[TD-2671]<test>: add test case for STABLE

tests/pytest/query/query.py

@@ -121,6 +121,7 @@ class TDTestCase:
 
         tdSql.query("select * from tb0")
         tdSql.checkRows(1)
+        
 
     def stop(self):
         tdSql.close()

tests/pytest/stable/insert.py

@@ -47,6 +47,40 @@ class TDTestCase:
         tdSql.query("select * from db.st where dev='dev_02'")
         tdSql.checkRows(1)
 
+        #For: https://jira.taosdata.com:18080/browse/TD-2671
+        print("==============step3")
+        tdSql.execute(
+            "create stable if not exists stb (ts timestamp, tagtype int) tags(dev nchar(50))")
+        tdSql.execute(
+            'CREATE TABLE if not exists dev_01 using stb tags("dev_01")')
+        tdSql.execute(
+            'CREATE TABLE if not exists dev_02 using stb tags("dev_02")')
+
+        print("==============step4")
+
+        tdSql.execute(
+            """INSERT INTO dev_01(ts, tagtype) VALUES('2020-05-13 10:00:00.000', 1),
+            ('2020-05-13 10:00:00.001', 1)
+             dev_02 VALUES('2020-05-13 10:00:00.001', 1)""")
+
+        tdSql.query("select * from db.stb where dev='dev_01'")
+        tdSql.checkRows(2)
+
+        tdSql.query("select * from db.stb where dev='dev_02'")
+        tdSql.checkRows(1)
+
+        tdSql.query("describe db.stb")
+        tdSql.checkRows(3)
+
+        tdSql.execute("alter stable db.stb add tag t1 int")
+        tdSql.query("describe db.stb")
+        tdSql.checkRows(4)
+
+        tdSql.execute("drop stable db.stb")
+        tdSql.query("show stables")
+        tdSql.checkRows(1)
+
+
     def stop(self):
         tdSql.close()
         tdLog.success("%s successfully executed" % __file__)