Fixed django#18056 - Cleared aggregations on DateQuery.add_date_select

Cleared aggregations on add_date_select method so only distinct dates are returned when dealing with a QuerySet that contained aggregations. That would cause the query set to return repeated dates because it would look for distinct (date kind, aggregation) pairs.

Author: nmfm

django/db/models/sql/subqueries.py

@@ -8,6 +8,7 @@
 from django.db.models.sql.datastructures import Date
 from django.db.models.sql.query import Query
 from django.db.models.sql.where import AND, Constraint
+from django.utils.datastructures import SortedDict
 from django.utils.functional import Promise
 from django.utils.encoding import force_unicode
 
@@ -205,6 +206,7 @@ def add_date_select(self, field_name, lookup_type, order='ASC'):
  self.select = [select]
  self.select_fields = [None]
  self.select_related = False # See #7097.
+ self.aggregates = SortedDict() # See 18056.
  self.set_extra_mask([])
  self.distinct = True
  self.order_by = order == 'ASC' and [1] or [-1]

tests/modeltests/aggregation/tests.py

@@ -565,3 +565,23 @@ def test_annotate_values_list(self):
  (Decimal('82.8'), 1),
  ]
  )
+
+ def test_dates_with_aggregation(self):
+ """
+ Test that .dates() returns a distinct set of dates when applied to a
+ QuerySet with aggregation.
+
+ Refs #18056. Previously, .dates() would return distinct (date_kind,
+ aggregation) sets, in this case (year, num_authors), so 2008 would be
+ returned twice because there are books from 2008 with a different
+ number of authors.
+ """
+ dates = Book.objects.annotate(num_authors=Count("authors")).dates('pubdate', 'year')
+ self.assertQuerysetEqual(
+ dates, [
+ "datetime.datetime(1991, 1, 1, 0, 0)",
+ "datetime.datetime(1995, 1, 1, 0, 0)",
+ "datetime.datetime(2007, 1, 1, 0, 0)",
+ "datetime.datetime(2008, 1, 1, 0, 0)"
+ ]
+ )