diff --git a/tests/develop-test/2-query/ts_hidden_column.py b/tests/develop-test/2-query/ts_hidden_column.py
new file mode 100644
index 0000000000000000000000000000000000000000..2e882bb892271037afeb91250f49b359e115ab4e
--- /dev/null
+++ b/tests/develop-test/2-query/ts_hidden_column.py
@@ -0,0 +1,59 @@
+###################################################################
+#           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-12145]function/clause program inserted column will be use as ts in outerquery        
+        case2<shenglian zhou>: [TD-12164]elapsed function can only take primary timestamp as first parameter
+        case3<shenglian zhou>: [TD-12165]_c0 can not be alias name
+        ''' 
+        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 td12145")
+        tdSql.execute("create database if not exists td12145")
+        tdSql.execute('use td12145')
+
+        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.error('select elapsed(ts00 ,1s) from (select elapsed(ts,1s) ts00 from tb1)')
+        tdSql.error('select elapsed(ts00 ,1s) from (select value ts00 from tb1)')
+        tdSql.error('select _c0 from (select value as _c0 , _c0 from st)')
+        tdSql.error('select ts from (select value as _c0 , ts from st)')
+        tdSql.query('select ts, max(nestvalue) from (select csum(value) nestvalue from tb1)')
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 1, 6)
+
+        tdSql.execute('drop database td12145')
+    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/2-query/union-order.py b/tests/develop-test/2-query/union-order.py
new file mode 100644
index 0000000000000000000000000000000000000000..6c2f20c129d294601f89757d01710f5e080a1717
--- /dev/null
+++ b/tests/develop-test/2-query/union-order.py
@@ -0,0 +1,60 @@
+###################################################################
+#           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-12229]fix union all query produces different result when switch query
+        ''' 
+        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 td12229")
+        tdSql.execute("create database if not exists td12229")
+        tdSql.execute('use td12229')
+
+        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.execute('create stable ste(ts timestamp , value int ) tags (ind int)') 
+        tdSql.query('select * from st')
+        tdSql.checkRows(3)
+        tdSql.query('select * from st union all select * from ste')
+        tdSql.checkRows(3)
+        tdSql.query('select * from ste union all select * from st')
+        tdSql.checkRows(3)
+        tdSql.query('select elapsed(ts) from ste group by tbname union all select elapsed(ts) from st group by tbname;')
+        tdSql.checkRows(1)
+        tdSql.query('select elapsed(ts) from st group by tbname union all select elapsed(ts) from ste group by tbname;')
+        tdSql.checkRows(1)
+        tdSql.execute('drop database td12229')
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())