Sql Oracle数据库中DST更改的时间似乎是凌晨1点，而不是凌晨2点_Sql_Oracle

Sql Oracle数据库中DST更改的时间似乎是凌晨1点，而不是凌晨2点

sql oracle

Sql Oracle数据库中DST更改的时间似乎是凌晨1点，而不是凌晨2点,sql,oracle,Sql,Oracle,我试图在Oracle中将UTC时间转换为BST时间-但是，Oracle中的数据更改时间似乎是凌晨1点而不是凌晨2点。或者我在这里错过了什么？我使用以下代码来说明和测试该问题： WITH time1 AS (select cast('2020-03-29 01:00:00 UTC' ASTIMESTAMP WITH TIME ZONE) AS UTC_time FROM dual) SELECT UTC_time, (UTC_time AT TIME ZONE 'Europe/London') A

我试图在Oracle中将UTC时间转换为BST时间-但是，Oracle中的数据更改时间似乎是凌晨1点而不是凌晨2点。或者我在这里错过了什么？我使用以下代码来说明和测试该问题：

WITH time1 AS (select cast('2020-03-29 01:00:00 UTC' ASTIMESTAMP WITH TIME ZONE) AS UTC_time FROM dual)
SELECT UTC_time, (UTC_time AT TIME ZONE 'Europe/London') AS bst FROM time1

在协调世界时1:00:00，英国夏令时时间是2:00:00-应该是1:00:00，Oracle是对的，您的期望似乎是错误的。您可以看到欧洲/伦敦DST的变化

在欧洲/伦敦有以下内容：

# See EU for rules starting in 1996.
...
# Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
Zone    Europe/London   -0:01:15 -      LMT     1847 Dec  1  0:00s
                         0:00   GB-Eire %s      1968 Oct 27
                         1:00   -       BST     1971 Oct 31  2:00u
                         0:00   GB-Eire %s      1996
                         0:00   EU      GMT/BST

因此，自1996年以来，英国一直遵循欧盟规则，即：

# Europe

# The following rules are for the European Union and for its
# predecessor organization, the European Communities.
# For brevity they are called "EU rules" elsewhere in this file.

# Rule  NAME    FROM    TO      TYPE    IN      ON      AT      SAVE    LETTER/S
Rule    EU      1977    1980    -       Apr     Sun>=1   1:00u  1:00    S
Rule    EU      1977    only    -       Sep     lastSun  1:00u  0       -
Rule    EU      1978    only    -       Oct      1       1:00u  0       -
Rule    EU      1979    1995    -       Sep     lastSun  1:00u  0       -
Rule    EU      1981    max     -       Mar     lastSun  1:00u  1:00    S
Rule    EU      1996    max     -       Oct     lastSun  1:00u  0       -

所以。。。在英国（以及欧盟其他国家），DST从3月的最后一个星期日起在协调世界时01:00应用，明年是2020-03-29协调世界时01:00:00。它将在DST上持续到10月的最后一个星期日协调世界时01:00，即明年的协调世界时2020-10-25 01:00:00

Oracle遵循这些规则：

with time1 (utc_time) as (
            select timestamp '2020-03-29 00:00:00.000 UTC' FROM dual
  union all select timestamp '2020-03-29 00:59:59.999 UTC' FROM dual
  union all select timestamp '2020-03-29 01:00:00.000 UTC' FROM dual
  union all select timestamp '2020-03-29 01:59:59.999 UTC' FROM dual
  union all select timestamp '2020-03-29 02:00:00.000 UTC' FROM dual
  --
  union all select timestamp '2020-10-25 00:00:00.000 UTC' FROM dual
  union all select timestamp '2020-10-25 00:59:59.999 UTC' FROM dual
  union all select timestamp '2020-10-25 01:00:00.000 UTC' FROM dual
  union all select timestamp '2020-10-25 01:59:59.999 UTC' FROM dual
  union all select timestamp '2020-10-25 02:00:00.000 UTC' FROM dual
)
select utc_time,
  utc_time at time zone 'Europe/London' as london_time,
  to_char(utc_time at time zone 'Europe/London', 'TZD') as "DST?"
from time1
order by utc_time;

UTC_TIME                          LONDON_TIME                                 DST?  
--------------------------------- ------------------------------------------- ------
2020-03-29 00:00:00.000000000 UTC 2020-03-29 00:00:00.000000000 EUROPE/LONDON GMT   
2020-03-29 00:59:59.999000000 UTC 2020-03-29 00:59:59.999000000 EUROPE/LONDON GMT   
2020-03-29 01:00:00.000000000 UTC 2020-03-29 02:00:00.000000000 EUROPE/LONDON BST   
2020-03-29 01:59:59.999000000 UTC 2020-03-29 02:59:59.999000000 EUROPE/LONDON BST   
2020-03-29 02:00:00.000000000 UTC 2020-03-29 03:00:00.000000000 EUROPE/LONDON BST   
2020-10-25 00:00:00.000000000 UTC 2020-10-25 01:00:00.000000000 EUROPE/LONDON BST   
2020-10-25 00:59:59.999000000 UTC 2020-10-25 01:59:59.999000000 EUROPE/LONDON BST   
2020-10-25 01:00:00.000000000 UTC 2020-10-25 01:00:00.000000000 EUROPE/LONDON GMT   
2020-10-25 01:59:59.999000000 UTC 2020-10-25 01:59:59.999000000 EUROPE/LONDON GMT   
2020-10-25 02:00:00.000000000 UTC 2020-10-25 02:00:00.000000000 EUROPE/LONDON GMT

