add test cases

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

@@ -95,9 +95,20 @@ class TDTestCase:
             self.data_check(f'{self.stbname}_{i}',self.values_list,'ctb')
         self.data_check(self.stbname,self.values_list,'stb',self.tbnum)
         tdSql.execute(f'drop database {self.dbname}')
+    def timestamp_change_return_type(self):
+        tdSql.query(f"select to_unixtimestamp('1970-01-01 08:00:00+08:00', 0);")
+        tdSql.checkEqual(tdSql.queryResult[0][0], 0)
+        tdSql.query(f"select to_unixtimestamp('1970-01-01 08:00:00+08:00', 1);")
+        tdSql.checkEqual(tdSql.queryResult[0][0], datetime.datetime(1970, 1, 1, 8, 0, 0))
+        tdSql.error(f"select to_unixtimestamp('1970-01-01 08:00:00+08:00', 2);")
+        tdSql.error(f"select to_unixtimestamp('1970-01-01 08:00:00+08:00', 1.5);")
+        tdSql.error(f"select to_unixtimestamp('1970-01-01 08:00:00+08:00', 'abc');")
+        tdSql.error(f"select to_unixtimestamp('1970-01-01 08:00:00+08:00', true);")
+        tdSql.error(f"select to_unixtimestamp('1970-01-01 08:00:00+08:00', 1, 3);")
     def run(self):  # sourcery skip: extract-duplicate-method
         self.timestamp_change_check_ntb()
         self.timestamp_change_check_stb()
+        self.timestamp_change_return_type()
     def stop(self):
         tdSql.close()
         tdLog.success(f"{__file__} successfully executed")