diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index e671c931590c8cfda84abb6a8fab6cdd3a4db0e5..0d5eef2eb458ab12f162a7aa8ebc078bf7c7d8b3 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -2674,6 +2674,7 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
   const char* msg15 = "parameter is out of range [1, 1000]";
   const char* msg16 = "elapsed duration should be greater than or equal to database precision";
   const char* msg17 = "elapsed/twa should not be used in nested query if inner query has group by clause";
+  const char* msg18 = "the second parameter is not an integer";
 
   switch (functionId) {
     case TSDB_FUNC_COUNT: {
@@ -3156,6 +3157,11 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
           return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg2);
         }
 
+        char* endptr = NULL;
+        strtoll(pParamElem[1].pNode->exprToken.z, &endptr, 10);
+        if ((endptr-pParamElem[1].pNode->exprToken.z != pParamElem[1].pNode->exprToken.n) || errno == ERANGE) {
+          return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg18);
+        }
         tVariantDump(pVariant, val, TSDB_DATA_TYPE_BIGINT, true);
 
         int64_t numRowsSelected = GET_INT64_VAL(val);
diff --git a/src/client/src/tscStream.c b/src/client/src/tscStream.c
index 73fdb02855e0bb0561630f87a2322385839698b1..2fa885ba7760a01e88eaecc114e1aced4cb11ea6 100644
--- a/src/client/src/tscStream.c
+++ b/src/client/src/tscStream.c
@@ -211,6 +211,7 @@ static void tscProcessStreamQueryCallback(void *param, TAOS_RES *tres, int numOf
     tfree(pSql->pSubs);
     pSql->subState.numOfSub = 0;
 
+    pSql->parseRetry = 0;
     int32_t code = tsParseSql(pSql, true);
     if (code == TSDB_CODE_SUCCESS) {
       cbParseSql(pStream, pSql, code);
@@ -220,6 +221,7 @@ static void tscProcessStreamQueryCallback(void *param, TAOS_RES *tres, int numOf
       tscError("0x%"PRIx64" open stream failed, code:%s", pSql->self, tstrerror(code));
       taosReleaseRef(tscObjRef, pSql->self);
       free(pStream);
+      return;
     }
 
 //    tscSetRetryTimer(pStream, pStream->pSql, retryDelay);
diff --git a/src/query/src/qAggMain.c b/src/query/src/qAggMain.c
index 9e80a4fb62d5e20bc0771714a2dfb82f66dae8d9..b6bf474a65f6a650087651c6571a7e9fbfa89d26 100644
--- a/src/query/src/qAggMain.c
+++ b/src/query/src/qAggMain.c
@@ -4618,9 +4618,7 @@ static void mavg_function(SQLFunctionCtx *pCtx) {
     }
   }
 
-  if (notNullElems <= 0) {
-    assert(pCtx->hasNull);
-  } else {
+ {
     for (int t = 0; t < pCtx->tagInfo.numOfTagCols; ++t) {
       SQLFunctionCtx* tagCtx = pCtx->tagInfo.pTagCtxList[t];
       if (tagCtx->functionId == TSDB_FUNC_TAG_DUMMY) {
diff --git a/tests/develop-test/2-query/function_mavg.py b/tests/develop-test/2-query/function_mavg.py
new file mode 100644
index 0000000000000000000000000000000000000000..fcc26b254614c5739d387dad2918083fbe8bde66
--- /dev/null
+++ b/tests/develop-test/2-query/function_mavg.py
@@ -0,0 +1,55 @@
+
+###################################################################
+#           Copyright (c) 2021 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+import sys
+from util.log import *
+from util.cases import *
+from util.sql import *
+
+
+class TDTestCase:
+    def caseDescription(self):
+        '''
+        case1<shenglian zhou>: [TD-10799]mavg(col, 4-3 ) promots error 
+        ''' 
+        return
+    
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+        self._conn = conn
+
+    def run(self):
+        print("running {}".format(__file__))
+        tdSql.execute("drop database if exists td10799")
+        tdSql.execute("create database if not exists td10799")
+        tdSql.execute('use td10799')
+
+        tdSql.execute('create stable st(ts timestamp , value int ) tags (ind int)') 
+        tdSql.execute('insert into tb1 using st tags(1) values(now ,1)') 
+        tdSql.execute('insert into tb1 using st tags(1) values(now+1s ,2)') 
+        tdSql.execute('insert into tb1 using st tags(1) values(now+2s ,3)') 
+        tdSql.query('select * from st')
+        tdSql.checkRows(3)
+        tdSql.query('select mavg(value, 100) from st group by tbname')
+        tdSql.checkRows(0)
+        tdSql.error('select mavg(value, 4-3) from st group by tbname')
+        tdSql.execute('drop database td10799')
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())
diff --git a/tests/develop-test/fulltest-query.sh b/tests/develop-test/fulltest-query.sh
index 77560893d75ed6f5191da6917536be2ff0ab9743..af669424ef5626e6429775a05f992d278967d678 100755
--- a/tests/develop-test/fulltest-query.sh
+++ b/tests/develop-test/fulltest-query.sh
@@ -3,4 +3,5 @@ python3 ./test.py -f 2-query/union-order.py
 python3 ./test.py -f 2-query/session_two_stage.py
 python3 ./test.py -f 2-query/timeline_agg_func_groupby.py
 python3 ./test.py -f 2-query/ts_2016.py
-python3 ./test.py -f 2-query/escape.py
\ No newline at end of file
+python3 ./test.py -f 2-query/function_mavg.py
+python3 ./test.py -f 2-query/escape.py