[00:00.00]Chapter 9 Database Management System
[00:03.07]第九章 数据库管理系统
[00:06.14]Dialogue 1
[00:07.82]句型1
[00:09.51]A:Hey ,Greg , Check out my new wallpaper!
[00:12.43]嘿，Greg，看一下我屏幕的新背景画面！
[00:15.36]I scanned a bunch of pictures from our trip to Hawaii last summer.
[00:18.60]我把去年夏天到夏威夷旅游的一堆照片扫了进去。
[00:21.84]B:I like it .But it must take up a lot of memory.
[00:24.35]不错嘛，可是一定占了不少的硬盘空间。
[00:26.85]A: It's not too bad , Besides I've got a 20 Gig hard drive.so I've got plenty of room
[00:30.55]还好，再说我的硬盘容量有20G，所以还有不少的空间。
[00:34.25]Dialogue 2
[00:35.66]句型2
[00:37.07]A:Something is wrong with my computer screen.
[00:39.63]我的电脑屏幕有点不对劲。
[00:42.19]Everything looks yellow.
[00:44.84]一切都变黄了。
[00:47.49]B:Try wiggling the cable that attaches it to your computer.
[00:51.00]把连接电脑的那条线摇摇看。
[00:54.52]A: Hey , it worked!
[00:55.75]嘿，好了！
[00:56.97]B: Sometimes that happens when the cable gets old and the connection isn't as good.
[01:01.00]有时候电线老化，接触不良时就会这样。
[01:05.02]Dilogue 3
[01:07.03]句型3
[01:09.04]A:I keep getting so much spam in my e-mail.
[01:12.24]我不断收到大量的电子垃圾邮件。
[01:15.44]What can I do about it?
[01:16.76]有什么办法吗？
[01:18.08]B: If your account has filters, you can block certain senders,or re-route mail with certain content to a different folder.
[01:25.62]如果你的帐号有过滤器，就可以挡掉一下，不然就把某些内容的邮件改投至另一个文件夹。
[01:33.15]A:I think my account does have filters, I'll have to check that out.
[01:36.67]我想我的帐号是有过滤器的，我来查查看。
[01:40.18]Dialogue 4
[01:41.86]句型4
[01:43.55]A: You're going to be gone for 3 weeks?
[01:45.87]你将离开三个星期是不是？
[01:48.20]B:That's right.
[01:49.52]是的。
[01:50.84]A:You'll have a lot of e-mail to catch up with when you get back.
[01:53.67]等你回来时一定有一大堆e-mail等着你。
[01:56.51]B:Actually, I'll have all my mail forwarded to a web-based account while I'm gone.
[02:00.62]其实，我不在的时候，我会将所有邮件都转发到网络基地账户内。
[02:04.73]That way, I can keep up with it anywhere I can get on the Internet.
[02:08.16]这样的话，不论人走到哪里，只要上得了网就可以随时读取了。
[02:11.58]passage Database Management System
[02:14.18]数据库管理系统
[02:16.78]professional Terms
[02:18.51]专业术语
[02:20.25]administrator n.
[02:22.12]管理人
[02:23.99]afford vt.
[02:25.40]有力
[02:26.81]appropriate a.
[02:28.45]适当的
[02:30.10]cabinet n.
[02:31.93]柜，箱
[02:33.76]comprehensive a.
[02:36.13]综合性的
[02:38.51]corporate a.
[02:40.25]集团的，公司的
[02:41.99]cross-referenced a.
[02:44.09]可相互参照的
[02:46.19]extract vt.
[02:48.24]提取
[02:50.29]folder n.
[02:52.03]文件夹
[02:53.77]item n.
[02:55.50]项目，物品
[02:57.24]order v.
[02:59.11]定购
[03:00.98]participate v.
[03:03.12]参与
[03:05.26]payment n.
[03:07.22]支付（的款项）
[03:09.18]picture vt.
[03:10.92]描写
[03:12.65]relevant a.
[03:14.57]相关的
[03:16.49]request n.
[03:18.27]请求
[03:20.05]sort vt.
[03:21.78]分类，排序，拣选
[03:23.52]specialist n.
[03:25.48]专家
[03:27.44]unpaid a.
[03:29.40]未付的
[03:31.36]A database is a large group of stored, integrated ( cross-referenced )data.
[03:34.87]一个数据库就是一大组存储起来的、集成的（可相互参照）的数据。
[03:38.38]usually organized in files that can be retrieved and manipulated to produce information.
