我正在进行一些数据转移,将数据从一个数据库移动到另一个数据库,并希望在不占用计算机太多内存的情况下完成。目前程序每分钟运行一次,但我想改变这种情况,以便每小时获取一次数据。最终,我想改变以下查询方式,不仅仅获取最新值,而是获取过去一小时的数据:
SELECT Data.[Date / Time],
DATA.[Hot Strip Mill Total],
Data.[Basic Oxygen Furnace Total],
Data.[Electro-Arc Furnace Total],
Data.[J-9 Shop Total],
Data.[Levy Maintence Building Total],
Data.[Ford Body Shop Total],
Data.[Ford Chiller Building Total],
Data.[Ford Dearborn W Plant Total],
Data.[Ford Dearborn E Plant Total],
Data.[Ford Dearborn Balcony Total],
Data.[Ford Final Assembly Total],
Data.[Ford Frame Plant Total],
Data.[Ford Dearborn N Plant Total],
Data.[Ford Tool and Die Total],
Data.[Ford Paint Plant Total],
Data.[Ford Glass Plant Total],
DATA.[Hot Strip Mill Rate],
Data.[Basic Oxygen Furnace Rate],
Data.[Electro-Arc Furnace Rate],
Data.[J-9 Shop Rate],
Data.[Levy Maintence Building Rate],
Data.[Ford Body Shop Rate],
Data.[Ford Chiller Building Rate],
Data.[Ford Dearborn W Plant Rate],
Data.[Ford Dearborn E Plant Rate],
Data.[Ford Dearborn Balcony Rate],
Data.[Ford Final Assembly Rate],
Data.[Ford Frame Plant Rate],
Data.[Ford Dearborn N Plant Rate],
Data.[Ford Tool and Die Rate],
Data.[Ford Paint Plant Rate],
Data.[Ford Glass Plant Rate]
FROM DATA
WHERE Format(Data.[Date / Time], 'mm/dd/yyyy hh:nn:ss') >=
(select Format(max(Data.[Date / Time]),'mm/dd/yyyy hh:nn:ss') from Data);
比如说,现在是上午10:51:00,我的程序正在运行,我希望它返回从09:51:00到现在的数据,同样的,在上午11:51:00时,返回从10:51:00到11:51:00之间的数据。我对Access不是很熟悉,但我在查询方面还是比较有能力的。这个问题让我感到困惑。有人能帮忙理解如何完成吗?谢谢。