>我在表 A 中有一列作为
select create_time from table_a;
值为
08-MAR-19 08.23.47.897000000 PM GMT.
出于某些业务目的,此列已标记为VARCHAR2。现在我正在尝试获取此列并将值转换为 TIMESTAMP 出于某种目的,如下所示:
SELECT TO_TIMESTAMP(create_time, 'DD-MON-YYYY HH.MI.SS.FF AM') from table_a;
但是我收到错误:
ORA-01830: date format picture ends before converting entire input string
有人可以帮助我将此 varchar 数据转换为时间戳。我尝试这样做的原因是,我需要将这个时间从一个时区转换为另一个时区: 例如:
SELECT FROM_TZ(TO_TIMESTAMP(create_time, 'DD-MON-YYYY HH.MI.SS.FF AM'), 'UTC') AT TIME ZONE 'CET' from table_a;
SQL> select replace('08-MAR-19 08.23.47.897000000 PM GMT','GMT','') AS RESULT from dual
;
RESULT
--------------------------------
08-MAR-19 08.23.47.897000000 PM
SQL> select to_timestamp(replace('08-MAR-19 08.23.47.897000000 PM GMT','GMT','')) as RESULT from dual ;
RESULT
---------------------------------------------------------------------------
08-MAR-19 08.23.47.897000000 PM
SQL> select from_tz(to_timestamp(replace('08-MAR-19 08.23.47.897000000 PM GMT','GMT','')),'UTC') AT TIME ZONE 'CET' AS RESULT from dual ;
RESULT
---------------------------------------------------------------------------
08-MAR-19 09.23.47.897000000 PM CET
SQL>
格式字符串中不考虑末尾GMT
的四个字符
SELECT TO_TIMESTAMP('08-MAR-19 08.23.47.897000000 PM GMT', 'DD-MON-YYYY HH.MI.SS.FF AM') from dual;
以下处理:
SELECT TO_TIMESTAMP(substr(create_time, 1, LENGTH(create_time) -4), 'DD-MON-YYYY HH.MI.SS.FF AM') t from dual;
试试这个。
select TO_TIMESTAMP( REPLACE(ts, 'GMT', '')) from test_timestamp;
使用REPLACE
删除GMT
WITH A AS (SELECT REPLACE('08-MAR-19 08.23.47.897000000 PM GMT','GMT','') AS D FROM DUAL)
SELECT TO_TIMESTAMP (D, 'DD-MON-YYYY HH.MI.SS.FF AM')
FROM A
执行以下操作:
to_timestamp(replace(create_time ,'GMT', null))
依赖于时间戳格式(尤其是具有 RR 年份掩码)和月份缩写语言的 NLS 设置。这样做会更安全:
to_timestamp(replace(create_time, ' GMT', null),
'DD-MON-RR HH.MI.SS.FF AM', 'NLS_DATE_LANGUAGE=ENGLISH')
如果时区并不总是 GMT,但始终是有效且可识别的区域(例如,不是 BST),那么您可能需要保留包括该区域在内的完整日期/时间:
to_timestamp_tz(create_time, 'DD-MON-RR HH.MI.SS.FF AM TZR',
'NLS_DATE_LANGUAGE=ENGLISH')
如果您希望将其作为纯时间戳,您可以强制转换它,可能先更改为特定区域:
cast(to_timestamp_tz(create_time, 'DD-MON-RR HH.MI.SS.FF AM TZR',
'NLS_DATE_LANGUAGE=ENGLISH') as timestamp)
或
cast(to_timestamp_tz(create_time, 'DD-MON-RR HH.MI.SS.FF AM TZR',
'NLS_DATE_LANGUAGE=ENGLISH') at time zone 'Asia/Tokyo' as timestamp)
或规范化为 UTC(当然,这不会影响 GMT 值,因为它们本质上是相同的):
sys_extract_utc(to_timestamp_tz(create_time, 'DD-MON-RR HH.MI.SS.FF AM TZR',
'NLS_DATE_LANGUAGE=ENGLISH'))
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