SQL Server 乐观锁定 - 返回更改的时间戳值

Question

我有一个实现乐观锁定的更新存储过程。存储过程如下所示:

ALTER PROCEDURE [dbo].[usp_Test] 
    @Id AS char(2),
       @recordTimestamp as timestamp
       ...
BEGIN       
    UPDATE XY
           ..
          WHERE ((Id = @Id) AND (recordTimeStamp = @recordTimestamp))       

if @@rowcount = 0
begin
RAISERROR ('this row was changed by another user', 18, 1)
end

SELECT timeStamp from XY where Id = @Idend

有没有更简单的方法来返回新的时间戳？我真的很想避免 SELECT 语句。

Answer 1

假设至少 SQL Server 2005 可以使用 OUTPUT

UPDATE XY
SET Col = 'foo'
OUTPUT inserted.recordTimeStamp
WHERE ((Id = @Id) AND (recordTimeStamp = @recordTimestamp))    

或者使用表变量更接近地反射(reflect)原始查询行为的版本。

DECLARE @Timestamp TABLE(stamp binary(8))

UPDATE XY
SET col='foo'
OUTPUT inserted.recordTimeStamp INTO @Timestamp
WHERE (Id = @Id) AND (recordTimeStamp = @recordTimestamp) 

if @@rowcount = 0
begin
RAISERROR ('this row was changed by another user', 18, 1)
end

SELECT stamp 
FROM @Timestamp