diff --git a/src/observer/virtual_table/ob_information_kvcache_table.h b/src/observer/virtual_table/ob_information_kvcache_table.h
index 3097933d6..1d4f21e4d 100644
--- a/src/observer/virtual_table/ob_information_kvcache_table.h
+++ b/src/observer/virtual_table/ob_information_kvcache_table.h
@@ -12,9 +12,9 @@
 
 #ifndef OCEANBASE_OBSERVER_VIRTUAL_TABLE_OB_INFORMATION_KVCACHE_TABLE_
 #define OCEANBASE_OBSERVER_VIRTUAL_TABLE_OB_INFORMATION_KVCACHE_TABLE_
-
-#include "share/ob_virtual_table_scanner_iterator.h"
-#include "share/cache/ob_kv_storecache.h"
+
+#include "share/ob_virtual_table_scanner_iterator.h"
+#include "share/cache/ob_kv_storecache.h"
 #include "lib/stat/ob_di_cache.h"
 
 
diff --git a/src/sql/engine/expr/ob_expr_from_base64.cpp b/src/sql/engine/expr/ob_expr_from_base64.cpp
index 5b39fa931..992b1bb52 100644
--- a/src/sql/engine/expr/ob_expr_from_base64.cpp
+++ b/src/sql/engine/expr/ob_expr_from_base64.cpp
@@ -179,7 +179,9 @@ int ObExprFromBase64::eval_from_base64_batch(const ObExpr &expr, ObEvalCtx &ctx,
       const ObString & in_raw = arg->get_string();
       ObLength in_raw_len = in_raw.length();
       const char *buf = in_raw.ptr();
-      if (NULL == buf) {
+      if (arg->is_null()) {
+        res[j].set_null();
+      } else if (NULL == buf) {
         res[j].set_string(nullptr, 0);
       } else {
         char *output_buf = nullptr;
diff --git a/src/sql/engine/expr/ob_expr_to_base64.cpp b/src/sql/engine/expr/ob_expr_to_base64.cpp
index 3cb4a7d7c..07c12306a 100644
--- a/src/sql/engine/expr/ob_expr_to_base64.cpp
+++ b/src/sql/engine/expr/ob_expr_to_base64.cpp
@@ -172,8 +172,10 @@ int ObExprToBase64::eval_to_base64_batch(const ObExpr &expr,
       ObLength in_raw_len = in_raw.length();
       const char *buf = in_raw.ptr();
       char *output_buf = nullptr;
-      int64_t buf_len = base64_needed_encoded_length(in_raw_len);
-      if (OB_UNLIKELY(buf_len == 0)) {
+      int64_t buf_len = 0;
+      if (arg->is_null()) {
+        res[j].set_null();
+      } else if (OB_UNLIKELY((buf_len = base64_needed_encoded_length(in_raw_len)) == 0)) {
         res[j].set_string(nullptr, 0);
       } else {
         int64_t pos = 0;