SQL Server 2008中SQL之WaitFor使用介绍

2024-08-31 01:00:51

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看MSDN:

语法为：

WAITFOR
{
DELAY 'time_to_pass'
| TIME 'time_to_execute'
| [ ( receive_statement ) | ( get_conversation_group_statement ) ]
[ , TIMEOUT timeout ]
}

以下示例在晚上 10:20 (22:20) 执行存储过程 sp_update_job。

复制代码代码如下:

USE msdb;
EXECUTE sp_add_job @job_name = 'TestJob';
BEGIN
WAITFOR TIME '22:20';
EXECUTE sp_update_job @job_name = 'TestJob',
@new_name = 'UpdatedJob';
END;
GO

以下示例在两小时的延迟后执行存储过程。注意:Delay最多不超过24小时

复制代码代码如下:

BEGIN
WAITFOR DELAY '02:00';
EXECUTE sp_helpdb;
END;
GO

以下示例显示如何对 WAITFOR DELAY 选项使用局部变量。将创建一个存储过程，该过程将等待可变的时间段，然后将经过的小时、分钟和秒数信息返回给用户。

复制代码代码如下:

USE AdventureWorks2008R2;
GO
IF OBJECT_ID('dbo.TimeDelay_hh_mm_ss','P') IS NOT NULL
DROP PROCEDURE dbo.TimeDelay_hh_mm_ss;
GO
CREATE PROCEDURE dbo.TimeDelay_hh_mm_ss
(
@DelayLength char(8)= '00:00:00'
)
AS
DECLARE @ReturnInfo varchar(255)
IF ISDATE('2000-01-01 ' + @DelayLength + '.000') = 0
BEGIN
SELECT @ReturnInfo = 'Invalid time ' + @DelayLength
+ ',hh:mm:ss, submitted.';
-- This PRINT statement is for testing, not use in production.
PRINT @ReturnInfo
RETURN(1)
END
BEGIN
WAITFOR DELAY @DelayLength
SELECT @ReturnInfo = 'A total time of ' + @DelayLength + ',
hh:mm:ss, has elapsed! Your time is up.'
-- This PRINT statement is for testing, not use in production.
PRINT @ReturnInfo;
END;
GO
/* This statement executes the dbo.TimeDelay_hh_mm_ss procedure. */
EXEC TimeDelay_hh_mm_ss '00:00:10';
GO