Answers:
尝试：
CREATE FUNCTION dbo.fn_ConvertToDateTime (@Datetime BIGINT)
RETURNS DATETIME
AS
BEGIN
DECLARE @LocalTimeOffset BIGINT
,@AdjustedLocalDatetime BIGINT;
SET @LocalTimeOffset = DATEDIFF(second,GETDATE(),GETUTCDATE())
SET @AdjustedLocalDatetime = @Datetime - @LocalTimeOffset
RETURN (SELECT DATEADD(second,@AdjustedLocalDatetime, CAST('1970-01-01 00:00:00' AS datetime)))
END;
GO这对我有用：
Select
dateadd(S, [unixtime], '1970-01-01')
From [Table]万一有人想知道为什么是1970-01-01，这被称为大纪元时间。
以下是维基百科的引文：
自1970年1月1日（星期四）协调世界时（UTC）00:00:00起经过的秒数，[1] [注1]不计算leap秒。
如果有人遇到以下错误：
将表达式转换为数据类型int的算术溢出错误
由于unix时间戳在bigint（而不是int）中，因此可以使用以下命令：
SELECT DATEADD(S, CONVERT(int,LEFT(1462924862735870900, 10)), '1970-01-01')
FROM TABLE用unix-timestamp替换您实际列的硬编码时间戳
像这样
将Unix（纪元）日期时间添加到以秒为单位的基本日期
这将立即得到（2010-05-25 07：56：23.000）
SELECT dateadd(s,1274756183,'19700101 05:00:00:000')这样做：
declare @UNIX_TIME int
select @UNIX_TIME = 1111111111
-- Using dateadd to add seconds to 1970-01-01
select [Datetime from UNIX Time] = dateadd(!precision!,@UNIX_TIME,'1970-01-01')而不是！精度！根据时间戳的精度使用：ss，ms或mcs。Bigint能够保持微秒级的精度。
测试一下：
SQL服务器：
SELECT dateadd(S, timestamp, '1970-01-01 00:00:00')
FROM
your_tableMySql服务器：
SELECT
from_unixtime(timestamp)
FROM
your_tablehttp://www.w3resource.com/mysql/date-and-time-functions/mysql-from_unixtime-function.php
加n秒，1970-01-01会给你一个UTC日期，因为ñ，Unix时间戳，是1970年1月1日00:00:00以来协调世界时（UTC）已经过去的秒数，周四。
在SQL Server 2016中，您可以使用将一个时区转换为另一个时区AT TIME ZONE。您只需要知道Windows标准格式的时区名称即可：
SELECT *
FROM (VALUES (1514808000), (1527854400)) AS Tests(UnixTimestamp)
CROSS APPLY (SELECT DATEADD(SECOND, UnixTimestamp, '1970-01-01') AT TIME ZONE 'UTC') AS CA1(UTCDate)
CROSS APPLY (SELECT UTCDate AT TIME ZONE 'Pacific Standard Time') AS CA2(LocalDate)| UnixTimestamp | UTCDate | LocalDate |
|---------------|----------------------------|----------------------------|
| 1514808000 | 2018-01-01 12:00:00 +00:00 | 2018-01-01 04:00:00 -08:00 |
| 1527854400 | 2018-06-01 12:00:00 +00:00 | 2018-06-01 05:00:00 -07:00 |或者简单地：
SELECT *, DATEADD(SECOND, UnixTimestamp, '1970-01-01') AT TIME ZONE 'UTC' AT TIME ZONE 'Pacific Standard Time'
FROM (VALUES (1514808000), (1527854400)) AS Tests(UnixTimestamp)| UnixTimestamp | LocalDate |
|---------------|----------------------------|
| 1514808000 | 2018-01-01 04:00:00 -08:00 |
| 1527854400 | 2018-06-01 05:00:00 -07:00 |笔记：
DATETIMEOFFSET为来截断时区信息DATETIME。这是丹尼尔·利特尔（Daniel Little）为解决此问题所做的工作，但考虑到了夏时制（由于dateadd函数的int限制，日期可用于1902年1月1日及以后）：
我们首先需要创建一个表，该表将存储夏令时的日期范围（来源：美国时间历史）：
CREATE TABLE [dbo].[CFG_DAY_LIGHT_SAVINGS_TIME](
[BEGIN_DATE] [datetime] NULL,
[END_DATE] [datetime] NULL,
[YEAR_DATE] [smallint] NULL
) ON [PRIMARY]
GO
INSERT INTO CFG_DAY_LIGHT_SAVINGS_TIME VALUES
('2001-04-01 02:00:00.000', '2001-10-27 01:59:59.997', 2001),
('2002-04-07 02:00:00.000', '2002-10-26 01:59:59.997', 2002),
