff line number Diff line
@@ -496,10 +496,16 @@ class AggregateTestCase(TestCase): 
        self.assertEqual(vals, {"num_authors__avg": Approximate(1.66, places=1)})



    def test_avg_duration_field(self):

        # Explicit `output_field`.

        self.assertEqual(

            Publisher.objects.aggregate(Avg('duration', output_field=DurationField())),

            {'duration__avg': datetime.timedelta(days=1, hours=12)}

        )

        # Implicit `output_field`.

        self.assertEqual(

            Publisher.objects.aggregate(Avg('duration')),

            {'duration__avg': datetime.timedelta(days=1, hours=12)}

        )



    def test_sum_duration_field(self):

        self.assertEqual(