an appropriate group_by_expression is required for MySQL-5.0.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@25755 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Catalog/tests/testERP5Catalog.py

@@ -3813,6 +3813,7 @@ VALUES
     portal_catalog = self.getCatalogTool()
     res = portal_catalog.searchResults(
       select_expression='count(DISTINCT catalog.reference) AS count_reference',
+      group_by_expression='catalog.reference',
     )
     self.assertEquals(1, len(res))