Ticket #16211: django-query-expression-negate.patch

django/db/models/expressions.py

@@ -20 +20 @@
     AND = '&'
     OR = '|'
 
+    # Logical operators
+    NOT = 'NOT' # unary, needs special attention in combine_expression
+
     def __init__(self, children=None, connector=None, negated=False):
         if children is not None and len(children) > 1 and connector is None:
             raise TypeError('You have to specify a connector.')
@@ -48 +51 @@
     # OPERATORS #
     #############
 
+    def __invert__(self):
+        obj = ExpressionNode([self], connector=self.NOT, negated=True)
+        return obj
+
     def __add__(self, other):
         return self._combine(other, self.ADD, False)
 

django/db/backends/__init__.py

@@ -472 +472 @@
         can vary between backends (e.g., Oracle with %% and &) and between
         subexpression types (e.g., date expressions)
         """
+        if connector == 'NOT':
+            assert len(sub_expressions) == 1
+            return 'NOT (%s)' % sub_expressions[0]
         conn = ' %s ' % connector
         return conn.join(sub_expressions)