在中欧，DST适用于同一UTC时间，但当地时间当然不同：

with time1 (utc_time) as (
  ...
)
select utc_time,
  utc_time at time zone 'Europe/Paris' as paris_time,
  to_char(utc_time at time zone 'Europe/Paris', 'TZD') as "DST?"
from time1
order by utc_time;

UTC_TIME                          PARIS_TIME                                 DST?  
--------------------------------- ------------------------------------------ ------
2020-03-29 00:00:00.000000000 UTC 2020-03-29 01:00:00.000000000 EUROPE/PARIS CET   
2020-03-29 00:59:59.999000000 UTC 2020-03-29 01:59:59.999000000 EUROPE/PARIS CET   
2020-03-29 01:00:00.000000000 UTC 2020-03-29 03:00:00.000000000 EUROPE/PARIS CEST  
2020-03-29 01:59:59.999000000 UTC 2020-03-29 03:59:59.999000000 EUROPE/PARIS CEST  
2020-03-29 02:00:00.000000000 UTC 2020-03-29 04:00:00.000000000 EUROPE/PARIS CEST  
2020-10-25 00:00:00.000000000 UTC 2020-10-25 02:00:00.000000000 EUROPE/PARIS CEST  
2020-10-25 00:59:59.999000000 UTC 2020-10-25 02:59:59.999000000 EUROPE/PARIS CEST  
2020-10-25 01:00:00.000000000 UTC 2020-10-25 02:00:00.000000000 EUROPE/PARIS CET   
2020-10-25 01:59:59.999000000 UTC 2020-10-25 02:59:59.999000000 EUROPE/PARIS CET   
2020-10-25 02:00:00.000000000 UTC 2020-10-25 03:00:00.000000000 EUROPE/PARIS CET

可能这就是为什么您希望在02:00之前不会看到时间变化，但如果是这样，您会混淆UTC和当地时间，和/或英国和中欧

与您的问题没有直接关系，但在我的CTE中，我已从使用字符串转换为使用timsetamp。除了打字稍微少一点外，格式也很明确。当您强制转换时，您依赖于会话的NLS设置，该设置与您提供的字符串格式相匹配，因此尽管强制转换适用于您，但可能不适用于运行您的代码的其他人。如果您不想（或不能）使用文字，那么使用带有显式格式掩码的

to_timestamp_tz（）

更安全。

Oracle是正确的，您的期望似乎是错误的。您可以看到欧洲/伦敦DST的变化

在欧洲/伦敦有以下内容：

# See EU for rules starting in 1996.
...
# Zone  NAME            GMTOFF  RULES   FORMAT  [UNTIL]
Zone    Europe/London   -0:01:15 -      LMT     1847 Dec  1  0:00s
                         0:00   GB-Eire %s      1968 Oct 27
                         1:00   -       BST     1971 Oct 31  2:00u
                         0:00   GB-Eire %s      1996
                         0:00   EU      GMT/BST

因此，自1996年以来，英国一直遵循欧盟规则，即：

# Europe

# The following rules are for the European Union and for its
# predecessor organization, the European Communities.
# For brevity they are called "EU rules" elsewhere in this file.

# Rule  NAME    FROM    TO      TYPE    IN      ON      AT      SAVE    LETTER/S
Rule    EU      1977    1980    -       Apr     Sun>=1   1:00u  1:00    S
Rule    EU      1977    only    -       Sep     lastSun  1:00u  0       -
Rule    EU      1978    only    -       Oct      1       1:00u  0       -
Rule    EU      1979    1995    -       Sep     lastSun  1:00u  0       -
Rule    EU      1981    max     -       Mar     lastSun  1:00u  1:00    S
Rule    EU      1996    max     -       Oct     lastSun  1:00u  0       -

Oracle遵循这些规则：

with time1 (utc_time) as (
            select timestamp '2020-03-29 00:00:00.000 UTC' FROM dual
  union all select timestamp '2020-03-29 00:59:59.999 UTC' FROM dual
  union all select timestamp '2020-03-29 01:00:00.000 UTC' FROM dual
  union all select timestamp '2020-03-29 01:59:59.999 UTC' FROM dual
  union all select timestamp '2020-03-29 02:00:00.000 UTC' FROM dual
  --
  union all select timestamp '2020-10-25 00:00:00.000 UTC' FROM dual
  union all select timestamp '2020-10-25 00:59:59.999 UTC' FROM dual
  union all select timestamp '2020-10-25 01:00:00.000 UTC' FROM dual
  union all select timestamp '2020-10-25 01:59:59.999 UTC' FROM dual
  union all select timestamp '2020-10-25 02:00:00.000 UTC' FROM dual
)
select utc_time,
  utc_time at time zone 'Europe/London' as london_time,
  to_char(utc_time at time zone 'Europe/London', 'TZD') as "DST?"
from time1
order by utc_time;

