diff --git a/tests/pytest/functions/all_null_value.py b/tests/pytest/functions/all_null_value.py
index 5354b48f80dae25f7cd65fb00f90e4eeef2908cc..64791831107de4720ea43f26c250ebfb3da7195d 100644
--- a/tests/pytest/functions/all_null_value.py
+++ b/tests/pytest/functions/all_null_value.py
@@ -73,8 +73,8 @@ class TDTestCase:
         tdSql.query("select spread(c1) from st")
         tdSql.checkRows(0)
 
-        # tdSql.query("select stddev(c1) from st")
-        # tdSql.checkRows(0)
+        tdSql.query("select stddev(c1) from st")
+        tdSql.checkRows(0)
 
         tdSql.query("select sum(c1) from st")
         tdSql.checkRows(0)
diff --git a/tests/pytest/query/query.py b/tests/pytest/query/query.py
index 87635f86f39fb317907f689307eeefa9f3aef124..d0750ac4a5cbe631e38017e6c81746659ad16e49 100644
--- a/tests/pytest/query/query.py
+++ b/tests/pytest/query/query.py
@@ -44,6 +44,20 @@ class TDTestCase:
         tdSql.query("select * from db.st where ts='2020-05-13 10:00:00.000'")
         tdSql.checkRows(1)
 
+        tdSql.query("select tbname, dev from dev_001") 
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 'dev_001')
+        tdSql.checkData(0, 1, 'dev_01')
+
+        tdSql.query("select tbname, dev, tagtype from dev_001") 
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 0, 'dev_001')
+        tdSql.checkData(0, 1, 'dev_01')
+        tdSql.checkData(0, 2, 1)
+        tdSql.checkData(1, 0, 'dev_001')
+        tdSql.checkData(1, 1, 'dev_01')
+        tdSql.checkData(1, 2, 1)
+
         ## test case for https://jira.taosdata.com:18080/browse/TD-2488
         tdSql.execute("create table m1(ts timestamp, k int) tags(a int)")
         tdSql.execute("create table t1 using m1 tags(1)")
@@ -63,6 +77,8 @@ class TDTestCase:
         tdSql.checkRows(1)
         tdSql.checkData(0, 0, 1)
 
+
+
     def stop(self):
         tdSql.close()
         tdLog.success("%s successfully executed" % __file__)
diff --git a/tests/pytest/query/queryInterval.py b/tests/pytest/query/queryInterval.py
index 9cc468b34e6133af393d9d0d800e64d14e85c430..ce8d05ae50aa61646b20e07e9484d00559e92b49 100644
--- a/tests/pytest/query/queryInterval.py
+++ b/tests/pytest/query/queryInterval.py
@@ -100,7 +100,23 @@ class TDTestCase:
         tdSql.checkData(1, 1, None)
         tdSql.checkData(2, 1, None)
 
-        
+         # test case for https://jira.taosdata.com:18080/browse/TD-2659， https://jira.taosdata.com:18080/browse/TD-2660
+        tdSql.execute("create database test3")
+        tdSql.execute("use test3")
+        tdSql.execute("create table tb(ts timestamp, c int)")
+        tdSql.execute("insert into tb values('2020-10-30 18:11:56.680', -111)")
+        tdSql.execute("insert into tb values('2020-11-19 18:11:45.773', null)")
+        tdSql.execute("insert into tb values('2020-12-09 18:11:17.098', null)")
+        tdSql.execute("insert into tb values('2020-12-29 11:00:49.412', 1)")
+        tdSql.execute("insert into tb values('2020-12-29 11:00:50.412', 2)")
+        tdSql.execute("insert into tb values('2020-12-29 11:00:52.412', 3)")
+
+        tdSql.query("select first(ts),twa(c) from tb interval(14a)")
+        tdSql.checkRows(6)
+
+        tdSql.query("select twa(c) from tb group by c")
+        tdSql.checkRows(4)
+
 
     def stop(self):
         tdSql.close()
diff --git a/tests/pytest/stream/history.py b/tests/pytest/stream/history.py
index 890580001cf40a13ba18f6f81a3bd0faaac67991..cb8a4d598651473f907aa05a0609c9ce68c78f82 100644
--- a/tests/pytest/stream/history.py
+++ b/tests/pytest/stream/history.py
@@ -48,12 +48,16 @@ class TDTestCase:
         tdSql.execute("insert into car3 values('2019-01-01 00:00:01.389', 1)")
         tdSql.execute("insert into car4 values('2019-01-01 00:00:01.829', 1)")
 
+        tdSql.error("create table strm as select count(*) from cars")
+
         tdSql.execute("create table strm as select count(*) from cars interval(4s)")
         tdSql.waitedQuery("select * from strm", 2, 100)
         tdSql.checkData(0, 1, 11)
         tdSql.checkData(1, 1, 2)
 
 
+
+
     def stop(self):
         tdSql.close()
         tdLog.success("%s successfully executed" % __file__)
diff --git a/tests/pytest/tools/taosdemoTest.py b/tests/pytest/tools/taosdemoTest.py
index 1a976aef594576ba29b928465fc38baea6dcb63e..2a4a552c8fb87f9c5a3169afcad71793462b924f 100644
--- a/tests/pytest/tools/taosdemoTest.py
+++ b/tests/pytest/tools/taosdemoTest.py
@@ -49,7 +49,7 @@ class TDTestCase:
         else:
             tdLog.info("taosd found in %s" % buildPath)
         binPath = buildPath+ "/build/bin/"
-        os.system("yes | %staosdemo -t %d -n %d" % (binPath,self.numberOfTables, self.numberOfRecords))
+        os.system("yes | %staosdemo -t %d -n %d -x" % (binPath,self.numberOfTables, self.numberOfRecords))
 
         tdSql.execute("use test")
         tdSql.query("select count(*) from meters")
@@ -61,6 +61,8 @@ class TDTestCase:
         tdSql.query("select apercentile(f1, 1) from test.meters interval(10s)")
         tdSql.checkRows(11)
 
+        tdSql.error("select loc, count(loc) from test.meters")
+
     def stop(self):
         tdSql.close()
         tdLog.success("%s successfully executed" % __file__)