[英]SQL Server OUTPUT clause
我有點陷入困境,為什么我似乎無法通過下面的語句獲得插入行的“新標識”。 SCOPE_IDENTITY()
只返回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)
任何援助都將非常感激。
現在我使用這樣的解決方法。
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
編輯於2013年2月
@MartinSmith提醒我們,這個bug 不想被Microsoft修復 。
“微軟發布於2013年2月27日下午2:18你好Martin,我們調查了這個問題並發現改變行為並不是一件容易的事情。它基本上需要在INSERT和OUTPUT時重新定義一些行為INTO目標有標識列。鑒於問題的性質和不常見的情況,我們決定不解決問題。 - Umachandar,SQL可編程性團隊“
2012年10月編輯
這是由一個錯誤造成的:
測試錯誤:
@@ IDENTITY,SCOPE_IDENTITY和IDENT_CURRENT返回僅由嵌套DML語句生成的標識值,而不是由外部INSERT語句生成的標識值。
測試之后似乎scope_identity()僅在外部操作是具有標識列的表中的插入時才有效:
測試1:刪除
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
測試2: 在外表中插入標識
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
測試3:在沒有標識的外表中插入
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
您可能嘗試使用表變量作為output
子句,從而允許您顯式插入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)
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