看MSDN:
http://msdn.microsoft.com/zh-cn/library/ms187331.aspx
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。
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
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
代码如下:
BEGIN
WAITFOR DELAY '02:00';
EXECUTE sp_helpdb;
END;
GO
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。
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
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
执行结果：A total time of 00:00:10,in hh:mm:ss,has elapsed.Your time is up.小结：这是一种轻巧的解决方案。当你没有权限指定job时，可以考虑用WaitFor语句。
邀月注：本文版权由邀月和博客园共同所有，转载请注明出处。 原文链接：https://www.f2er.com/mssql/66189.html
