From e47cc781d844eea72e677d1d212b2dfd1b0c9225 Mon Sep 17 00:00:00 2001
From: Malcolm Tredinnick <malcolm.tredinnick@gmail.com>
Date: Thu, 11 Sep 2008 02:00:27 +0000
Subject: [PATCH] A bug from queryset-refactor days: although the Query class
 has "group_by" and "having" attributes, only the former was included in the
 resulting SQL, meaning subclasses had to completely duplicate Query.as_sql()
 if they were using any kind of grouping filtering on the results.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9007 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/db/models/sql/query.py           | 23 +++++++++++++++++++++++
 tests/regressiontests/queries/models.py | 13 +++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index ceaf65cd4d..b4525f1075 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -292,6 +292,11 @@ class Query(object):
             grouping = self.get_grouping()
             result.append('GROUP BY %s' % ', '.join(grouping))
 
+        if self.having:
+            having, h_params = self.get_having()
+            result.append('HAVING %s' % ', '.join(having))
+            params.extend(h_params)
+
         if ordering:
             result.append('ORDER BY %s' % ', '.join(ordering))
 
@@ -573,6 +578,24 @@ class Query(object):
                 result.append(str(col))
         return result
 
+    def get_having(self):
+        """
+        Returns a tuple representing the SQL elements in the "having" clause.
+        By default, the elements of self.having have their as_sql() method
+        called or are returned unchanged (if they don't have an as_sql()
+        method).
+        """
+        result = []
+        params = []
+        for elt in self.having:
+            if hasattr(elt, 'as_sql'):
+                sql, params = elt.as_sql()
+                result.append(sql)
+                params.extend(params)
+            else:
+                result.append(elt)
+        return result, params
+
     def get_ordering(self):
         """
         Returns list representing the SQL elements in the "order by" clause.
diff --git a/tests/regressiontests/queries/models.py b/tests/regressiontests/queries/models.py
index aa1fa1edfc..49b45e83fd 100644
--- a/tests/regressiontests/queries/models.py
+++ b/tests/regressiontests/queries/models.py
@@ -953,6 +953,19 @@ relations.
 >>> len([x[2] for x in q.alias_map.values() if x[2] == q.LOUTER and q.alias_refcount[x[1]]])
 1
 
+A check to ensure we don't break the internal query construction of GROUP BY
+and HAVING. These aren't supported in the public API, but the Query class knows
+about them and shouldn't do bad things.
+>>> qs = Tag.objects.values_list('parent_id', flat=True).order_by()
+>>> qs.query.group_by = ['parent_id']
+>>> qs.query.having = ['count(parent_id) > 1']
+>>> expected = [t3.parent_id, t4.parent_id]
+>>> expected.sort()
+>>> result = list(qs)
+>>> result.sort()
+>>> expected == result
+True
+
 """}
 
 # In Python 2.3 and the Python 2.6 beta releases, exceptions raised in __len__