diff --git a/cpp/src/cwrapper/tsfile_cwrapper.cc b/cpp/src/cwrapper/tsfile_cwrapper.cc
index 656737dfd..0095dd139 100644
--- a/cpp/src/cwrapper/tsfile_cwrapper.cc
+++ b/cpp/src/cwrapper/tsfile_cwrapper.cc
@@ -316,7 +316,7 @@ bool tsfile_result_set_next(ResultSet result_set, ERRNO *err_code) {
                                                     const char *column_name) { \
         auto *r = static_cast<storage::TableResultSet *>(result_set);          \
         std::string column_name_(column_name);                                 \
-        return r->get_value<type>(storage::to_lower(column_name_));            \
+        return r->get_value<type>(column_name_);                               \
     }
 
 TSFILE_RESULT_SET_GET_VALUE_BY_NAME_DEF(bool);
@@ -329,7 +329,7 @@ char *tsfile_result_set_get_value_by_name_string(ResultSet result_set,
     auto *r = static_cast<storage::TableResultSet *>(result_set);
     std::string column_name_(column_name);
     common::String *ret =
-        r->get_value<common::String *>(storage::to_lower(column_name_));
+        r->get_value<common::String *>(column_name_);
     // Caller should free return's char* 's space.
     char *dup = (char *)malloc(ret->len_ + 1);
     if (dup) {
diff --git a/cpp/src/reader/table_query_executor.cc b/cpp/src/reader/table_query_executor.cc
index 6249f9e7f..97913c214 100644
--- a/cpp/src/reader/table_query_executor.cc
+++ b/cpp/src/reader/table_query_executor.cc
@@ -41,9 +41,13 @@ int TableQueryExecutor::query(const std::string &table_name,
         ret_qds = nullptr;
         return ret;
     }
+    std::vector<std::string> std_column_names(columns);
+    for (auto &column : std_column_names) {
+        to_lowercase_inplace(column);
+    }
     std::shared_ptr<ColumnMapping> column_mapping = std::make_shared<ColumnMapping>();
-    for (size_t i = 0; i < columns.size(); ++i) {
-        column_mapping->add(columns[i], static_cast<int>(i), *table_schema);
+    for (size_t i = 0; i < std_column_names.size(); ++i) {
+        column_mapping->add(std_column_names[i], static_cast<int>(i), *table_schema);
     }
     std::vector<common::TSDataType> data_types;
     data_types.reserve(columns.size());
@@ -57,7 +61,7 @@ int TableQueryExecutor::query(const std::string &table_name,
     // column_mapping.add(*measurement_filter);
 
     auto device_task_iterator = std::unique_ptr<DeviceTaskIterator>(
-        new DeviceTaskIterator(columns, table_root, column_mapping,
+        new DeviceTaskIterator(std_column_names, table_root, column_mapping,
                                meta_data_querier_, id_filter, table_schema));
 
     std::unique_ptr<TsBlockReader> tsblock_reader;
diff --git a/cpp/src/reader/table_result_set.cc b/cpp/src/reader/table_result_set.cc
index 23e35aaa0..bbadc44a5 100644
--- a/cpp/src/reader/table_result_set.cc
+++ b/cpp/src/reader/table_result_set.cc
@@ -80,7 +80,7 @@ int TableResultSet::next(bool& has_next) {
 }
 
 bool TableResultSet::is_null(const std::string& column_name) {
-    auto iter = index_lookup_.find(to_lower(column_name));
+    auto iter = index_lookup_.find(column_name);
     if (iter == index_lookup_.end()) {
         return true;
     } else {
diff --git a/cpp/src/reader/tsfile_reader.cc b/cpp/src/reader/tsfile_reader.cc
index 162fb6ad2..bf3a2db7e 100644
--- a/cpp/src/reader/tsfile_reader.cc
+++ b/cpp/src/reader/tsfile_reader.cc
@@ -97,15 +97,11 @@ int TsFileReader::query(const std::string &table_name,
     if (table_schema == nullptr) {
         return E_TABLE_NOT_EXIST;
     }
-    std::vector<std::string> columns_names_lowercase(columns_names);
-    for (auto &column_name : columns_names_lowercase) {
-        to_lowercase_inplace(column_name);
-    }
 
     std::vector<TSDataType> data_types = table_schema->get_data_types();
 
     Filter* time_filter = new TimeBetween(start_time, end_time, false);
-    ret = table_query_executor_->query(to_lower(table_name), columns_names_lowercase, time_filter, nullptr, nullptr, result_set);
+    ret = table_query_executor_->query(to_lower(table_name), columns_names, time_filter, nullptr, nullptr, result_set);
     return ret;
 }
 
diff --git a/cpp/src/utils/storage_utils.h b/cpp/src/utils/storage_utils.h
index f4d596b00..698a73031 100644
--- a/cpp/src/utils/storage_utils.h
+++ b/cpp/src/utils/storage_utils.h
@@ -19,8 +19,6 @@
 #ifndef UTILS_STORAGE_UTILS_H
 #define UTILS_STORAGE_UTILS_H
 
-#include <inttypes.h>
-#include <stdint.h>
 #include <algorithm>
 
 #include "common/datatype/value.h"
diff --git a/cpp/test/cwrapper/c_release_test.cc b/cpp/test/cwrapper/c_release_test.cc
index bb73fb9d7..0ccb0cdda 100644
--- a/cpp/test/cwrapper/c_release_test.cc
+++ b/cpp/test/cwrapper/c_release_test.cc
@@ -307,9 +307,9 @@ TEST_F(CReleaseTest, TsFileWriterMultiDataType) {
         ASSERT_EQ("device1", std::string(str_value));
         free(str_value);
         ASSERT_EQ(value, tsfile_result_set_get_value_by_name_int32_t(result_set,
-                                                                     "int32"));
+                                                                     "INT32"));
         ASSERT_EQ(value * 100, tsfile_result_set_get_value_by_name_int64_t(
-                                   result_set, "int64"));
+                                   result_set, "INT64"));
         ASSERT_EQ(value * 100.0, tsfile_result_set_get_value_by_name_float(
                                      result_set, "FLOAT"));