From de9942a6673cfbe442abdfabc1e8f7c0a652ef5b Mon Sep 17 00:00:00 2001 From: Luke Plant Date: Tue, 28 Feb 2012 19:34:04 +0000 Subject: [PATCH] Fixed #17668 - prefetch_related does not work in in_bulk Thanks to gurets for the report, and akaariai for the initial patch. git-svn-id: http://code.djangoproject.com/svn/django/trunk@17600 bcc190cf-cafb-0310-a4f2-bffc1f526a37 --- django/db/models/query.py | 2 +- docs/ref/models/querysets.txt | 6 ++++++ tests/modeltests/prefetch_related/tests.py | 13 +++++++++++++ 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/django/db/models/query.py b/django/db/models/query.py index 41c24c7a58..08fda78332 100644 --- a/django/db/models/query.py +++ b/django/db/models/query.py @@ -485,7 +485,7 @@ class QuerySet(object): qs = self._clone() qs.query.add_filter(('pk__in', id_list)) qs.query.clear_ordering(force_empty=True) - return dict([(obj._get_pk_val(), obj) for obj in qs.iterator()]) + return dict([(obj._get_pk_val(), obj) for obj in qs]) def delete(self): """ diff --git a/docs/ref/models/querysets.txt b/docs/ref/models/querysets.txt index 4d6b9bc533..13504f41cf 100644 --- a/docs/ref/models/querysets.txt +++ b/docs/ref/models/querysets.txt @@ -871,6 +871,9 @@ could be generated, which, depending on the database, might have performance problems of its own when it comes to parsing or executing the SQL query. Always profile for your use case! +Note that if you use ``iterator()`` to run the query, ``prefetch_related()`` +calls will be ignored since these two optimizations do not make sense together. + extra ~~~~~ @@ -1430,6 +1433,9 @@ performance and a significant reduction in memory. Note that using ``iterator()`` on a ``QuerySet`` which has already been evaluated will force it to evaluate again, repeating the query. +Also, use of ``iterator()`` causes previous ``prefetch_related()`` calls to be +ignored since these two optimizations do not make sense together. + latest ~~~~~~ diff --git a/tests/modeltests/prefetch_related/tests.py b/tests/modeltests/prefetch_related/tests.py index 4c51a83bd9..382aed68b4 100644 --- a/tests/modeltests/prefetch_related/tests.py +++ b/tests/modeltests/prefetch_related/tests.py @@ -470,3 +470,16 @@ class NullableTest(TestCase): for e in qs2] self.assertEqual(co_serfs, co_serfs2) + + def test_in_bulk(self): + """ + In-bulk does correctly prefetch objects by not using .iterator() + directly. + """ + boss1 = Employee.objects.create(name="Peter") + boss2 = Employee.objects.create(name="Jack") + with self.assertNumQueries(2): + # Check that prefetch is done and it does not cause any errors. + bulk = Employee.objects.prefetch_related('serfs').in_bulk([boss1.pk, boss2.pk]) + for b in bulk.values(): + list(b.serfs.all())