将.NET Ticks转换为SQL Server DateTime

Question

我TimeSpan在我的数据库中保存一个(来自.NET)值,就像BIGINT在SQL Server中一样(保存Ticks属性).我想知道如何将此BIGINT值转换为DATETIMESQL Server中的值(而不是在.NET中).有任何想法吗？

干杯

编辑:

我正在使用NHibernate来映射TimeSpan我拥有的属性,并且它持久存在Ticks属性.我用它来控制某个日期的相对小时(或分钟).

在系统内部一切都很好,不需要这种转换.但是,在SQL Server中执行随机查询时,很难理解a的持久形式TimeSpan.因此,我传递Ticks值并DateTime返回a的函数将给出表示的小时,分​​钟和秒的数量TimeSpan.

Answer 1

我不确定秒数会有多准确,但您可以尝试以下方法:

Declare @TickValue bigint
Declare @Days float

Set @TickValue = 634024345696365272 
Select @Days = @TickValue * POWER(10.00000000000,-7) / 60 / 60 / 24

Select DATEADD(d, Cast(@Days As int), Cast('0001-01-01' As DATE)) 
    + Cast( (@Days - FLOOR(@Days)) As DateTime)

实际上,在SQL 2005中可以使用的另一种方法是注意,从0001-01-01到1900-01-01的刻度数是599266080000000000.有了这个,您可以这样做:

Declare @TickOf19000101 bigint
Declare @TickValue bigint
Declare @Minutes float

Set @TickOf19000101  = 599266080000000000
Set @TickValue = DATEDIFF(mi, 0 ,CURRENT_TIMESTAMP) * Cast(60 As BigInt) 
                   * POWER(10.00000000000,7) + @TickOf19000101

Select @TickValue
Select @Minutes = (@TickValue - @TickOf19000101) * POWER(10.00000000000,-7) / 60

Select @Minutes
Select DATEADD(MI, @Minutes, '1900-01-01')

Answer 2

我真的不知道SQL Server,但今天我的同事遇到了同样的问题,我想我找到了这样的解决方案:

CAST(([ticks] - 599266080000000000) / 10000000 / 24 / 60 / 60 AS datetime)

其中599266080000000000是01/01/1900 00:00:00的刻度值.

Answer 3

您可以使用Pavel Gatilov博客中的此函数将64位整数转换为服务器本地时间内具有毫秒精度的日期时间值:

CREATE FUNCTION NetFxUtcTicksToDateTime
(
   @Ticks bigint
)
RETURNS datetime
AS
BEGIN

-- First, we will convert the ticks into a datetime value with UTC time
DECLARE @BaseDate datetime;
SET @BaseDate = '01/01/1900';

DECLARE @NetFxTicksFromBaseDate bigint;
SET @NetFxTicksFromBaseDate = @Ticks - 599266080000000000;
-- The numeric constant is the number of .Net Ticks between the System.DateTime.MinValue (01/01/0001) and the SQL Server datetime base date (01/01/1900)

DECLARE @DaysFromBaseDate int;
SET @DaysFromBaseDate = @NetFxTicksFromBaseDate / 864000000000;
-- The numeric constant is the number of .Net Ticks in a single day.

DECLARE @TimeOfDayInTicks bigint;
SET @TimeOfDayInTicks = @NetFxTicksFromBaseDate - @DaysFromBaseDate * 864000000000;

DECLARE @TimeOfDayInMilliseconds int;
SET @TimeOfDayInMilliseconds = @TimeOfDayInTicks / 10000;
-- A Tick equals to 100 nanoseconds which is 0.0001 milliseconds

DECLARE @UtcDate datetime;
SET @UtcDate = DATEADD(ms, @TimeOfDayInMilliseconds, DATEADD(d, @DaysFromBaseDate, @BaseDate));
-- The @UtcDate is already useful. If you need the time in UTC, just return this value.

-- Now, some magic to get the local time
RETURN @UtcDate + GETDATE() - GETUTCDATE();
END
GO

适用于内联使用的替代代码:

DECLARE @Ticks bigint
set @Ticks = 634899090000000000
select DATEADD(ms, ((@Ticks - 599266080000000000) - 
   FLOOR((@Ticks - 599266080000000000) / 864000000000) * 864000000000) / 10000,
   DATEADD(d, (@Ticks - 599266080000000000) / 864000000000, '01/01/1900')) +
   GETDATE() - GETUTCDATE()

Answer 4

A TimeSpan不是日期,因此保存它可能会在将来引起混淆.

有没有理由你不能简单地将刻度保存到整数字段而不改变其含义？