[03:42.13]通常它们被组织在文件中，这些数据可以通过检索与操作变换，以产生信息。
[03:45.88]A database management system(DBMS) is a comprehensive software tool that allows users to create.
[03:51.41]一个数据库管理系统（DBMS）是一个综合性的软件工具，用户可以用来建立、
[03:56.93]maintain ,and manipulate the database to produce the relevant management information.
[04:00.90]维护和操纵数据库，以便产生有关的管理信息。
[04:04.87]By integrated we mean that the file records are logically related to one another so that all data on a topic can be retrieved by simple requests
[04:11.77]通过集成（我们所说的集成是指文件记录逻辑上的彼此关联起来），从而使得关于某个题目的全部数据，可以通过简单的请求加以检索。
[04:18.66]The database management systems software represents the interface between the user and the computer's operating system and database.
[04:25.25]数据库管理系统相当于用户、计算机操作系统和数据库之间的接口。
[04:31.83]Picture a typical corporate office with a desk , chairs ,telephone and a row of file cabinents along the wall.
[04:37.17]现在来描绘一个典型的公司办公室，室内有桌子、椅子、电话及靠墙的一排文件柜。
[04:42.51]A wide variety of business data is stored in these cabinets.
[04:45.17]在文件柜中，存有品种繁多的各类商业数据。
[04:47.82]If the files have been carefully organized and maintained then any piece of data that needs to be retrieved can quickly be located and removed.
[04:54.07]如果文件已经进行了仔细发组织与保管，那么任何一条数据，可以很快地找到并取出。
[05:00.33]However ,if the data has not been properly filed, some time and effort will be expended to find it.
[05:05.08]但是如果数据没有经过任何合适的存档，要找到该条数据所花费的时间和精力就会加大。
[05:09.84]And ,regardless of how carefully the files have been organized and maintained, you will always need to retrieve related pieces of data.
[05:15.27]而且无论文件是经过了多么细心地组织与保管，总需要检索与该数据有关的部分。
[05:20.71]For example ,suppose you need to review the customer files for all invoices for payments due in excess of $2,500 and prepare a simple report.
[05:28.11]举例说，假定你需要检查超过2，5000美元的全部到期应付款发货票的顾客文件，并需要准备出一份报告。
[05:35.52]notes
[05:36.56]注意事项
[05:37.61]How would you accomplish this task?
[05:39.29]你该如何完成这项任务？
[05:40.98]First ,you would probably go through the customer files in alphabetical order, foler by folder.
[05:44.91]第一，你可能要按字母顺序仔细检查顾客文件，一个文件夹接着一个文件夹去查。
[05:48.84]You would examine each invoice in the folders to determine if the amount is in excess of $2,500 and remove and copy each invoice that meets the criterion.
[05:57.16]你还要查看文件夹内的每个发货票，以便确定其数额是否超过2500美元，对于满足要求的每个发货票要取出并加以复印。
[06:05.48]You would then have to refill the copies you removed (and risk misfiling the
[06:12.43]When you had examined all the customer folders and copied all the appropriate invoices.
[06:15.90]然后你还必须把取出的部分重新归档（注意有归错档的危险），
[06:19.38]you would then review the copies and put together your report.
[06:22.30]当你检查了全部顾客文件夹并复印了全部需要复印的发货票，
[06:25.23]Imagine how much time this would take.
[06:27.33]可以设想一下，做这些工作要花去多少时间。
[06:29.43]If there are a lot of customers, you would need to spend hours if not days.
[06:32.67]如果有大量顾客时，即使无需花好几天，也需要花好几个小时吧。
[06:35.91]Now let's look at the situation in a different way.
[06:38.11]现在我们用另一种方式来研究这个问题。
[06:40.30]The environment is the same , except that ,instead of file cabinets.
[06:43.27]环境情况不变以，只是取代文件柜的是，
[06:46.23]you have a microcomputer or a terminal and DBMS software that has access to a customer database file as shown in the following .
[06:53.40]你有了一台微型机或一台终端，以及可以访问顾客数据库的DBMS软件，这个顾客数据库文件如下面所示。
[07:00.57]In this file a row of customer data is referred to as a record, and an individual piece of data within a record ,such as a name ,is referred to as a field.
[07:07.92]在文件中，每一排顾客数据称为一个记录，记录内的单独数据段（如姓名）则称为一个字段。
[07:15.28]To get the invoice data you need, you would do something like this.
[07:18.33]为了获得你所需的发货票数据，你总要做如下一些事情。
[07:21.39]Turn on the computer and the printer.
