From f7ca97224a7182a01ebb19325aef1ce512f9b855 Mon Sep 17 00:00:00 2001
From: kiki <kiki@Mars.(none)>
Date: Thu, 6 Jun 2013 22:27:01 +0800
Subject: [PATCH] fix Isnull

---
 .../java/com/alibaba/druid/sql/visitor/functions/Isnull.java    | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/main/java/com/alibaba/druid/sql/visitor/functions/Isnull.java b/src/main/java/com/alibaba/druid/sql/visitor/functions/Isnull.java
index 43e6056426..dc2f388f30 100644
--- a/src/main/java/com/alibaba/druid/sql/visitor/functions/Isnull.java
+++ b/src/main/java/com/alibaba/druid/sql/visitor/functions/Isnull.java
@@ -40,6 +40,8 @@ public class Isnull implements Function {
         Object itemValue = condition.getAttributes().get(EVAL_VALUE);
         if (itemValue == EVAL_VALUE_NULL) {
             return Boolean.TRUE;
+        } else if (itemValue == null) {
+            return null;
         } else {
             return Boolean.FALSE;
         }