From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Sat, 22 Sep 2012 20:46:29 +0000 (-0400)
Subject: - aaand actually get is/isnot to be usable with None/NULL
X-Git-Tag: rel_0_7_9~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e5d143aae3ac928626a0352fcf23e315a4a5605a;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

- aaand actually get is/isnot to be usable with None/NULL
---

diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py
index 0dd95b3369..d5cb1ff628 100644
--- a/lib/sqlalchemy/sql/expression.py
+++ b/lib/sqlalchemy/sql/expression.py
@@ -1846,10 +1846,10 @@ class _CompareMixin(ColumnOperators):
                         **kwargs
         ):
         if obj is None or isinstance(obj, _Null):
-            if op == operators.eq:
+            if op in (operators.eq, operators.is_):
                 return _BinaryExpression(self, null(), operators.is_,
                         negate=operators.isnot)
-            elif op == operators.ne:
+            elif op in (operators.ne, operators.isnot):
                 return _BinaryExpression(self, null(), operators.isnot,
                         negate=operators.is_)
             else:
@@ -2959,6 +2959,10 @@ class _Null(ColumnElement):
     def __init__(self):
         self.type = sqltypes.NULLTYPE
 
+    def compare(self, other):
+        return isinstance(other, _Null)
+
+
 class _False(ColumnElement):
     """Represent the ``false`` keyword in a SQL statement.
 
diff --git a/test/sql/test_operators.py b/test/sql/test_operators.py
index cf20189340..7ea3ade819 100644
--- a/test/sql/test_operators.py
+++ b/test/sql/test_operators.py
@@ -21,9 +21,8 @@ class DefaultColumnComparatorTest(fixtures.TestBase):
             compare_to(left)
         )
 
-    def _do_operate_test(self, operator):
+    def _do_operate_test(self, operator, right=column('right')):
         left = column('left')
-        right = column('right')
 
         assert operator(left, right).compare(
             BinaryExpression(left, right, operator)
@@ -38,6 +37,12 @@ class DefaultColumnComparatorTest(fixtures.TestBase):
     def test_plus(self):
         self._do_operate_test(operators.add)
 
+    def test_is_null(self):
+        self._do_operate_test(operators.is_, None)
+
+    def test_isnot_null(self):
+        self._do_operate_test(operators.isnot, None)
+
     def test_is(self):
         self._do_operate_test(operators.is_)