('2003-04-06 02:00:00.000', '2003-10-25 01:59:59.997', 2003),
('2004-04-04 02:00:00.000', '2004-10-30 01:59:59.997', 2004),
('2005-04-03 02:00:00.000', '2005-10-29 01:59:59.997', 2005),
('2006-04-02 02:00:00.000', '2006-10-28 01:59:59.997', 2006),
('2007-03-11 02:00:00.000', '2007-11-03 01:59:59.997', 2007),
('2008-03-09 02:00:00.000', '2008-11-01 01:59:59.997', 2008),
('2009-03-08 02:00:00.000', '2009-10-31 01:59:59.997', 2009),
('2010-03-14 02:00:00.000', '2010-11-06 01:59:59.997', 2010),
('2011-03-13 02:00:00.000', '2011-11-05 01:59:59.997', 2011),
('2012-03-11 02:00:00.000', '2012-11-03 01:59:59.997', 2012),
('2013-03-10 02:00:00.000', '2013-11-02 01:59:59.997', 2013),
('2014-03-09 02:00:00.000', '2014-11-01 01:59:59.997', 2014),
('2015-03-08 02:00:00.000', '2015-10-31 01:59:59.997', 2015),
('2016-03-13 02:00:00.000', '2016-11-05 01:59:59.997', 2016),
('2017-03-12 02:00:00.000', '2017-11-04 01:59:59.997', 2017),
('2018-03-11 02:00:00.000', '2018-11-03 01:59:59.997', 2018),
('2019-03-10 02:00:00.000', '2019-11-02 01:59:59.997', 2019),
('2020-03-08 02:00:00.000', '2020-10-31 01:59:59.997', 2020),
('2021-03-14 02:00:00.000', '2021-11-06 01:59:59.997', 2021),
('2022-03-13 02:00:00.000', '2022-11-05 01:59:59.997', 2022),
('2023-03-12 02:00:00.000', '2023-11-04 01:59:59.997', 2023),
('2024-03-10 02:00:00.000', '2024-11-02 01:59:59.997', 2024),
('2025-03-09 02:00:00.000', '2025-11-01 01:59:59.997', 2025),
('1967-04-30 02:00:00.000', '1967-10-29 01:59:59.997', 1967),
('1968-04-28 02:00:00.000', '1968-10-27 01:59:59.997', 1968),
('1969-04-27 02:00:00.000', '1969-10-26 01:59:59.997', 1969),
('1970-04-26 02:00:00.000', '1970-10-25 01:59:59.997', 1970),
('1971-04-25 02:00:00.000', '1971-10-31 01:59:59.997', 1971),
('1972-04-30 02:00:00.000', '1972-10-29 01:59:59.997', 1972),
('1973-04-29 02:00:00.000', '1973-10-28 01:59:59.997', 1973),
('1974-01-06 02:00:00.000', '1974-10-27 01:59:59.997', 1974),
('1975-02-23 02:00:00.000', '1975-10-26 01:59:59.997', 1975),
('1976-04-25 02:00:00.000', '1976-10-31 01:59:59.997', 1976),
('1977-04-24 02:00:00.000', '1977-10-31 01:59:59.997', 1977),
('1978-04-30 02:00:00.000', '1978-10-29 01:59:59.997', 1978),
('1979-04-29 02:00:00.000', '1979-10-28 01:59:59.997', 1979),
('1980-04-27 02:00:00.000', '1980-10-26 01:59:59.997', 1980),
('1981-04-26 02:00:00.000', '1981-10-25 01:59:59.997', 1981),
('1982-04-25 02:00:00.000', '1982-10-25 01:59:59.997', 1982),
('1983-04-24 02:00:00.000', '1983-10-30 01:59:59.997', 1983),
('1984-04-29 02:00:00.000', '1984-10-28 01:59:59.997', 1984),
('1985-04-28 02:00:00.000', '1985-10-27 01:59:59.997', 1985),
('1986-04-27 02:00:00.000', '1986-10-26 01:59:59.997', 1986),
('1987-04-05 02:00:00.000', '1987-10-25 01:59:59.997', 1987),
('1988-04-03 02:00:00.000', '1988-10-30 01:59:59.997', 1988),
('1989-04-02 02:00:00.000', '1989-10-29 01:59:59.997', 1989),
