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应用场景：
在庞大的数据库中很多复杂的更新查询非常的耗时。为了避免用户长时间的等待，那些耗时的操作可以采用异步执行的方法，立刻返回执行信息给用户，同时在数据库后台执行操作，等到执行完毕再更新数据表。
开发环境：
SQL SERVER2000 .NET
解决方案：
在SQL SERVER2000中创建一个临时的Job，（或者固定的Job，根据具体的应用场景），传递需要执行的SQL batch脚本，然后启动这个Job。这样就可以在数据库获得异步调用的功能了。由于创建的是临时的Job，
SQL SERVER在该Job运行结束以后会自动删除该Job。
缺点：该存储过程必须指定数据库的名字
====================================================================================
/******************************************************************************
* Author: iret
* Desc: Create temporary job to provide asynchronously invoking SQL batch
* 在SQL SERVER 2000中创建用于执行异步调用的临时Job
* @EXECSQL: Transact-SQL batch
* Eample: EXEC dbo.AsynchronousInvoking @EXECSQL = 'UPDTAE customer SET balance = 0'
* 缺点：该存储过程必须指定数据库的名字
* Modified Date: 2004/11/03
******************************************************************************/
CREATE Procedure dbo.AsynchronousInvoking
@EXECSQL nvarchar(4000)
AS
BEGIN TRANSACTION
DECLARE @JobID BINARY(16)
DECLARE @ReturnCode INT
SELECT @ReturnCode = 0
BEGIN
-- Add the job
EXECUTE @ReturnCode = msdb.dbo.sp_add_job @job_id = @JobID OUTPUT ,
@job_name = N'temp_sqljob',
@owner_login_name = N'',
@description = N'description for job', -- the description of the job
@category_name = N'[Uncategorized (Local)]',
@enabled = 1,
@notify_level_email = 0,
@notify_level_page = 0,
@notify_level_netsend = 0,
@notify_level_eventlog = 0,
@delete_level= 3
IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback
-- Add the job steps
EXECUTE @ReturnCode = msdb.dbo.sp_add_jobstep @job_id = @JobID,
@step_id = 1,
@step_name = N'step1',
@command = @EXECSQL, -- sql batch
--缺点：该存储过程必须指定数据库的名字
@database_name = N'your_database_name', --the database name of the job to manipulate
@server = N'',
@database_user_name = N'appuser',
@subsystem = N'TSQL',
@cmdexec_success_code = 0,
@flags = 0,
@retry_attempts = 0, --execute once only
@retry_interval = 0,
@output_file_name = N'',
@on_success_step_id = 0,
@on_success_action = 1, -- on success abort
@on_fail_step_id = 0,
@on_fail_action = 2 -- on fail abort
IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback
--set the star step id of the job
EXECUTE @ReturnCode = msdb.dbo.sp_update_job @job_id = @JobID,
@start_step_id = 1
IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback
-- Add the Target Servers
EXECUTE @ReturnCode = msdb.dbo.sp_add_jobserver @job_id = @JobID,
@server_name = N'(local)'
IF (@@ERROR <> 0 OR @ReturnCode <> 0) GOTO QuitWithRollback
END
COMMIT TRANSACTION
GOTO EndSave
QuitWithRollback:
IF (@@TRANCOUNT > 0) BEGIN
ROLLBACK TRANSACTION
RETURN 1
END
EndSave:
--star the job immediately
EXEC @ReturnCode = msdb.dbo.sp_start_job @job_id = @JobID
--return to the invoker immediately
RETURN @ReturnCode
GO
SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO
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