[07:23.81]启动计算机及打印机。
[07:26.22]start up the DBMS software
[07:28.24]启动DBMS软件。
[07:30.25]Give the command to open up the customer database file stored on your disk ,which is similar in concept to manually opening up the customer file in a filing cabinet.
[07:38.20]发出命令，以便“打开”存储在磁盘中的顾客数据库文件，从概念上讲“打开”既类似于用手打开文件柜中的顾客文件。
[07:46.16]Give the command to search all the records in the database file and display copies of the records that meet your criterion.
[07:51.92]发出命令，以便搜索查找数据库文件中的全部记录，并显示合乎要求的记录内容。
[07:57.68]that is the names of people with unpaid invoices greater than $2,500.
[08:01.46]（即，发货票总金额超过2500元未付款人的姓名）。
[08:05.25]If you were using dBASE IV , a popular microcomputer DBMS ,the command would look something like.
[08:11.05]如果你一直使用的是Dbase 1v（一种在微机上使用的著名的DBMS），则命令会是：
[08:16.85]If you were using SQL( Structured Query Language) the command would look like this.
[08:20.82]如果你一直使用SQL（结构化查询语言），则命令会是：
[08:24.79]In response to this command ,all the records in the file that have an invoice amount greater than $2,500 will be listed on the screen.
[08:31.60]作为这些命令的回答，在文件的全部记录中，凡是多于2500元的发货票，均将在屏幕上显示出来。
[08:38.40]The SQL command would also sort the listing into order by name.
[08:41.87]（SQL命令将挑选的发货票按姓名进行排序）。
[08:45.35]This whole procedure would take perhaps only five minutes or less.
[08:48.31]全部过程可能只需要5分钟，甚至更少。
[08:51.28]The DBMS is a software tool designed to manage a large number of integrated ,share electronic file cabinets.
[08:57.08]DBMS是一种软件工具，可用来管理许多综合的、共享的电子“文件柜”。
[09:02.88]You describe the type of data you wish to store.
[09:04.98]由你来描述要存储的数据类型，
[09:07.08]and the DBMS is responsible for creating the database file(s).
[09:10.50]而DBMS则负责建立数据库文件并提供一种易于使用的机制，
[09:13.93]and providing an easy to use mechanism for storing ,retrieving and manipulating the data.
[09:18.59]以便对数据存储、检索和操纵。
[09:23.25]In small businesses, databases may be both created and operated by the user.
[09:27.31]在小的企业中，数据库可能是由使用者本人建立和操作。
[09:31.38]In moderate to large size business with extensive computer systems.
[09:34.98]在拥有大量计算机系统的中型到大型企业，
[09:38.59]the corporate database is usually created by technical information speciallists, such as the database administrator.
[09:44.07]公司数据库通常是由信息技术专家（如数据库管理人员）所建立，
[09:49.56]but the database management system is acquired by the information systems department.
[09:53.44]但数据库管理系统却是由信息系统部门所获得。
[09:57.32]Users generate and extract data stored by the database management system.
[10:00.97]数据库管理系统所存储的数据是由使用者产生并提取。
[10:04.63]As with systems analysis and design.
[10:06.68]正如系统分析与设计一样。
[10:08.73]to design a database the organization must describe its informational needs to the designers and specify the type of data needed,
[10:14.90]为了设计一个数据库，企业组织必须向设计者描述其需要，并规定所需数据的类型。
[10:21.06]Users participate heavily in this process of defining what information needs to be stored in the database.
[10:26.09]在规定数据库需要存储哪些信息需要的过程中，使用者要参与大量的工作。
[10:31.12]Since the early 1980s, tremendous advances have been made in developing database management systems for microcomputers.
[10:37.10]自从二十世纪八十年代早期以来，在开发微型数据库管理系统方面，已经取得了惊人的进步。
[10:43.08]They are now easy enough for users to learn to operate without assistance and powerful enough to produce valuable management information.
[10:48.97]在无人帮助下，这种数据库管理系统极易被使用者学习使用，在产生有价值的管理信息方面，也极为有力。
[10:54.86]Regardless of whether you're in a large or a small business ,you cannot afford to do without the capabilities that a DBMS can provide.
[11:01.21]无论你是在一个大企业或小企业里，如果没有DBMS提供的作用，你将无能为力。
[11:07.56]Notes
[11:08.42]注意事项
[11:09.28]Regardless of whether you're in a larger or a small business ,you cannot afford to do without the capabilities that a DBMS can provide.
[11:14.77]无论你是在一个大企业或小企业里，如果没有DBMS提供的作用，你将无能为力。 |