武汉理工大学数据库答案汇总.docx

1、武汉理工大学数据库答案汇总第一章：1.1What is the purpose of a database?数据库的目的The purpose of a database is to help people track(跟踪监测) of things.1.2What is the most commonly used type of database?最常见的数据库类型The most commonly used type of database is the relational database.1.3 Give an example of two related tables other

2、 than the example used in this book. Use the STUDENT and GRADE tables in Figure 1-3 as an example pattern(模式) for your tables. Name the tables and columns using the conventions in this book.给一个关联表的例子，参考1-3Answer:Query1：学生信息StudentNumberLastNameFirstNameEmailAddress1CookieSam1234OurU.edu2LaraMarcia12

3、45OurU.edu3HarrisLou2453OurU.edu4GreeneGrace2563OurU.edu5SmithAnna4345OurU.eduQuery2：宿舍信息StudentNumberRoomNumberRoomInformationRent115-1231000233-6331100344-4661200422-4541100554-45413001.4For the tables you created in Review Question 1.3, what are the primary keys of each table? Do you think that a

4、ny of these primary keys could be surrogate(代理) keys?每张表的主码？这些主码可以是代理码吗？Query1: StudentNumberQuery2: StudentNumber, RoomNumberYes, both.1.5 Explain how the two tables you provided in Review Question 1.3 are related. Which table contains the foreign key, and what is the foreign key?The primary key of

5、 Q1 were added to the Q2 with a primary key of StudentNumber to uniquely identify each row.In Q2 StudentNumber and RoomNumber each now serves as a foreign key.1.6 Show your two tables from Review Question 1.3 without the columns that represent the relationships. Explain how the value of your two tab

6、les is diminished(减少) without the relationships.在你的表中去掉代表关系的列，解释没有关系的表的value如何减少？1.7 Define the terms data and information. Explain how the two terms differ.定义术语data和information,解释它俩的不同。Answer: Data are recorded facts and numbers.We can define information as:Knowledge derived from data.Data presente

7、d in a meaningful context.Data processed by summing, ordering, averaging, grouping, comparing or other similar operations.1.8 Give an example of information that could be determined using the two tables you provided in your answer to Review Question 1.3.Anna Smith lives in 4-454 which the rent is 13

8、00.1.9 Give examples of a single-user database application and a multiuser database application other than the ones shown in Figure 1-5.举例子，单用户 和 多用户的数据库应用，除表1-5之外。single-user: Cloud Servicemulti-user: File Management System1.10 What problem can occur when a database is processed by more than one us

9、er? 当数据库被不止一个用户处理会导致什么问题？Answer: When more than one user employs a database application, these is always the chance that one users work may interfere with others.1.11 Give an example of a database application that has hundreds of users and a very large and complicated database. Use an example other

10、than one in Figure 1-5.举一个有成百上千个用户和一个庞大而复杂数据库的数据库应用，除表1-5以外。Answer: Selection lesson system选课系统1.12 What is the purpose of the largest databases at e-commerce companies such as Amazon ?像亚马逊这样的电商公司有着最大的数据库的目的是什么？Answer: The largest database are those that track customer browser behavior. (用来记录用户的浏览行为

11、)1.13 How do the e-commerce companies use the databases discussed in Review Question 1.12?电商公司如何使用数据库？Answer: E-commerce companies use Web activity databases to determine which items on a Web page are popular and successful and which are not.1.14 How do digital dashboard and data mining applications

12、 differ from transaction processing applications?数字仪表板和数据挖掘应用程序在事务处理应用上有何不同？Answer: Digital dashboard and other reporting systems assess past and current performance. Data mining applications predict future performance. 1.15 Explain why a small database is not necessarily simpler than a large one.解释

13、为什么一个小的数据库不一定比大的数据库简单？Answer: Supposed we have 2 company which are different in sales but have similar database. Though the difference in sale, both have the same kinds of data, about the same number of tables of data, about the same level of complexity in data relationships. Only the amount of data

14、 varies from one to the other. Thus, although a database for a small business may be small, it is not necessarily simple. (一句话，麻雀虽小五脏俱全)1.16 Explain the components in Figure 1-7.解释图1-7的成分要素A database system is defined to consist of five components:users, the database application, Structured Query La

15、nguage (SQL), the database management system (DBMS), and the database.a. Users employ a database application to keep track of things. They use forms to read, enter, and query data, and they produce reports to convey information.b. A database application is a set of one or more computer programs that

