add test case

tests/system-test/2-query/systable_func.py

+import taos
+import sys
+
+from util.log import *
+from util.sql import *
+from util.cases import *
+
+
+
+class TDTestCase:
+
+    def init(self, conn, logSql, replicaVar=1):
+        self.replicaVar = int(replicaVar)
+        tdLog.debug(f"start to excute {__file__}")
+        #tdSql.init(conn.cursor())
+        tdSql.init(conn.cursor(), logSql)  # output sql.txt file
+
+    def run(self):
+        tdSql.prepare()
+
+        tdSql.query(f"select count(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select sum(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select min(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select max(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select stddev(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select avg(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select apercentile(`columns`, 50) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select top(`columns`, 3) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select bottom(`columns`, 3) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select spread(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select histogram(`columns`, 'user_input', '[1, 3, 5]', 0) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select hyperloglog(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select sample(`columns`, 3) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select tail(`columns`, 3) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select unique(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.query(f"select mode(`columns`) from `information_schema`.`ins_tables`;")
+
+        tdSql.error(f"select leastsquares(`columns`, 1, 1) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select elapsed(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select interp(`columns`) from `information_schema`.`ins_tables` range(0, 1) every(1s) fill(null);")
+        tdSql.error(f"select percentile(`columns`, 50) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select derivative(`columns`, 1s, 0) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select irate(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select last_row(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select last(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select first(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select twa(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select diff(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select statecount(`columns`, 'GE', 0) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select stateduration(`columns`, 'GE', 0, 1s) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select csum(`columns`) from `information_schema`.`ins_tables`;")
+        tdSql.error(f"select mavg(`columns`, 1) from `information_schema`.`ins_tables`;")
+
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success(f"{__file__} successfully executed")
+
+tdCases.addLinux(__file__, TDTestCase())
+tdCases.addWindows(__file__, TDTestCase())