我创建了一个新的 SSIS 包 (SQL 2017)，它读取“导出请求”表并根据计划将数据导出到外部存储。例如，用户可以向该表添加一个新行，如“select * from table 1 where col1=2”，时间表为 2018 年 6 月 25 日下午 3:30。
我的包（使用 SQL 代理运行）一直循环以在该表中搜索新任务，并在计划时将查询结果导出到当时的文件夹。
有一项新功能要求将这些导出安排为重复出现。例如，客户可能希望从 2018 年 6 月 25 日下午 3:30 开始每天进行导出。每年、每月、每天、每 3 个月的日程安排可能会变得复杂......
在 SSIS 中实现循环的最佳方式是什么？我可以为 Cron 使用 5 个字符的字段，但不知道如何使用他们的 Cron 计划查询新任务。 有什么帮助吗？
【问题讨论】：
确认您已经拥有的内容：您有一个 TASK 表，其中包含任务以及需要运行的某种日期标志。然后，您的作业每 x 分钟运行一次，并检查是否有任何任务要执行/运行。如果是这样，它会运行它们。然后我猜你在你设置的表中有一个标志，说它在你在循环中运行后完成？如果您一次要运行多个任务，它一次只运行一个？
然后你想要做的就是添加这个：我做了一些非常相似的事情。我为每个任务创建了一个查找表（在我的流程中，每个任务都有一个名称，我使用该名称来引用查找表，我称之为调度查找）。
在该表中，我列出了报告需要运行的时间和频率（所以 2 列）一天中的时间和频率。一个例子是 7:00 和工作日。因此，对于此报告，它仅在每个工作日 (m-F) 和晚上 7 点运行。
然后，当我的作业运行时，它会像您上面那样运行任务，但随后会有另一个步骤，将该任务标记为已完成，然后在任务表中插入一个新任务（任务详细信息将相同) 但我会查看上面描述的日程表查找表，以确定作业应该再次运行的下一个日期/时间，并将其用作我的任务表中的下一个运行日期/时间。
以下是我在流程中使用的 SP，用于获取下一个计划日期/时间并将现有的更新为已完成，然后创建新的。
注意：我的日程安排有一些您可能不需要的高级选项，我有很多 cmets 应该解释我在做什么/为什么要做所有事情。我正在调用我在某些地方创建的一些函数，但我认为您不需要这些函数，并且可以弄清楚要做什么而不是我的函数，但是如果您有问题，请告诉我：
这是我使用的，所以它使用我的表结构/等，但你可以很容易地将它转换为你的。
--Purpose
----------------------------------------------------------------------------------
-- calculates the next time to run/schedule the job
----------------------------------------------------------------------------------
-- NOTE: TO USE you have to insert the first value manually in queue table
----- possibile scenerios
-- if we want to schedule every x hours, or x days
-- run every month only
-- run weekdays only
-- run on certain days of month only
-- TO ADD MORE COMPLEX or different types of schedules:
-- special - different times for different days of week
-- ex - so have dayofweek:2:00,dayofweek:3:00 (and we parse out the day of week and number splitting out the strings)
-- hourly - to do more then once a day??
-- WHEN @ScheduleLookupType = 'hourly' THEN DATEADD(DAY, 1, @CurrentScheduleDate) -- FIX FIX FIX
-- EXEC dbo.JobsDynamicRescheduleFindNextTimeToScheduleJob @ReportName = 'TestReport1'
----------------------------------------------------------------------------------
ALTER PROCEDURE [dbo].[JobsDynamicRescheduleFindNextTimeToScheduleJob]
@ReportName VARCHAR(50)
AS
SET NOCOUNT ON
BEGIN TRY
-- left here for testing outside of SP
-- this will be passed from SP
--DECLARE @ReportName AS VARCHAR(50)
--SET @ReportName = 'TESTREport'
-- this sets the first day of the week to Monday (we need it set to a value to do calcluations for weekdays, I set it to 1 for monday and 7 for sunday)
-- this is due to server settings could have somethign else so forcing it here
SET DATEFIRST 1
DECLARE @CurrentScheduleDate AS DATE -- find the current date for the job that just ran
DECLARE @CurrentScheduleDayNumberOfWeek AS SMALLINT -- this pulls the number of the day of week 1=monday, 2=tuesdday
DECLARE @ScheduleLookupType AS VARCHAR(20) -- this is the type of schedule to do calculations on
DECLARE @TimeOfDayToScheduleJob AS VARCHAR(20) -- look this up, its the time to schedule the job
DECLARE @SpecialScheduleValue AS VARCHAR(8000) -- this is special value to lookup (only needed if non standard one)
DECLARE @NewScheduleDateONLY AS DATETIME -- to hold just the date of the schedule before combinng with time
DECLARE @NewScheduleDateTime AS DATETIME -- to hold the new schedule date and time, actual value to insert into queue
-- pull the current schedule date/time from the queue table
SELECT @CurrentScheduleDate = NextRunDateTime
FROM dbo.GenericReportingQueue (NOLOCK)
WHERE IsGenerated IS NULL
AND ReportName = @ReportName
-- to override for testing
--SET @CurrentScheduleDate = '5/20/2016'
SET @CurrentScheduleDayNumberOfWeek = DATEPART(WEEKDAY, @CurrentScheduleDate)
-- pull these values from lookup table
