update

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

@@ -436,16 +436,16 @@ class TDTestCase:
             )
 
         tdSql.execute(
-                f"insert into {dbname}.sub1_bound values ( now(), -2147483643, -9223372036854775803, -32763, -123, -3.39E+38, -1.69e+308, True, 'binary_tb1', 'nchar_tb1', now() )"
+                f"insert into {dbname}.sub1_bound values ( now()+1s, -2147483643, -9223372036854775803, -32763, -123, -3.39E+38, -1.69e+308, True, 'binary_tb1', 'nchar_tb1', now() )"
             )
 
         tdSql.error(
                 f"insert into {dbname}.sub1_bound values ( now()+1s, 2147483648, 9223372036854775808, 32768, 128, 3.40E+38, 1.7e+308, True, 'binary_tb1', 'nchar_tb1', now() )"
             )
 
-        tdSql.query(f"select tail(c2,2) from {dbname}.sub1_bound order by 1 desc")
-        tdSql.checkRows(2)
-        tdSql.checkData(0,0,9223372036854775803)
+        tdSql.query(f"select tail(c2,1) from {dbname}.sub1_bound order by 1 desc")
+        tdSql.checkRows(1)
+        tdSql.checkData(0,0,-9223372036854775803)
 
     def run(self):  # sourcery skip: extract-duplicate-method, remove-redundant-fstring
         tdSql.prepare()