('1990-04-01 02:00:00.000', '1990-10-28 01:59:59.997', 1990),
('1991-04-07 02:00:00.000', '1991-10-27 01:59:59.997', 1991),
('1992-04-05 02:00:00.000', '1992-10-25 01:59:59.997', 1992),
('1993-04-04 02:00:00.000', '1993-10-31 01:59:59.997', 1993),
('1994-04-03 02:00:00.000', '1994-10-30 01:59:59.997', 1994),
('1995-04-02 02:00:00.000', '1995-10-29 01:59:59.997', 1995),
('1996-04-07 02:00:00.000', '1996-10-27 01:59:59.997', 1996),
('1997-04-06 02:00:00.000', '1997-10-26 01:59:59.997', 1997),
('1998-04-05 02:00:00.000', '1998-10-25 01:59:59.997', 1998),
('1999-04-04 02:00:00.000', '1999-10-31 01:59:59.997', 1999),
('2000-04-02 02:00:00.000', '2000-10-29 01:59:59.997', 2000)
GO现在，我们为每个美国时区创建一个函数。这是假设Unix时间以毫秒为单位。如果以秒为单位，请从代码中删除/ 1000：
太平洋地区
create function [dbo].[UnixTimeToPacific]
(@unixtime bigint)
returns datetime
as
begin
declare @pacificdatetime datetime
declare @interimdatetime datetime = dateadd(s, @unixtime/1000, '1970-01-01')
select @pacificdatetime = dateadd(hour,case when @interimdatetime between begin_date and end_date then -7 else -8 end ,@interimdatetime)
from cfg_day_light_savings_time where year_date = datepart(year,@interimdatetime)
if @pacificdatetime is null
select @pacificdatetime= dateadd(hour, -7, @interimdatetime)
return @pacificdatetime
end东
create function [dbo].[UnixTimeToEastern]
(@unixtime bigint)
returns datetime
as
begin
declare @easterndatetime datetime
declare @interimdatetime datetime = dateadd(s, @unixtime/1000, '1970-01-01')
select @easterndatetime = dateadd(hour,case when @interimdatetime between begin_date and end_date then -4 else -5 end ,@interimdatetime)
from cfg_day_light_savings_time where year_date = datepart(year,@interimdatetime)
if @easterndatetime is null
select @easterndatetime= dateadd(hour, -4, @interimdatetime)
return @easterndatetime
end中央
create function [dbo].[UnixTimeToCentral]
(@unixtime bigint)
returns datetime
as
begin
declare @centraldatetime datetime
declare @interimdatetime datetime = dateadd(s, @unixtime/1000, '1970-01-01')
select @centraldatetime = dateadd(hour,case when @interimdatetime between begin_date and end_date then -5 else -6 end ,@interimdatetime)
from cfg_day_light_savings_time where year_date = datepart(year,@interimdatetime)
if @centraldatetime is null
select @centraldatetime= dateadd(hour, -5, @interimdatetime)
return @centraldatetime
end山
create function [dbo].[UnixTimeToMountain]
(@unixtime bigint)
returns datetime
as
begin
declare @mountaindatetime datetime
declare @interimdatetime datetime = dateadd(s, @unixtime/1000, '1970-01-01')
select @mountaindatetime = dateadd(hour,case when @interimdatetime between begin_date and end_date then -6 else -7 end ,@interimdatetime)
from cfg_day_light_savings_time where year_date = datepart(year,@interimdatetime)
if @mountaindatetime is null
select @mountaindatetime= dateadd(hour, -6, @interimdatetime)
