diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index 51e9d43a7e4cbbc4e659af34ba7b70d68c437e3b..65d66fdb1dbb19b0aa8d4e758e9a80be9ca42ad9 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -1798,7 +1798,7 @@ int32_t validateOneTag(SSqlCmd* pCmd, TAOS_FIELD* pTagField) {
   SSchema* pSchema = tscGetTableSchema(pTableMeta);
 
   for (int32_t i = 0; i < numOfTags + numOfCols; ++i) {
-    if (strncasecmp(pTagField->name, pSchema[i].name, sizeof(pTagField->name) - 1) == 0) {
+    if (strncmp(pTagField->name, pSchema[i].name, sizeof(pTagField->name) - 1) == 0) {
       //return tscErrorMsgWithCode(TSDB_CODE_TSC_DUP_COL_NAMES, tscGetErrorMsgPayload(pCmd), pTagField->name, NULL);
       return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), "duplicated column names");
     }
@@ -1866,7 +1866,7 @@ static bool has(SArray* pFieldList, int32_t startIdx, const char* name) {
   size_t numOfCols = taosArrayGetSize(pFieldList);
   for (int32_t j = startIdx; j < numOfCols; ++j) {
     TAOS_FIELD* field = taosArrayGet(pFieldList, j);
-    if (strncasecmp(name, field->name, sizeof(field->name) - 1) == 0) return true;
+    if (strncmp(name, field->name, sizeof(field->name) - 1) == 0) return true;
   }
 
   return false;
@@ -3953,7 +3953,7 @@ static int16_t doGetColumnIndex(SQueryInfo* pQueryInfo, int32_t index, SStrToken
       continue;
     }
 
-    if (strncasecmp(pSchema[i].name, pToken->z, pToken->n) == 0) {
+    if (strncmp(pSchema[i].name, pToken->z, pToken->n) == 0) {
       columnIndex = i;
       break;
     }
@@ -3974,7 +3974,7 @@ int32_t doGetColumnIndexByName(SStrToken* pToken, SQueryInfo* pQueryInfo, SColum
   if (isTablenameToken(pToken)) {
     pIndex->columnIndex = TSDB_TBNAME_COLUMN_INDEX;
   } else if (strlen(DEFAULT_PRIMARY_TIMESTAMP_COL_NAME) == pToken->n &&
-            strncasecmp(pToken->z, DEFAULT_PRIMARY_TIMESTAMP_COL_NAME, pToken->n) == 0) {
+            strncmp(pToken->z, DEFAULT_PRIMARY_TIMESTAMP_COL_NAME, pToken->n) == 0) {
     pIndex->columnIndex = PRIMARYKEY_TIMESTAMP_COL_INDEX; // just make runtime happy, need fix java test case InsertSpecialCharacterJniTest
   } else if (isTimeWindowToken(pToken, &tsWinColumnIndex)) {
     pIndex->columnIndex = tsWinColumnIndex;
diff --git a/src/common/src/tname.c b/src/common/src/tname.c
index 97062cf3dd1279158315c55a4ee96f332e59f7ac..521dcffa6c018a00e7485d15ee9e5799054bdba5 100644
--- a/src/common/src/tname.c
+++ b/src/common/src/tname.c
@@ -312,7 +312,7 @@ static bool doValidateSchema(SSchema* pSchema, int32_t numOfCols, int32_t maxLen
 
     // 3. valid column names
     for (int32_t j = i + 1; j < numOfCols; ++j) {
-      if (strncasecmp(pSchema[i].name, pSchema[j].name, sizeof(pSchema[i].name) - 1) == 0) {
+      if (strncmp(pSchema[i].name, pSchema[j].name, sizeof(pSchema[i].name) - 1) == 0) {
         return false;
       }
     }
diff --git a/src/mnode/src/mnodeTable.c b/src/mnode/src/mnodeTable.c
index c46230ac459f89ea9cacde48f7d05087f791e6bd..9a4ed705f8d9e25c7c2fa8130b0584be60b98ccd 100644
--- a/src/mnode/src/mnodeTable.c
+++ b/src/mnode/src/mnodeTable.c
@@ -2362,7 +2362,7 @@ static int32_t mnodeProcessDropChildTableMsg(SMnodeMsg *pMsg) {
 static int32_t mnodeFindNormalTableColumnIndex(SCTableObj *pTable, char *colName) {
   SSchema *schema = (SSchema *) pTable->schema;
   for (int32_t col = 0; col < pTable->numOfColumns; col++) {
-    if (strcasecmp(schema[col].name, colName) == 0) {
+    if (strcmp(schema[col].name, colName) == 0) {
       return col;
     }
   }
diff --git a/tests/develop-test/0-others/TD-12435.py b/tests/develop-test/0-others/TD-12435.py
index 085566d51d43f074faefc71d3dddf258f35bb019..4610845153afbaa7ddce9999164315249b3dcc32 100644
--- a/tests/develop-test/0-others/TD-12435.py
+++ b/tests/develop-test/0-others/TD-12435.py
@@ -34,7 +34,7 @@ class TDTestCase:
         tdSql.prepare()
 
         print("============== STEP 1 ===== prepare data & validate json string")
-        tdSql.execute("create table if not exists st(ts timestamp, dataInt int)")
+        tdSql.execute("create table if not exists st(ts timestamp, `dataInt` int)")
         tdSql.execute("create table st_from_sub as select avg(`dataInt`) from st interval(1m)")
         tdSql.query("describe st_from_sub")
         tdSql.checkData(1, 0, 'avg__dataInt__')