only include a WHERE statement into the query when at least one filter part is present

Author: s3inlc

src/dba/AbstractModelFactory.class.php

@@ -746,6 +746,9 @@ private function applyFilters(&$vals, $filters) {
         array_push($vals, $v);
       }
     }
+    if (sizeof($parts) == 0) {
+      return "";
+    }
     return " WHERE " . implode(" AND ", $parts);
   }