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Code Issues 32 Releases Wiki Activity

Fixed #12687 -- fixed an issue with aggregates and counts in conjunction with annotations where the QuerySet was provably empty.

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git-svn-id: http://code.djangoproject.com/svn/django/trunk@14586 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Alex Gaynor
2010-11-17 02:57:14 +00:00
parent 3e9d2f81c5
commit 4276b5197b
4 changed files with 36 additions and 4 deletions
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20
django/db/models/sql/query.py
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@@ -337,7 +337,7 @@ class Query(object):
# information but retrieves only the first row. Aggregate
# over the subquery instead.
if self.group_by is not None:
from subqueries import AggregateQuery
from django.db.models.sql.subqueries import AggregateQuery
query = AggregateQuery(self.model)
obj = self.clone()
@@ -349,7 +349,13 @@ class Query(object):
query.aggregate_select[alias] = aggregate
del obj.aggregate_select[alias]
query.add_subquery(obj, using)
try:
query.add_subquery(obj, using)
except EmptyResultSet:
return dict(
(alias, None)
for alias in query.aggregate_select
)
else:
query = self
self.select = []
@@ -382,13 +388,19 @@ class Query(object):
# If a select clause exists, then the query has already started to
# specify the columns that are to be returned.
# In this case, we need to use a subquery to evaluate the count.
from subqueries import AggregateQuery
from django.db.models.sql.subqueries import AggregateQuery
subquery = obj
subquery.clear_ordering(True)
subquery.clear_limits()
obj = AggregateQuery(obj.model)
obj.add_subquery(subquery, using=using)
try:
obj.add_subquery(subquery, using=using)
except EmptyResultSet:
# add_subquery evaluates the query, if it's an EmptyResultSet
# then there are can be no results, and therefore there the
# count is obviously 0
return 0
obj.add_count_column()
number = obj.get_aggregation(using=using)[None]