add test case

tests/pytest/functions/function_elapsed_case.py

@@ -223,8 +223,8 @@ class ElapsedCase:
         self.orderbyForStableCheck("select elapsed(ts) from st1 where ts > '2021-11-22 00:00:00' and ts < '2021-11-23 00:00:00' interval(1000m) group by tbname", 1, 2)
 
         #nested query
-        resAsc = tdSql.getResult("select elapsed(ts) from (select * from t1 where ts > '2021-11-22 00:00:00' and ts < '2021-11-23 00:00:00')")
-        resDesc = tdSql.getResult("select elapsed(ts) from (select * from t1 where ts > '2021-11-22 00:00:00' and ts < '2021-11-23 00:00:00' order by ts desc)")
+        resAsc = tdSql.getResult("select elapsed(ts) from (select csum(i) from t1 where ts > '2021-11-22 00:00:00' and ts < '2021-11-23 00:00:00')")
+        resDesc = tdSql.getResult("select elapsed(ts) from (select csum(i) from t1 where ts > '2021-11-22 00:00:00' and ts < '2021-11-23 00:00:00' order by ts desc)")
         resRows = len(resAsc)
         for i in range(resRows):
             tdSql.checkEqual(resAsc[i][0], resDesc[resRows - i - 1][0])