SQL Server的OUTPUT子句(SQL Server OUTPUT clause)

我有点坚持了为什么我似乎无法得到插入行的“新身份”与下面的语句。 SCOPE_IDENTITY()刚刚返回null。

declare @WorkRequestQueueID int
declare @LastException nvarchar(MAX)
set @WorkRequestQueueID = 1
set @LastException = 'test'

set nocount off

DELETE dbo.WorkRequestQueue
OUTPUT
        DELETED.MessageEnvelope,
        DELETED.Attempts,
        @LastException,
        GetUtcdate(), -- WorkItemPoisened datetime
        DELETED.WorkItemReceived_UTC
    INTO dbo.FaildMessages
FROM dbo.WorkRequestQueue
WHERE
    WorkRequestQueue.ID = @WorkRequestQueueID

IF @@ROWCOUNT = 0 
  RAISERROR ('Record not found', 16, 1) 

SELECT Cast(SCOPE_IDENTITY() as int) 

任何援助将非常感激。

现在我用这个解决方法，像这样。

declare     @WorkRequestQueueID int
declare @LastException nvarchar(MAX)
set @WorkRequestQueueID = 7
set @LastException = 'test'

set nocount on
set xact_abort on 

DECLARE @Failed TABLE 
(
    MessageEnvelope xml, 
    Attempts smallint,
    LastException nvarchar(max),
    WorkItemPoisened_UTC datetime,
    WorkItemReceived_UTC datetime
)

BEGIN TRAN

DELETE dbo.WorkRequestQueue
OUTPUT
    DELETED.MessageEnvelope,
    DELETED.Attempts,
    @LastException,
    GetUtcdate(), -- WorkItemPoisened datetime
    DELETED.WorkItemReceived_UTC

INTO 
    @Failed
FROM 
    dbo.WorkRequestQueue
WHERE
    WorkRequestQueue.ID = @WorkRequestQueueID

IF @@ROWCOUNT = 0 BEGIN  
    RAISERROR ('Record not found', 16, 1) 
    Rollback
END ELSE BEGIN
    insert into dbo.FaildMessages select * from @Failed
    COMMIT TRAN
    SELECT Cast(SCOPE_IDENTITY() as int) 
END

Answer 1:

你可以尝试使用表变量为您output条款，从而使您可以明确地插入FaildMessages ：

declare     @WorkRequestQueueID int
declare @LastException nvarchar(MAX)
set @WorkRequestQueueID = 1
set @LastException = 'test'

set nocount off

    -- Declare a table variable to capture output
    DECLARE @output TABLE (
        MessageEnvelope VARCHAR(50),    -- Guessing at datatypes
        Attempts INT,                   -- Guessing at datatypes
        WorkItemReceived_UTC DATETIME   -- Guessing at datatypes
    )

    -- Run the deletion with output
    DELETE dbo.WorkRequestQueue
    OUTPUT
        DELETED.MessageEnvelope,
        DELETED.Attempts,
        DELETED.WorkItemReceived_UTC
    -- Use the table var
    INTO @output
    FROM dbo.WorkRequestQueue
    WHERE
        WorkRequestQueue.ID = @WorkRequestQueueID

    -- Explicitly insert
    INSERT
    INTO dbo.FaildMessages
    SELECT
        MessageEnvelope,
        Attempts,
        @LastException,
        GetUtcdate(), -- WorkItemPoisened datetime
        WorkItemReceived_UTC
    FROM @output


IF @@ROWCOUNT = 0 
  RAISERROR ('Record not found', 16, 1)


SELECT Cast(SCOPE_IDENTITY() as int) 

Answer 2:

EDITED FEB'2013

@MartinSmith提醒我们，这个错误不希望被微软定 。

“发布Microsoft在2013年2月27日在下午2时18分您好马丁，我们调查这个问题，并发现，改变的行为不是一件容易的事。这将基本上都需要进行重新定义一些行为当两个INSERT和输出的。INTO目标具有标识列鉴于问题和不凡的情形的性质，我们已经决定不解决这个问题 - Umachandar，SQL可编程性团队”

EDITED OCT'2012

这是由错误引起的：

测试错误：

引用OUTPUT子句文档 ：

只有嵌套DML语句生成@@ IDENTITY，SCOPE_IDENTITY和IDENT_CURRENT返回标识值，而不是那些由外部INSERT语句生成。

测试后，它似乎SCOPE_IDENTITY（）只有当外部运行与身份列的表的插入的工作原理：

测试1：删除

create table #t ( a char(1) );
create table #d ( a char(1), i int identity );

insert into #t
values ('a'),('b'),('c');

delete #t
output deleted.a into #d;

select SCOPE_IDENTITY(), * from #d;

     a i 
---- - - 
null a 1 
null b 2 
null c 3 

测试2： 与身份外表中插入

create table #t ( a char(1), i int identity );
create table #d ( a char(1), i int identity );

insert into #t
values  ('x'),('x'),('x');

insert into #t
output inserted.a into #d
values  ('a'),('b');

select scope_identity(), * from #d;

  a i 
- - - 
2 a 1 
2 b 2 

测试3：无标识外表中插入

create table #t ( a char(1) );
create table #d ( a char(1), i int identity );

insert into #t
values  ('x'),('x'),('x');

insert into #t
output inserted.a into #d
values  ('a'),('b');

select scope_identity(), * from #d;


     a i 
---- - - 
null a 1 
null b 2 

文章来源: SQL Server OUTPUT clause