UTC_TIME                          LONDON_TIME                                 DST?  
--------------------------------- ------------------------------------------- ------
2020-03-29 00:00:00.000000000 UTC 2020-03-29 00:00:00.000000000 EUROPE/LONDON GMT   
2020-03-29 00:59:59.999000000 UTC 2020-03-29 00:59:59.999000000 EUROPE/LONDON GMT   
2020-03-29 01:00:00.000000000 UTC 2020-03-29 02:00:00.000000000 EUROPE/LONDON BST   
2020-03-29 01:59:59.999000000 UTC 2020-03-29 02:59:59.999000000 EUROPE/LONDON BST   
2020-03-29 02:00:00.000000000 UTC 2020-03-29 03:00:00.000000000 EUROPE/LONDON BST   
2020-10-25 00:00:00.000000000 UTC 2020-10-25 01:00:00.000000000 EUROPE/LONDON BST   
2020-10-25 00:59:59.999000000 UTC 2020-10-25 01:59:59.999000000 EUROPE/LONDON BST   
2020-10-25 01:00:00.000000000 UTC 2020-10-25 01:00:00.000000000 EUROPE/LONDON GMT   
2020-10-25 01:59:59.999000000 UTC 2020-10-25 01:59:59.999000000 EUROPE/LONDON GMT   
2020-10-25 02:00:00.000000000 UTC 2020-10-25 02:00:00.000000000 EUROPE/LONDON GMT

在中欧，DST适用于同一UTC时间，但当地时间当然不同：

with time1 (utc_time) as (
  ...
)
select utc_time,
  utc_time at time zone 'Europe/Paris' as paris_time,
  to_char(utc_time at time zone 'Europe/Paris', 'TZD') as "DST?"
from time1
order by utc_time;

UTC_TIME                          PARIS_TIME                                 DST?  
--------------------------------- ------------------------------------------ ------
2020-03-29 00:00:00.000000000 UTC 2020-03-29 01:00:00.000000000 EUROPE/PARIS CET   
2020-03-29 00:59:59.999000000 UTC 2020-03-29 01:59:59.999000000 EUROPE/PARIS CET   
2020-03-29 01:00:00.000000000 UTC 2020-03-29 03:00:00.000000000 EUROPE/PARIS CEST  
2020-03-29 01:59:59.999000000 UTC 2020-03-29 03:59:59.999000000 EUROPE/PARIS CEST  
2020-03-29 02:00:00.000000000 UTC 2020-03-29 04:00:00.000000000 EUROPE/PARIS CEST  
2020-10-25 00:00:00.000000000 UTC 2020-10-25 02:00:00.000000000 EUROPE/PARIS CEST  
2020-10-25 00:59:59.999000000 UTC 2020-10-25 02:59:59.999000000 EUROPE/PARIS CEST  
2020-10-25 01:00:00.000000000 UTC 2020-10-25 02:00:00.000000000 EUROPE/PARIS CET   
2020-10-25 01:59:59.999000000 UTC 2020-10-25 02:59:59.999000000 EUROPE/PARIS CET   
2020-10-25 02:00:00.000000000 UTC 2020-10-25 03:00:00.000000000 EUROPE/PARIS CET

可能这就是为什么您希望在02:00之前不会看到时间变化，但如果是这样，您会混淆UTC和当地时间，和/或英国和中欧

to_timestamp_tz（）

更安全。

为什么您认为这是错误的。DST时间在凌晨2:00生效，而不是1:00生效。不，不生效。无论如何，格林尼治标准时间/英国夏令时。其他地区有不同的规则和不同的当地时间；GMT/BST的变化与CET/CEST发生在同一UTC时间（我相信是设计上的变化），所以在巴黎说变化发生在CET时间02:00，这仍然是UTC时间01:00。尝试

时间戳'2020-03-29 01:00:00 UTC'

而不是演员阵容。你为什么认为这是错误的。DST时间在凌晨2:00生效，而不是1:00生效。不，不生效。无论如何，格林尼治标准时间/英国夏令时。其他地区有不同的规则和不同的当地时间；GMT/BST的变化与CET/CEST发生在同一UTC时间（我相信是故意的），所以在巴黎说变化发生在CET时间02:00，现在仍然是UTC时间01:00。尝试

时间戳“2020-03-29 01:00:00 UTC”

而不是演员阵容。感谢你的全面回答：）我确实错了Tanks的全面回答：）我确实错了