diff --git a/src/Libs/ModelMySQL.php b/src/Libs/ModelMySQL.php
index 27ddcd0..a6db52f 100644
--- a/src/Libs/ModelMySQL.php
+++ b/src/Libs/ModelMySQL.php
@@ -196,7 +196,8 @@ class ModelMySQL {
 
         foreach($properties as $property) {
             $att = $property->name;
-            $result[$att] = $this->$att;
+            $result[$att] = isset($this->$att)
+                          ? $this->$att : null;
         }
 
         foreach (static::$ignoreSave as $del) {
@@ -204,7 +205,8 @@ class ModelMySQL {
         }
 
         foreach (static::$forceSave as $value) {
-            $result[$value] = $this->$value;
+            $result[$value] = isset($this->$value)
+                            ? $this->$value: null;
         }
 
         return $result;