SQLDeveloper返回与SQLPlus命令行不同的日期

我在SQL Developer中具有以下脚本，但是在SQL Plus命令行中运行它似乎返回无效的日期。

set serveroutput on;
DECLARE
   yesterday varchar2(30);
   tz_yesterday varchar2(30);
BEGIN
   select sysdate - 1 into yesterday from dual;
   select cast(yesterday as timestamp WITH LOCAL TIME ZONE) into tz_yesterday from dual;
   dbms_output.put_line(yesterday);
   dbms_output.put_line(tz_yesterday);
END;

这是SQL Developer提供的输出，它是正确的：

10-OCT-18
10-OCT-18 12.00.00.000000 AM

这就是我在SQL Plus中得到的

SQL> l
  1  DECLARE
  2    g_vendor_id NUMBER;
  3    g_product_id NUMBER;
  4    yesterday varchar2(30);
  5    tz_yesterday varchar2(30);
  6    g_user_id NUMBER;
  7   BEGIN
  8    select sysdate - 1 into yesterday from dual;
  9    select cast(yesterday as timestamp WITH LOCAL TIME ZONE) into tz_yesterday from dual;
 10  dbms_output.put_line(yesterday);
 11  dbms_output.put_line(tz_yesterday);
 12* End;
SQL> /
DECLARE
*
ERROR at line 1:
ORA-01843: not a valid month
ORA-06512: at line 9

有人可以在这里解释差异吗？

不要将日期或时间戳记值存储在varchar变量中，请始终使用正确的数据类型：

set serveroutput on;
DECLARE
   yesterday date;
   tz_yesterday timestamp with local time zone;
BEGIN
   yesterday := sysdate - 1;
   tz_yesterday := cast(yesterday as timestamp WITH LOCAL TIME ZONE);
   dbms_output.put_line(yesterday);
   dbms_output.put_line(tz_yesterday);
END;
/