Select * 来自 Convert(date, DueDate) = @today 的项目

Question

我在使用简单的 select 时遇到了问题。存储 DueDate 的数据库字段是 DateTimeOffset。

 declare @today Date = GetDate();
 Select * from Items where Convert(date, DueDate) = @today

这似乎工作到深夜，此时 returns 行实际上是第二天到期的。

问题：GetDate()，因为它是 Azure 上的 Sql 服务器运行，实际上是 returns GetUTCDate()。所以在美国东部时间晚上 9 点，returns 不是今天，而是明天，因为 UTC 时间提前 5 小时（凌晨 2 点，第二天）。

我已将 @today 设为日期，以便可以忽略时间部分。

但是在数据库中，DueDate是2018-12-02 05:00:00.0000000 +00:00但是当这个转换为日期时，日期是2018-12-02，但是@today是2018-12-03

那我应该怎么写SQL？

Answer 1

您需要将“今天”放入时区，考虑下面的 2 个查询（注意“今天”是如何设置的）参见 AT TIME ZONE:

declare @today as datetimeoffset;
SET @today = cast(getdate() as date);

;with Items as (
    select -24 as n, dateadd(hour,-24,SYSDATETIMEOFFSET()) as DueDate
    
    union all
    
    select n+1, dateadd(hour,n+1,SYSDATETIMEOFFSET())
    from Items
    where n < 24
    )

Select * , @today
from Items 
where DueDate >= @today and DueDate < dateadd(day,1,@today)
;

GO

  n | DueDate                    | (No column name)          
--: | :------------------------- | :-------------------------
-10 | 03/12/2018 00:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 -9 | 03/12/2018 01:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 -8 | 03/12/2018 02:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 -7 | 03/12/2018 03:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 -6 | 03/12/2018 04:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 -5 | 03/12/2018 05:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 -4 | 03/12/2018 06:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 -3 | 03/12/2018 07:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 -2 | 03/12/2018 08:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 -1 | 03/12/2018 09:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  0 | 03/12/2018 10:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  1 | 03/12/2018 11:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  2 | 03/12/2018 12:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  3 | 03/12/2018 13:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  4 | 03/12/2018 14:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  5 | 03/12/2018 15:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  6 | 03/12/2018 16:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  7 | 03/12/2018 17:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  8 | 03/12/2018 18:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
  9 | 03/12/2018 19:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 10 | 03/12/2018 20:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 11 | 03/12/2018 21:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 12 | 03/12/2018 22:57:54 +00:00 | 03/12/2018 00:00:00 +00:00
 13 | 03/12/2018 23:57:54 +00:00 | 03/12/2018 00:00:00 +00:00

declare @today as datetimeoffset;
SET @today = cast(cast(getdate() as date) as datetimeoffset) AT TIME ZONE 'Pacific Standard Time';

;with Items as (
    select -24 as n, dateadd(hour,-24,SYSDATETIMEOFFSET()) as DueDate
    
    union all
    
    select n+1, dateadd(hour,n+1,SYSDATETIMEOFFSET())
    from Items
    where n < 24
    )

Select * , @today
from Items 
where DueDate >= @today and DueDate < dateadd(day,1,@today)
;

GO

  n | DueDate                    | (No column name)          
--: | :------------------------- | :-------------------------
-10 | 03/12/2018 00:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 -9 | 03/12/2018 01:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 -8 | 03/12/2018 02:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 -7 | 03/12/2018 03:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 -6 | 03/12/2018 04:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 -5 | 03/12/2018 05:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 -4 | 03/12/2018 06:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 -3 | 03/12/2018 07:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 -2 | 03/12/2018 08:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 -1 | 03/12/2018 09:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  0 | 03/12/2018 10:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  1 | 03/12/2018 11:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  2 | 03/12/2018 12:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  3 | 03/12/2018 13:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  4 | 03/12/2018 14:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  5 | 03/12/2018 15:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  6 | 03/12/2018 16:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  7 | 03/12/2018 17:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  8 | 03/12/2018 18:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
  9 | 03/12/2018 19:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 10 | 03/12/2018 20:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 11 | 03/12/2018 21:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 12 | 03/12/2018 22:57:54 +00:00 | 02/12/2018 16:00:00 -08:00
 13 | 03/12/2018 23:57:54 +00:00 | 02/12/2018 16:00:00 -08:00

db<>fiddle here

Select * 来自 Convert(date, DueDate) = @today 的项目

Select * from Items where Convert(date, DueDate) = @today

sql

sql-server

sql-server-2017