exception: fix InvalidSortKey message

Change-Id: I0e11ee6ffc56ee0399ad930fc9da49c7f16ca67b

2 files changed, 7 insertions, 1 deletions

diff --git a/oslo_db/exception.py b/oslo_db/exception.py
index 2b2df30..ffa0931 100644
--- a/oslo_db/exception.py
+++ b/oslo_db/exception.py
@@ -183,7 +183,9 @@ class DBDataError(DBError):
 class InvalidSortKey(Exception):
     """A sort key destined for database query usage is invalid."""
 
-    message = _("Sort key supplied was not valid.")
+    def __init__(self):
+        super(InvalidSortKey, self).__init__(
+            _("Sort key supplied was not valid."))
 
 
 class ColumnError(Exception):
diff --git a/oslo_db/tests/sqlalchemy/test_utils.py b/oslo_db/tests/sqlalchemy/test_utils.py
index b7a00fb..2abda34 100644
--- a/oslo_db/tests/sqlalchemy/test_utils.py
+++ b/oslo_db/tests/sqlalchemy/test_utils.py
@@ -148,6 +148,10 @@ class TestPaginateQuery(test_base.BaseTestCase):
                              ['user_id', 'project_id'],
                              sort_dirs=['asc', 'desc'])
 
+    def test_invalid_sort_key_str(self):
+        self.assertEqual("Sort key supplied was not valid.",
+                         str(exception.InvalidSortKey()))
+
     def test_paginate_query_attribute_error(self):
         sqlalchemy.asc(self.model.user_id).AndReturn('asc')
         self.query.order_by('asc').AndReturn(self.query)