SELECT @ScheduleLookupType = dbo.fn_GetValueLookupTableValue(@ReportName, 'RescheduleJobDynamic_ScheduleLookupType'),
@TimeOfDayToScheduleJob = dbo.fn_GetValueLookupTableValue(@ReportName, 'RescheduleJobDynamic_TimeOfDayToScheduleJob'),
@SpecialScheduleValue = dbo.fn_GetValueLookupTableValue(@ReportName, 'RescheduleJobDynamic_SpecialScheduleValue')
/*
-- reset for testing
SET @ScheduleLookupType = 'specialdays' -- weekly, weekdays, monthly, specialdays
SET @TimeOfDayToScheduleJob = '8:00'
SET @SpecialScheduleValue = '5,6'
*/
-- calculations to get the date to schedule the job next time based off logic
SELECT @NewScheduleDateONLY = CASE
WHEN @ScheduleLookupType = 'daily' THEN DATEADD(DAY, 1, @CurrentScheduleDate)
WHEN @ScheduleLookupType = 'weekly' THEN DATEADD(DAY, 7, @CurrentScheduleDate)
WHEN @ScheduleLookupType = 'monthly' THEN DATEADD(MONTH, 1, @CurrentScheduleDate)
WHEN @ScheduleLookupType = 'yearly' THEN DATEADD(YEAR, 1, @CurrentScheduleDate)
-- only run on weekdays and skip weekends
WHEN @ScheduleLookupType = 'weekdays' THEN
CASE
WHEN @CurrentScheduleDayNumberOfWeek IN (1, 2, 3, 4) THEN DATEADD(DAY, 1, @CurrentScheduleDate)
WHEN @CurrentScheduleDayNumberOfWeek = 5 THEN DATEADD(DAY, 3, @CurrentScheduleDate)
END -- end case for day of week
-- only run on weekends and skip weekdays
WHEN @ScheduleLookupType = 'weekends' THEN
CASE
WHEN @CurrentScheduleDayNumberOfWeek = 6 THEN DATEADD(DAY, 1, @CurrentScheduleDate)
WHEN @CurrentScheduleDayNumberOfWeek = 7 THEN DATEADD(DAY, 6, @CurrentScheduleDate)
END -- end case for weekends only
WHEN @ScheduleLookupType = 'specialdays' THEN
-- for this we need to determine the current day, and the next day we want to run on, then add that many days
-- if next day is not till the following week we just find the first day in the list
-- Take taht number and do dateadd to it
DATEADD(DAY,
-- this does the select to determine what number to add based off current day and next day list
(SELECT ISNULL(
-- if this one I want to take today value and subtract from next value found
-- then add that number to todays date to give me the next schedule date
(SELECT TOP 1 StringValue - @CurrentScheduleDayNumberOfWeek
FROM dbo.fn_ParseText2Table(@SpecialScheduleValue, ',')
WHERE StringValue > @CurrentScheduleDayNumberOfWeek
ORDER BY StringValue)
,
-- if none found above I need to go to the next weeks first value
-- I need to take 7 - todays number (to get the rest of the week) then add the next number for the next week to it
(SELECT TOP 1 (7 - @CurrentScheduleDayNumberOfWeek) + StringValue
FROM dbo.fn_ParseText2Table(@SpecialScheduleValue, ',')
ORDER BY StringValue)
)-- end is null
) -- end select
, @CurrentScheduleDate) -- end dateadd for speical days
END -- outer case
SET @NewScheduleDateTime = @NewScheduleDateONLY + ' ' + @TimeOfDayToScheduleJob
-- for testing
--SELECT @ScheduleLookupType AS ReportLookupType, @TimeOfDayToScheduleJob AS TimeOfDayToSchedule, @SpecialScheduleValue AS SpecialValuesForCalc, @NewScheduleDateTime AS NewDateTimeToRun,
--@CurrentScheduleDate AS CurrentDateSchedule, @CurrentScheduleDayNumberOfWeek AS CurrentNumberDayOfWeek, @NewScheduleDateONLY AS NewScheduleDateOnly
-- &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
-- now update and insert the new schedule date/time into the table
-- update existing record
UPDATE dbo.GenericReportingQueue
SET IsGenerated = 1,
DateReportRun = GETDATE(),
LastUpdateDate = GETDATE()
WHERE ISGenerated IS NULL
AND ReportName = @ReportName
-- insert new record with new date
INSERT INTO dbo.GenericReportingQueue (
ReportName, NextRunDateTime, CreatorID, CreateDate
)
SELECT @ReportName, @NewScheduleDateTime, 1, GETDATE()
END TRY
BEGIN CATCH
RETURN
END CATCH
【讨论】：