From 9cdd49c1e0cbe8621d162190c43284548e4b0002 Mon Sep 17 00:00:00 2001
From: Jacob Kaplan-Moss <jacob@jacobian.org>
Date: Mon, 27 Feb 2006 22:51:36 +0000
Subject: [PATCH] Added QuerySet.exclude() which does the opposite of
 QuerySet.filter().  As a side effect, the "ne" lookup type no longer exists. 
 This fixes #966.

git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@2422 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/db/backends/ado_mssql/base.py  |  1 -
 django/db/backends/mysql/base.py      |  1 -
 django/db/backends/postgresql/base.py |  1 -
 django/db/backends/sqlite3/base.py    |  1 -
 django/db/models/manager.py           |  3 +++
 django/db/models/query.py             | 19 +++++++++++++++++--
 tests/modeltests/lookup/models.py     |  8 ++++++++
 7 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/django/db/backends/ado_mssql/base.py b/django/db/backends/ado_mssql/base.py
index 7c54c7b8be..b4caebd412 100644
--- a/django/db/backends/ado_mssql/base.py
+++ b/django/db/backends/ado_mssql/base.py
@@ -119,7 +119,6 @@ OPERATOR_MAPPING = {
     'iexact': 'LIKE %s',
     'contains': 'LIKE %s',
     'icontains': 'LIKE %s',
-    'ne': '!= %s',
     'gt': '> %s',
     'gte': '>= %s',
     'lt': '< %s',
diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index c4cd36606b..04d027e148 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -132,7 +132,6 @@ OPERATOR_MAPPING = {
     'iexact': 'LIKE %s',
     'contains': 'LIKE BINARY %s',
     'icontains': 'LIKE %s',
-    'ne': '!= %s',
     'gt': '> %s',
     'gte': '>= %s',
     'lt': '< %s',
diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index 4b186975eb..47fb8e621c 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -107,7 +107,6 @@ OPERATOR_MAPPING = {
     'iexact': 'ILIKE %s',
     'contains': 'LIKE %s',
     'icontains': 'ILIKE %s',
-    'ne': '!= %s',
     'gt': '> %s',
     'gte': '>= %s',
     'lt': '< %s',
diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index 841185c8dd..5b57925256 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -131,7 +131,6 @@ OPERATOR_MAPPING = {
     'iexact': "LIKE %s ESCAPE '\\'",
     'contains': "LIKE %s ESCAPE '\\'",
     'icontains': "LIKE %s ESCAPE '\\'",
-    'ne': '!= %s',
     'gt': '> %s',
     'gte': '>= %s',
     'lt': '< %s',
diff --git a/django/db/models/manager.py b/django/db/models/manager.py
index f266d06827..e21af1ada5 100644
--- a/django/db/models/manager.py
+++ b/django/db/models/manager.py
@@ -69,6 +69,9 @@ class Manager(object):
     def filter(self, *args, **kwargs):
         return self.get_query_set().filter(*args, **kwargs)
 
+    def exclude(self, *args, **kwargs):
+        return self.get_query_set().exclude(*args, **kwargs)
+
     def in_bulk(self, *args, **kwargs):
         return self.get_query_set().in_bulk(*args, **kwargs)
 
diff --git a/django/db/models/query.py b/django/db/models/query.py
index 9c4a83f0c3..cfd86892fd 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -244,9 +244,16 @@ class QuerySet(object):
 
     def filter(self, *args, **kwargs):
         "Returns a new QuerySet instance with the args ANDed to the existing set."
+        return self._filter_or_exclude(Q, *args, **kwargs)    
+        
+    def exclude(self, *args, **kwargs):
+        "Returns a new QuerySet instance with NOT (arsg) ANDed to the existing set."
+        return self._filter_or_exclude(QNot, *args, **kwargs)
+        
+    def _filter_or_exclude(self, qtype, *args, **kwargs):
         clone = self._clone()
         if len(kwargs) > 0:
-            clone._filters = clone._filters & Q(**kwargs)
+            clone._filters = clone._filters & qtype(**kwargs)
         if len(args) > 0:
             clone._filters = clone._filters & reduce(operator.and_, args)
         return clone
@@ -490,7 +497,7 @@ class QOr(QOperator):
         else:
             raise TypeError, other
 
-class Q:
+class Q(object):
     "Encapsulates queries as objects that can be combined logically."
     def __init__(self, **kwargs):
         self.kwargs = kwargs
@@ -504,6 +511,14 @@ class Q:
     def get_sql(self, opts):
         return parse_lookup(self.kwargs.items(), opts)
 
+class QNot(Q):
+    "Encapsulates NOT (...) queries as objects"
+    
+    def get_sql(self, opts):
+        tables, joins, where, params = super(QNot, self).get_sql(opts)
+        where2 = ['(NOT (%s))' % " AND ".join(where)]
+        return tables, joins, where2, params
+
 def get_where_clause(lookup_type, table_prefix, field_name, value):
     if table_prefix.endswith('.'):
         table_prefix = backend.quote_name(table_prefix[:-1])+'.'
diff --git a/tests/modeltests/lookup/models.py b/tests/modeltests/lookup/models.py
index cc089493d5..2aaf626e36 100644
--- a/tests/modeltests/lookup/models.py
+++ b/tests/modeltests/lookup/models.py
@@ -170,4 +170,12 @@ Article 1
 [Article% with percent sign, Article_ with underscore, Article 5, Article 6, Article 4, Article 2, Article 3, Article 7, Article 1]
 >>> Article.objects.filter(headline__startswith='Article%')
 [Article% with percent sign]
+
+# exclude() is the opposite of filter() when doing lookups:
+>>> Article.objects.filter(headline__contains='Article').exclude(headline__contains='with')
+[Article 5, Article 6, Article 4, Article 2, Article 3, Article 7, Article 1]
+>>> Article.objects.exclude(headline__startswith="Article_")
+[Article% with percent sign, Article 5, Article 6, Article 4, Article 2, Article 3, Article 7, Article 1]
+>>> Article.objects.exclude(headline="Article 7")
+[Article% with percent sign, Article_ with underscore, Article 5, Article 6, Article 4, Article 2, Article 3, Article 1]cl
 """