Question

我有这样的查询：

select from_tz(to_timestamp(v_time,'YY-MM-DD HH24:MI:SS'), 'UTC') 
      at time zone 'America/New_York' from dual;

如果我使用字符串Date而不是v_time，那么它可以正常工作。但是我需要在to_timestamp中传递变量v_time，我该怎么做？

提前致谢。

完整的代码在这里：

DECLARE
     v_test varchar2(200);
     v_cur_time varchar2(200);
     v_local_strem_time varchar2(200);
     v_time varchar2(200);
     v_time_diff NUMBER(20);
      v_temp varchar2(200);
     BEGIN

    SELECT TO_CHAR(SYSDATE, 'DD-MON-YY HH24:MI:SS') into v_cur_time
    FROM DUAL;

    select substr(((select TO_CHAR(date_time,'YY-MM-DD HH24:MI:SS') from observation_measurement where observation_measurement_id=5777992)), 1,17)
    into v_time  from dual;

    v_temp := v_time;
    select from_tz(to_timestamp(v_temp,'YY-MM-DD HH24:MI:SS'), 'UTC') 
    at time zone 'America/New_York' into v_local_strem_time from dual;

      select 24 * (to_date(v_cur_time, 'YY-MM-DD HH24:MI:SS') 
             - to_date(v_local_strem_time, 'YY-MM-DD HH24:MI:SS')) into v_time_diff 
       from dual;

       DBMS_OUTPUT.PUT_LINE(v_time_diff); 
    END;

Answer 1

变量必须为declared（code block或procedure或function或等等）

declare 
v_time varchar(20);
outval timestamp;
begin
v_time := '15-02-20 07:13:10';
select from_tz(to_timestamp(v_time,'YY-MM-DD HH24:MI:SS'), 'UTC') 
      at time zone 'America/New_York' into outval from dual;
dbms_output.put_line(outval);
end;

输出 20-FEB-15 02.13.10.000000 AM

编辑问题后编辑： 问题是v_local_strem_time包含AMERICA/NEW_YORK字符串，一种方法是使用SUBSTR函数删除不必要的字符串。让我来测试一下：

Create table observation_measurement(
observation_measurement_id number,
date_time date
)

insert into observation_measurement
values (5777992,to_date('214/10/09', 'YY-MM-DD HH24:MI:SS'));

DECLARE
     v_test varchar2(200);
     v_cur_time varchar2(200);
     v_local_strem_time varchar2(200);
     v_time varchar2(200);
     v_time_diff NUMBER(20);
     v_temp varchar2(200);
     BEGIN

    SELECT TO_CHAR(SYSDATE, 'DD-MON-YY HH24:MI:SS') into v_cur_time
    FROM DUAL;

    select substr(((select TO_CHAR(date_time,'YY-MM-DD HH24:MI:SS') from observation_measurement where observation_measurement_id=5777992)), 1,17)
    into v_time  from dual;

    v_temp := v_time;
    select from_tz(to_timestamp(v_temp,'YY-MM-DD HH24:MI:SS'), 'UTC') 
    at time zone 'America/New_York' into v_local_strem_time from dual;

      select 24 * (to_date(v_cur_time, 'YY-MM-DD HH24:MI:SS') 
             - to_date(substr(v_local_strem_time,0,18), 'YY-MM-DD HH24:MI:SS')) into v_time_diff 
       from dual;

       DBMS_OUTPUT.PUT_LINE(v_time_diff); 
    END;

输出： 143241

也许结构的observation_measurement.date_time数据类型不是日期，那时你可能需要进行适当的转换。

如何在oracle中的to_timestamp（）内传递字符串变量

1 个答案: