=== modified file 'plugins/views_plugin_query_default.inc'
--- plugins/views_plugin_query_default.inc	2009-10-23 04:41:24 +0000
+++ plugins/views_plugin_query_default.inc	2009-10-26 21:00:37 +0000
@@ -850,7 +850,15 @@
     foreach ($this->$where as $group => $info) {
       $sub_group = $info['type'] == 'OR' ? db_or() : db_and();
       foreach ($info['conditions'] as $key => $clause) {
-        $sub_group->condition($clause['field'], $clause['value'], $clause['operator']);
+        // Allows to use only the field. This is a kind of backward compability.
+        // If value is set but operator is empty, the operator will be converted to "=".
+        // Value is checked for isset, because the value can be 0.
+        if (!isset($clause['value']) && empty($clause['operator'])) {
+          $sub_group->where($clause['field']);
+        }
+        else {
+          $sub_group->condition($clause['field'], $clause['value'], $clause['operator']);
+        }
       }
       $main_group->condition($sub_group);
     }