From 40c3a1c5d67eb9826b97833ea3dff6cb2559f83e Mon Sep 17 00:00:00 2001
From: yakolee <yakolyh@gmail.com>
Date: Fri, 11 Apr 2014 15:18:12 +0800
Subject: [PATCH] improve sql wall

---
 .../java/com/alibaba/druid/sql/visitor/functions/If.java     | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/alibaba/druid/sql/visitor/functions/If.java b/src/main/java/com/alibaba/druid/sql/visitor/functions/If.java
index 243f7ca1b5..a2d1f9bc8c 100644
--- a/src/main/java/com/alibaba/druid/sql/visitor/functions/If.java
+++ b/src/main/java/com/alibaba/druid/sql/visitor/functions/If.java
@@ -38,7 +38,10 @@ public class If implements Function {
         SQLExpr condition = parameters.get(0);
         condition.accept(visitor);
         Object itemValue = condition.getAttributes().get(EVAL_VALUE);
-        if (Boolean.TRUE == itemValue || (itemValue != null && !SQLEvalVisitorUtils.eq(itemValue, 0))) {
+        if (itemValue == null) {
+            return null;
+        }
+        if (Boolean.TRUE == itemValue || !SQLEvalVisitorUtils.eq(itemValue, 0)) {
             SQLExpr trueExpr = parameters.get(1);
             trueExpr.accept(visitor);
             return trueExpr.getAttributes().get(EVAL_VALUE);