TD-1227 add test case

tests/pytest/fulltest.sh

@@ -145,6 +145,8 @@ python3 ./test.py -f query/queryJoin.py
 python3 ./test.py -f query/select_last_crash.py
 python3 ./test.py -f query/queryNullValueTest.py
 python3 ./test.py -f query/queryInsertValue.py
+python3 ./test.py -f query/queryConnection.py
+python3 ./test.py -f query/natualInterval.py
 
 #stream
 python3 ./test.py -f stream/metric_1.py

tests/pytest/query/queryConnection.py

@@ -0,0 +1,52 @@
+###################################################################
+#           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 if not exists st (ts timestamp, tagtype int) tags(dev nchar(50))")
+        tdSql.execute(
+            'CREATE TABLE if not exists dev_001 using st tags("dev_01")')
+        tdSql.execute(
+            'CREATE TABLE if not exists dev_002 using st tags("dev_02")')        
+
+        tdSql.execute(
+            """INSERT INTO dev_001(ts, tagtype) VALUES('2020-05-13 10:00:00.000', 1),
+            ('2020-05-13 10:00:00.001', 1)
+             dev_002 VALUES('2020-05-13 10:00:00.001', 1)""")
+
+        for i in range(10):
+            for j in range(1000):
+                tdSql.query("select * from db.st")      
+            tdLog.sleep(10)
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())