fix precedence of ~ operator in Q objects

src/infi/clickhouse_orm/query.py

@@ -209,10 +209,10 @@ class Q(object):
 
     @classmethod
     def _construct_from(cls, l_child, r_child, mode):
-        if mode == l_child._mode:
+        if mode == l_child._mode and not l_child._negate:
             q = deepcopy(l_child)
             q._children.append(deepcopy(r_child))
-        elif mode == r_child._mode:
+        elif mode == r_child._mode and not r_child._negate:
             q = deepcopy(r_child)
             q._children.append(deepcopy(l_child))
         else:

tests/test_querysets.py

@@ -302,6 +302,18 @@ class QuerySetTestCase(TestCaseWithData):
         self.assertEqual(qs.conditions_as_sql(),
                          "(first_name = 'a') AND (greater(`height`, 1.7)) AND (last_name = 'b')")
 
+    def test_precedence_of_negation(self):
+        p = ~Q(first_name='a')
+        q = Q(last_name='b')
+        r = p & q
+        self.assertEqual(r.to_sql(Person), "(last_name = 'b') AND (NOT (first_name = 'a'))")
+        r = q & p
+        self.assertEqual(r.to_sql(Person), "(last_name = 'b') AND (NOT (first_name = 'a'))")
+        r = q | p
+        self.assertEqual(r.to_sql(Person), "(last_name = 'b') OR (NOT (first_name = 'a'))")
+        r = ~q & p
+        self.assertEqual(r.to_sql(Person), "(NOT (last_name = 'b')) AND (NOT (first_name = 'a'))")
+
     def test_invalid_filter(self):
         qs = Person.objects_in(self.database)
         with self.assertRaises(TypeError):