From 15793309e16dcdf5de17594eaef1962a7c35ce31 Mon Sep 17 00:00:00 2001
From: Ramiro Morales <cramm0@gmail.com>
Date: Sat, 21 May 2011 13:12:23 +0000
Subject: [PATCH] Fixed #14476 -- Fixed resolution of automatically generated
 annotation names so e.g. filtering based on them works. Thanks dirleyls for
 the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16252 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/db/models/sql/query.py                 | 16 +++++------
 .../aggregation_regress/tests.py              | 27 +++++++++++++++++++
 2 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index 27c6859c61..99663b646b 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -1053,14 +1053,14 @@ class Query(object):
             value = SQLEvaluator(value, self)
             having_clause = value.contains_aggregate
 
-        if parts[0] in self.aggregates:
-            aggregate = self.aggregates[parts[0]]
-            entry = self.where_class()
-            entry.add((aggregate, lookup_type, value), AND)
-            if negate:
-                entry.negate()
-            self.having.add(entry, connector)
-            return
+        for alias, aggregate in self.aggregates.items():
+            if alias in (parts[0], LOOKUP_SEP.join(parts)):
+                entry = self.where_class()
+                entry.add((aggregate, lookup_type, value), AND)
+                if negate:
+                    entry.negate()
+                self.having.add(entry, connector)
+                return
 
         opts = self.get_meta()
         alias = self.get_initial_alias()
diff --git a/tests/regressiontests/aggregation_regress/tests.py b/tests/regressiontests/aggregation_regress/tests.py
index 14104210af..15692b6422 100644
--- a/tests/regressiontests/aggregation_regress/tests.py
+++ b/tests/regressiontests/aggregation_regress/tests.py
@@ -827,3 +827,30 @@ class AggregationTests(TestCase):
             Book.objects.aggregate(Variance('price', sample=True)),
             {'price__variance': Approximate(700.53, 2)}
         )
+
+    def test_filtering_by_annotation_name(self):
+        # Regression test for #14476
+
+        # The name of the explicitly provided annotation name in this case
+        # poses no problem
+        qs = Author.objects.annotate(book_cnt=Count('book')).filter(book_cnt=2)
+        self.assertQuerysetEqual(
+            qs,
+            ['Peter Norvig'],
+            lambda b: b.name
+        )
+        # Neither in this case
+        qs = Author.objects.annotate(book_count=Count('book')).filter(book_count=2)
+        self.assertQuerysetEqual(
+            qs,
+            ['Peter Norvig'],
+            lambda b: b.name
+        )
+        # This case used to fail because the ORM couldn't resolve the
+        # automatically generated annotation name `book__count`
+        qs = Author.objects.annotate(Count('book')).filter(book__count=2)
+        self.assertQuerysetEqual(
+            qs,
+            ['Peter Norvig'],
+            lambda b: b.name
+        )