Ticket #4858: 4858.2.patch

django/db/models/query.py

@@ -752 +752 @@
-    def __or__(self, other):
-        return QOr(self, other)
-
+    def __invert__(self):
+        return QNot(self)
+
-    def get_sql(self, opts):
-        return parse_lookup(self.kwargs.items(), opts)
-
@@ -761 +764 @@
-        "Creates a negation of the q object passed in."
-        self.q = q
-
+    def __invert__(self):
+        "Returns the inner, non-negated q object"
+        return self.q
+
-    def get_sql(self, opts):
-        try:
-            joins, where, params = self.q.get_sql(opts)

tests/modeltests/or_lookups/models.py

@@ -92 +92 @@
->>> Article.objects.filter(Q(headline__contains='bye'), headline__startswith='Hello')
-[<Article: Hello and goodbye>]
-
+# Q objects can be negated (NOT)
+>>> Article.objects.filter(Q(pk=1) | ~Q(pk=2))
+[<Article: Hello>, <Article: Hello and goodbye>]
+
+>>> Article.objects.filter(~Q(pk=1) & ~Q(pk=2))                                                                        
+[<Article: Hello and goodbye>]
+
+# This allows for more complex queries than filter() and exclude() alone would allow
+>>> Article.objects.filter(Q(pk=1) & (~Q(pk=2) | Q(pk=3)))                                                             
+[<Article: Hello>]
+
-# Try some arg queries with operations other than get_list
->>> Article.objects.get(Q(headline__startswith='Hello'), Q(headline__contains='bye'))
-<Article: Hello and goodbye>

docs/db-api.txt

@@ -1411 +1411 @@
-You can compose statements of arbitrary complexity by combining ``Q`` objects
-with the ``&`` and ``|`` operators. You can also use parenthetical grouping.
-
+``Q`` objects can also be negated using the ``~`` operator, allowing for ``OR``
+lookups that combine both a normal query and a negated (``NOT``) query::
+
+    Q(question__startswith='Who') | ~Q(pub_date__year=2005)
+
-Each lookup function that takes keyword-arguments (e.g. ``filter()``,
-``exclude()``, ``get()``) can also be passed one or more ``Q`` objects as
-positional (not-named) arguments. If you provide multiple ``Q`` object