return @mountaindatetime
end夏威夷
create function [dbo].[UnixTimeToHawaii]
(@unixtime bigint)
returns datetime
as
begin
declare @hawaiidatetime datetime
declare @interimdatetime datetime = dateadd(s, @unixtime/1000, '1970-01-01')
select @hawaiidatetime = dateadd(hour,-10,@interimdatetime)
from cfg_day_light_savings_time where year_date = datepart(year,@interimdatetime)
return @hawaiidatetime
end亚利桑那
create function [dbo].[UnixTimeToArizona]
(@unixtime bigint)
returns datetime
as
begin
declare @arizonadatetime datetime
declare @interimdatetime datetime = dateadd(s, @unixtime/1000, '1970-01-01')
select @arizonadatetime = dateadd(hour,-7,@interimdatetime)
from cfg_day_light_savings_time where year_date = datepart(year,@interimdatetime)
return @arizonadatetime
end阿拉斯加州
create function [dbo].[UnixTimeToAlaska]
(@unixtime bigint)
returns datetime
as
begin
declare @alaskadatetime datetime
declare @interimdatetime datetime = dateadd(s, @unixtime/1000, '1970-01-01')
select @alaskadatetime = dateadd(hour,case when @interimdatetime between begin_date and end_date then -8 else -9 end ,@interimdatetime)
from cfg_day_light_savings_time where year_date = datepart(year,@interimdatetime)
if @alaskadatetime is null
select @alaskadatetime= dateadd(hour, -8, @interimdatetime)
return @alaskadatetime
end//BIGINT UNIX TIMESTAMP CONVERSION upto Millisecond Accuracy
CREATE FUNCTION [dbo].[ConvertUnixTimestamp] (@Datetime [BIGINT]) RETURNS DATETIME
AS
BEGIN
RETURN DATEADD(MILLISECOND, cast(@Datetime as bigint) % 1000,
DATEADD(SECOND, (cast(@Datetime as bigint) / 1000)%60,
DATEADD(MINUTE, ((cast(@Datetime as bigint) / 1000)/60)%60,
DATEADD(HOUR, ((cast(@Datetime as bigint) / 1000)/60)/60, '19700101'))))
END我也不得不面对这个问题。不幸的是，没有一个答案（在这里和其他数十页中）令我满意，因为由于某个地方有32位整数强制转换，所以我仍然无法达到2038年以后的日期。
最终对我有用的解决方案是使用float变量，因此我的最大日期至少为2262-04-11T23:47:16.854775849。尽管如此，这并不能覆盖整个datetime领域，但足以满足我的需求，并且可以帮助其他遇到相同问题的人。
-- date variables
declare @ts bigint; -- 64 bit time stamp, 100ns precision
declare @d datetime2(7) = GETUTCDATE(); -- 'now'
-- select @d = '2262-04-11T23:47:16.854775849'; -- this would be the max date
-- constants:
declare @epoch datetime2(7) = cast('1970-01-01T00:00:00' as datetime2(7));
declare @epochdiff int = 25567; -- = days between 1900-01-01 and 1970-01-01
declare @ticksofday bigint = 864000000000; -- = (24*60*60*1000*1000*10)
-- helper variables:
declare @datepart float;
declare @timepart float;
declare @restored datetime2(7);
-- algorithm:
select @ts = DATEDIFF_BIG(NANOSECOND, @epoch, @d) / 100; -- 'now' in ticks according to unix epoch
select @timepart = (@ts % @ticksofday) / @ticksofday; -- extract time part and scale it to fractional part (i. e. 1 hour is 1/24th of a day)
select @datepart = (@ts - @timepart) / @ticksofday; -- extract date part and scale it to fractional part
