[TD-1478]<test> add test case query groupby with interval

tests/pytest/fulltest.sh

@@ -186,6 +186,7 @@ python3 ./test.py -f functions/function_sum.py
 python3 ./test.py -f functions/function_top.py
 #python3 ./test.py -f functions/function_twa.py
 python3 queryCount.py
+python3 ./test.py -f query/queryGroupbyWithInterval.py
 
 # tools
 python3 test.py -f tools/taosdemo.py

tests/pytest/query/queryGroupbyWithInterval.py

@@ -0,0 +1,53 @@
+###################################################################
+#           Copyright (c) 2016 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
+import taos
+from util.log import tdLog
+from util.cases import tdCases
+from util.sql import tdSql
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor(), logSql)
+
+    def run(self):
+        tdSql.prepare()
+        
+        tdSql.execute(
+            "create table stest(ts timestamp,size INT,filenum INT) tags (appname binary(500),tenant binary(500))")
+        tdSql.execute(
+            "insert into test1 using stest tags('test1','aaa') values ('2020-09-04 16:53:54.003',210,3)")
+        tdSql.execute(
+            "insert into test2 using stest tags('test1','aaa') values ('2020-09-04 16:53:56.003',210,3)")
+        tdSql.execute(
+            "insert into test11 using stest tags('test11','bbb') values ('2020-09-04 16:53:57.003',210,3)")
+        tdSql.execute(
+            "insert into test12 using stest tags('test11','bbb') values ('2020-09-04 16:53:58.003',210,3)")
+        tdSql.execute(
+            "insert into test21 using stest tags('test21','ccc') values ('2020-09-04 16:53:59.003',210,3)")
+        tdSql.execute(
+            "insert into test22 using stest tags('test21','ccc') values ('2020-09-04 16:54:54.003',210,3)")
+
+        tdSql.query("select sum(size) from stest interval(1d) group by appname")        
+        tdSql.checkRows(3)
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())