_c0 can not be alias and ts will refer to hidden ts column of func

src/client/src/tscSQLParser.c

@@ -2191,7 +2191,7 @@ int32_t validateSelectNodeList(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SArray* pS
       return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg11);
     }
 
-    if(pItem->aliasName != NULL && validateColumnName(pItem->aliasName) != TSDB_CODE_SUCCESS){
+    if(pItem->aliasName != NULL && strcasecmp(pItem->aliasName, DEFAULT_PRIMARY_TIMESTAMP_COL_NAME) == 0){
       return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg11);
     }
 
@@ -2808,7 +2808,7 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
       if (functionId == TSDB_FUNC_DIFF || functionId == TSDB_FUNC_DERIVATIVE || functionId == TSDB_FUNC_CSUM) {
         SColumnIndex indexTS = {.tableIndex = index.tableIndex, .columnIndex = 0};
         SExprInfo*   pExpr = tscExprAppend(pQueryInfo, TSDB_FUNC_TS_DUMMY, &indexTS, TSDB_DATA_TYPE_TIMESTAMP,
-                                         TSDB_KEYSIZE, getNewResColId(pCmd), TSDB_KEYSIZE, false);
+                                         TSDB_KEYSIZE, 0, TSDB_KEYSIZE, false);
         tstrncpy(pExpr->base.aliasName, aAggs[TSDB_FUNC_TS_DUMMY].name, sizeof(pExpr->base.aliasName));
 
         SColumnList ids = createColumnList(1, 0, 0);
@@ -3129,7 +3129,7 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
         // set the first column ts for top/bottom query
         int32_t tsFuncId = (functionId == TSDB_FUNC_MAVG) ? TSDB_FUNC_TS_DUMMY : TSDB_FUNC_TS;
         SColumnIndex index1 = {index.tableIndex, PRIMARYKEY_TIMESTAMP_COL_INDEX};
-        pExpr = tscExprAppend(pQueryInfo, tsFuncId, &index1, TSDB_DATA_TYPE_TIMESTAMP, TSDB_KEYSIZE, getNewResColId(pCmd),
+        pExpr = tscExprAppend(pQueryInfo, tsFuncId, &index1, TSDB_DATA_TYPE_TIMESTAMP, TSDB_KEYSIZE, 0,
                               0, false);
         tstrncpy(pExpr->base.aliasName, aAggs[tsFuncId].name, sizeof(pExpr->base.aliasName));
 
@@ -3155,7 +3155,7 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
         // todo REFACTOR
         // set the first column ts for top/bottom query
         SColumnIndex index1 = {index.tableIndex, PRIMARYKEY_TIMESTAMP_COL_INDEX};
-        pExpr = tscExprAppend(pQueryInfo, TSDB_FUNC_TS, &index1, TSDB_DATA_TYPE_TIMESTAMP, TSDB_KEYSIZE, getNewResColId(pCmd),
+        pExpr = tscExprAppend(pQueryInfo, TSDB_FUNC_TS, &index1, TSDB_DATA_TYPE_TIMESTAMP, TSDB_KEYSIZE, 0,
                                  0, false);
         tstrncpy(pExpr->base.aliasName, aAggs[TSDB_FUNC_TS].name, sizeof(pExpr->base.aliasName));
 

src/client/src/tscServer.c

@@ -837,7 +837,7 @@ static int32_t serializeSqlExpr(SSqlExpr* pExpr, STableMetaInfo* pTableMetaInfo,
     return TSDB_CODE_TSC_INVALID_OPERATION;
   }
 
-  if (pExpr->resColId >= 0) {
+  if (pExpr->resColId > 0) {
     tscError("result column id underflowed: %d", pExpr->resColId);
     return TSDB_CODE_TSC_RES_TOO_MANY;
   }