diff --git a/Westdc/Db/Dbh.php b/Westdc/Db/Dbh.php
index 431a381..a9ad439 100644
--- a/Westdc/Db/Dbh.php
+++ b/Westdc/Db/Dbh.php
@@ -25,7 +25,7 @@ class Dbh
 		foreach($data as $k=>$v)
 		{
 			$fields[] = '"'.$k.'"';
-			if(is_int($v) || is_float($v) || is_bool($v))
+			if(is_int($v) || is_float($v) || is_bool($v) || $v === "NULL")
 			{
 				$datas[] = $v;
 			}else{