在 oracle 中将时间字符串时区解析为时间戳的问题答案

【问题标题】：Issue with parsing time string timezone to timestamp in oracle在 oracle 中将时间字符串时区解析为时间戳的问题
【发布时间】：2019-06-28 10:28:40
【问题描述】：

我有一个日期字符串，如Mon Jun 24 23:42:36 EDT 2019，我想在我的 oracle sql 查询中从中获取时间戳。为此，我正在尝试以下查询

select TO_TIMESTAMP_TZ ('Mon Jun 24 23:42:36 EDT 2019', 'Dy Mon DD HH24:MI:SS TZR YYYY')  as "Creation Time"
from dual;

这给了我“未找到时区”的错误。我也尝试使用 TZD 进行时区解析，但它没有帮助。

将给定字符串解析为时间戳的正确日期格式是什么？

【问题讨论】：

标签： oracle timestamp

【解决方案1】：

时区EDT 不是有效时区。使用此查询检查有效的时区名称：

SELECT tzname, tzabbrev, TZ_OFFSET(tzname)
FROM V$TIMEZONE_NAMES 
WHERE tzabbrev = 'EDT' OR tzname = 'EDT';


+-------------------------------------------------------+
|TZNAME                      |TZABBREV|TZ_OFFSET(TZNAME)|
+-------------------------------------------------------+
|America/Detroit             |EDT     |-04:00           |
|America/Fort_Wayne          |EDT     |-04:00           |
|America/Grand_Turk          |EDT     |-04:00           |
|America/Indiana/Indianapolis|EDT     |-04:00           |
|America/Indiana/Marengo     |EDT     |-04:00           |
|America/Indiana/Petersburg  |EDT     |-04:00           |
|America/Indiana/Vevay       |EDT     |-04:00           |
|America/Indiana/Vincennes   |EDT     |-04:00           |
|America/Indiana/Winamac     |EDT     |-04:00           |
|America/Indianapolis        |EDT     |-04:00           |
|America/Iqaluit             |EDT     |-04:00           |
|America/Kentucky/Louisville |EDT     |-04:00           |
|America/Kentucky/Monticello |EDT     |-04:00           |
|America/Louisville          |EDT     |-04:00           |
|America/Montreal            |EDT     |-04:00           |
|America/Nassau              |EDT     |-04:00           |
|America/New_York            |EDT     |-04:00           |
|America/Nipigon             |EDT     |-04:00           |
|America/Pangnirtung         |EDT     |-04:00           |
|America/Santo_Domingo       |EDT     |-04:00           |
|America/Thunder_Bay         |EDT     |-04:00           |
|America/Toronto             |EDT     |-04:00           |
|Canada/Eastern              |EDT     |-04:00           |
|EST5EDT                     |EDT     |-04:00           |
|US/East-Indiana             |EDT     |-04:00           |
|US/Eastern                  |EDT     |-04:00           |
|US/Michigan                 |EDT     |-04:00           |
|America/Cancun              |EDT     |-05:00           |
|America/Indiana/Tell_City   |EDT     |-05:00           |
|America/Jamaica             |EDT     |-05:00           |
|America/Port-au-Prince      |EDT     |-05:00           |
|Jamaica                     |EDT     |-05:00           |
+-------------------------------------------------------+

例如这个正在工作：

select 
   TO_TIMESTAMP_TZ ('Mon Jun 24 23:42:36 America/New_York 2019', 'Dy Mon DD HH24:MI:SS TZR YYYY')  as "Creation Time"
from dual;

TZD 格式用于确定夏令时，例如2019-11-03 01:40:00 不明确，请参阅

ALTER SESSION SET ERROR_ON_OVERLAP_TIME = TRUE; -- default is FALSE

SELECT 
   TO_TIMESTAMP_TZ ('Sun Nov 03 01:42:36 America/New_York 2019', 'Dy Mon DD HH24:MI:SS TZR YYYY')  AS "Creation Time"
FROM dual;

Error at line 2
ORA-01883: overlap was disabled during a region transition


SELECT 
   TO_TIMESTAMP_TZ ('Sun Nov 03 01:42:36 America/New_York EST 2019', 'Dy Mon DD HH24:MI:SS TZR TZD YYYY')  AS "Creation Time A",
   TO_TIMESTAMP_TZ ('Sun Nov 03 01:42:36 America/New_York EDT 2019', 'Dy Mon DD HH24:MI:SS TZR TZD YYYY')  AS "Creation Time B"
FROM dual;

+-------------------------------------------------------------------------+
|Creation Time A                     |Creation Time B                     |
+-------------------------------------------------------------------------+
|03.11.2019 01:42:36.000000000 -05:00|03.11.2019 01:42:36.000000000 -04:00|
+-------------------------------------------------------------------------+

【讨论】：

不，EDT 是模棱两可的。您可以使用一些例外情况，请查看SELECT tzname, tzabbrev FROM V$TIMEZONE_NAMES WHERE tzname = tzabbrev;