16、 serves as an intermediary between the user and the DBMS.c. Structured Query Language (SQL), an internationally recognized standard language that is understood by all commercial DBMS products, in database processing and the fact that database applications typically send SQL statements to the DBMS fo

17、r processing.d. The database management system (DBMS) is a computer program used to create, process, and administer the database.e. The database is a collection of related tables and other structures. 1.17 What are the functions of application programs?应用程序的功能是什么？Answer: Create and process forms Pro

18、cess user queries Create and process reports Execute application logic Control application1.18 What is Structured Query Language (SQL), and why is it important?Structured Query Language (SQL) is an internationally recognized standard language. Because it nearly can be understood by all commercial DB

19、MS products, in database processing, database applications typically send SQL statements to the DBMS for processing. (在数据库方法中，数据库应用向DBMS发送SQL语句)1.19 What does DBMS stand for?Database management system1.20 What are the functions of the DBMS? Create database、Create tables Create supporting structures

20、Read database data Modify (修改)(insert, update, or delete) database data Maintain database structures Enforce rules Control concurrency(并发控制) Provide security Perform backup and recovery (备份与恢复)1.21 Name three vendors of DBMS products.MySQL，Microsoft SQL Server，IBM1.22 Define the term database.(数据库一词

21、的定义)A database is a self-describing collection of integrated tables.1.23 Why is a database considered to be self-describing?A database is self-describing because it contains a description of itself. Thus, databases contain not only tables of user data, but also tables of data that describe that user

22、 data.1.24 What is metadata(元数据)? How does this term pertain(属于) to a database?databases contain not only tables of user data, but also tables of data that describe that user data. Such descriptive data is called metadata because it is data about data.(元数据是描述数据的数据)1.25 What advantage is there in sto

23、ring metadata in tables?You can examine(调查) metadata to determine if particular tables, columns, indexes, or other structures exist in a database.可以通过调查元数据得知某些特定的结构是否存在于数据库中1.26 List the components of a database other than user tables and metadata. 除了用户表和元数据以外的其他数据库组件。 Indexes Stored procedures Trig

24、gers Security data Backup/recovery data1.27 Is Microsoft Access a DBMS? Why or why not?No, Microsoft Access is not just a DBMS. Because it is a personal database system: a DBMS plus an application generator. Although Microsoft Access contains a DBMS engine that creates, processes, and administers th

25、e database, it also contains form, report, and query components that are the Microsoft Access application generator.(应用程序生成器)1.28-1.35了解就好，太偏太细，感觉不会考1.28 Describe the components shown in Figure 1-15.Components of a Microsoft Access Database SystemMicrosoft Access contains a DBMS engine that creates,

26、 processes, and administers the database, it also contains form, report, and query components that are the Microsoft Access application generator.1.29 What is the function of the application generator in Microsoft Access?The application generator consists of applications components that create and p

27、rocess forms, reports, and queries.1.30 What is the name of the DBMS engine within Microsoft Access? Why do we rarely hear about that engine?The current DBMS engine within Microsoft Access is called the Access Database Engine (ADE). ADE is a Microsoft Office specific version of Microsofts Joint Engi

28、ne Technology (JET or Jet) database engine. But you seldom hear about Jet because Microsoft does not sell Jet as a separate product.ADE是Jet引擎的一个版本，很少听说是因为Jet不是一个独立销售的产品1.31 Why does Microsoft Access hide important database technology?Because it is an effective strategy for beginners working on small

29、 databases1.32 Why would someone choose to replace the native Microsoft Access DBMS engine with SQL Server?You would do this if you wanted to process a large database or if you needed the advanced functions and features of Microsoft SQL Server. 1.33 Name the components of an enterprise-class databas

30、e system. 1.34 Name and describe the four categories of database applications that would use an enterprise-class database system. client/server applications：the application program is a client that connects to a database server. Client/server applications often are written in programming languages s

31、uch as VB.NET, C+, or Java.e-commerce applications：run on a Web serverreporting applications：publish the results of database queries on a corporate portal or other Web site.XML Web services applications：use a combination of the XML markup language and other standards to enable program-to-program communication.1.35 How do database applications read and write database data?All of these database applications get and put database data by sending SQL statements to the DBMS.1.35 How do database applications read and write database data?(数据库应用程序是如何读写数据库数据的？ PPT: First class