diff --git a/interface/lib/classes/tform.inc.php b/interface/lib/classes/tform.inc.php
index 11adc15b54edbd6c25818eabbbe5fea6e7111ef1..68104191a77abd77437830a629f6ae2f246a68b9 100644
--- a/interface/lib/classes/tform.inc.php
+++ b/interface/lib/classes/tform.inc.php
@@ -865,6 +865,8 @@ class tform {
                                 $app->error("Primary ID fehlt!");
                         }
 					}
+					//* return a empty string if there is nothing to update
+					if(trim($sql_update) == '') $sql = '';
                 }
                 
                 return $sql;