diff --git a/src/main/java/com/alibaba/druid/sql/ast/expr/SQLIdentifierExpr.java b/src/main/java/com/alibaba/druid/sql/ast/expr/SQLIdentifierExpr.java
index 3e1a9a368a..c527b3ae10 100644
--- a/src/main/java/com/alibaba/druid/sql/ast/expr/SQLIdentifierExpr.java
+++ b/src/main/java/com/alibaba/druid/sql/ast/expr/SQLIdentifierExpr.java
@@ -15,6 +15,7 @@
  */
 package com.alibaba.druid.sql.ast.expr;
 
+import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLExprImpl;
 import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
@@ -57,8 +58,8 @@ public void setLowerName(String lowerName) {
         this.lowerName = lowerName;
     }
 
-    public void output(StringBuffer buf) {
-        buf.append(this.name);
+    public String toString() {
+        return SQLUtils.toSQLString(this);
     }
 
     protected void accept0(SQLASTVisitor visitor) {