select @restored = cast(@epochdiff + @datepart + @timepart as datetime); -- rebuild parts to a datetime value
-- query original datetime, intermediate timestamp and restored datetime for comparison
select
@d original,
@ts unix64,
@restored restored
;
-- example result for max date:
-- +-----------------------------+-------------------+-----------------------------+
-- | original | unix64 | restored |
-- +-----------------------------+-------------------+-----------------------------+
-- | 2262-04-11 23:47:16.8547758 | 92233720368547758 | 2262-04-11 23:47:16.8533333 |
-- +-----------------------------+-------------------+-----------------------------+需要考虑以下几点：
@ticksofday算法的第一行。1900-01-01是的起始日期datetime2，就像1970-01-01unix时间戳记的纪元一样。floats帮助我解决了2038年的问题和整数溢出等问题，但请记住，浮点数的性能不是很高，并且可能会减慢处理大量时间戳的速度。同样，由于舍入误差，浮点数可能会导致精度降低，如您在上面的最大日期的示例结果的比较中可以看到的那样（此处的误差约为1.4425毫秒）。datetime。不幸的是，没有从数字值到datetime2允许的显式转换，但允许将数字datetime显式地转换为，而这又隐式地转换为datetime2。暂时来说这可能是正确的，但是在SQL Server的未来版本中可能会发生变化：要么存在dateadd_big()函数，要么datetime2允许使用显式datetime强制转换，或者不允许显式强制转换，所以这可能会中断或可能出现有一天更简单的方法。更好？此函数将以毫秒为单位的unixtime转换为datetime。它损失了毫秒，但对于过滤仍然非常有用。
CREATE FUNCTION [dbo].[UnixTimestampToGMTDatetime]
(@UnixTimestamp bigint)
RETURNS datetime
AS
BEGIN
DECLARE @GMTDatetime datetime
select @GMTDatetime =
CASE
WHEN dateadd(ss, @UnixTimestamp/1000, '1970-01-01')
BETWEEN
Convert(DATETIME, Convert(VARCHAR(4), Year(dateadd(ss, @UnixTimestamp/1000, '1970-01-01') )) + '-03-' + Convert(VARCHAR(2), (31 - (5 * Year(dateadd(ss, @UnixTimestamp/1000, '1970-01-01') )/4 + 4) % 7)) + ' 01:00:00', 20)
AND
Convert(DATETIME, Convert(VARCHAR(4), Year(dateadd(ss, @UnixTimestamp/1000, '1970-01-01') )) + '-10-' + Convert(VARCHAR(2), (31 - (5 * Year(dateadd(ss, @UnixTimestamp/1000, '1970-01-01') )/4 + 1) % 7)) + ' 02:00:00', 20)
THEN Dateadd(hh, 1, dateadd(ss, @UnixTimestamp/1000, '1970-01-01'))
ELSE Dateadd(hh, 0, dateadd(ss, @UnixTimestamp/1000, '1970-01-01'))
END
RETURN @GMTDatetime
END解决方案可以如下：
DECLARE @UnixTimeStamp bigint = 1564646400000 /*2019-08-01 11:00 AM*/
DECLARE @LocalTimeOffset bigint = DATEDIFF(MILLISECOND, GETDATE(), GETUTCDATE());
DECLARE @AdjustedTimeStamp bigint = @UnixTimeStamp - @LocalTimeOffset;
SELECT [DateTime] = DATEADD(SECOND, @AdjustedTimeStamp % 1000, DATEADD(SECOND, @AdjustedTimeStamp / 1000, '19700101'));@DanielLittle对特定问题有最简单，最优雅的答案。但是，如果您有兴趣转换到特定的时区并考虑DST（夏令时），则可以很好地进行以下操作：
CAST(DATEADD(S, [UnixTimestamp], '1970-01-01') AT TIME ZONE 'UTC' AT TIME ZONE 'Pacific Standard Time' AS Datetime)注意：此解决方案仅适用于SQL Server 2016及更高版本（和Azure）。
创建函数：
CREATE FUNCTION dbo.ConvertUnixTime (@input INT)
RETURNS Datetime
AS BEGIN
DECLARE @Unix Datetime
SET @Unix = CAST(DATEADD(S, @Input, '1970-01-01') AT TIME ZONE 'UTC' AT TIME ZONE 'Pacific Standard Time' AS Datetime)
RETURN @Unix
END您可以像这样调用该函数：
SELECT dbo.ConvertUnixTime([UnixTimestamp])
FROM YourTable