如何使用 datediff 将 datetime2 列转换为 bigint

Question

我有一个名为 'order_confirmation_date' 的列，它采用 Datetime2 格式，我需要它与 bigint 配合使用以下查询，该查询使用 datediff b/w 列值和 getdate()。

SELECT 
   datediff(day, convert(VARCHAR(10), 
   NULLIF((                                             
       CASE WHEN cast(replace(convert(varchar(10),cast(fpo.order_confirmation_date as date)),'-','') as bigint) >= cast([dbo].[fnGetFormatedDate](getdate(), 'YYYYMMDD') AS BIGINT)

            THEN fpo.order_confirmation_date                                                
            ELSE NULL

            END
                                        ), 0),112), GETDATE()) * (- 1) AS ordconf_x_days_fromtoday
    FROM bidb.fact_purchase_order fpo

Msg 50000, Level 16, State 2, Line 1409 Operand type clash: datetime2 is incompatible with bigint

Answer 1

你已经有约会了。别那么辛苦了，让你的约会对象成为约会对象吧。

declare @t table (order_confirmation_date datetime2);
insert @t 
values ('20190524'),('20190722'),(CAST(GETDATE() AS date))

SELECT 
  fpo.order_confirmation_date,
  datediff(day, CAST(getdate() AS date),fpo.order_confirmation_date)
 AS ordconf_x_days_fromtoday
FROM @t fpo

结果：

+-----------------------------+--------------------------+
|   order_confirmation_date   | ordconf_x_days_fromtoday |
+-----------------------------+--------------------------+
| 2019-05-24 00:00:00.0000000 |                      -19 |
| 2019-07-22 00:00:00.0000000 |                       40 |
| 2019-06-12 00:00:00.0000000 |                        0 |
+-----------------------------+--------------------------+

编辑： 如果你想要过去的日期 return NULL:

SELECT 
  fpo.order_confirmation_date,
  CASE 
    WHEN fpo.order_confirmation_date < GETDATE() THEN NULL
    ELSE datediff(day, CAST(getdate() AS date),fpo.order_confirmation_date)
  END AS ordconf_x_days_fromtoday
FROM @t fpo

如何使用 datediff 将 datetime2 列转换为 bigint

How to convert datetime2 column to bigint with the datediff in place

sql-server

date-conversion

bigint

datetime2