1、Training target:In this part,our target is to train the speed of reading professional article and comprehension.We have made the flexible sentences strong black and marked the subject,predicate and object of them.Try to grasp the main idea of these sentences.主语、谓语、宾语Part A Theoretical study section
2、DatabaseSkill one Foundation of Database System1.Database System ApplicationDatabase System is now used in various aspects of society,such as government apparatus,universities,airlines,banking,telecommunication and manufacturing.In government apparatus,database can be used to know information resour
3、ces of human affairs and carders in various aspects as well.In banking,database can be used for customer information,accounts,loans,and banking transactions.In airlines,database can be used for reservations and schedule information.In universities,database can be used for student information,course
4、registrations and grades.In the management of economy,database can process at statistic data,analyze,and obtain a result so as to guide the enterprises to develop rapidly.Previously,very few people interacted directly with the database system.database n.数据库apparatus n.机关，机构account n.账户loan n.贷款trans
5、action n.处理reservation n.订票registration n.注册 statistic 统计Part A Theoretical study section DatabaseSkill one Foundation of Database SystemTill the late 1990s,the assessment to database for user increased with the development of Internet work.For example,when you access a network station and look thro
6、ugh the contents on it,in fact,you are accessing the data stored in database.When you access an on-line shopping website,information about your order for goods may be retrieved from a database.Database plays an import role in most enterprises today.2.Basic Database conceptions Data:Data are a collec
7、tion of facts made up of numbers,characters and symbols,stored on a computer in such a way that the computer can process it.Data are different from information in that they are formed of facts stored in machine-readable form.When the facts are processed by the computer into a form,which can be under
8、stood by people,the data becomes information.look through 浏览retrieve 取回，收回Part A Theoretical study section DatabaseSkill one Foundation of Database System Database:Database is a collection of related objects,including tables,forms,reports,queries,and scripts,created and organized by a database manag
9、ement system(DBMS).A database can contain information of almost any type,such as a list of magazine subscribers,personal data on the space shuttle astronauts,or a collection of graphical images and video clips.Database management system:Data management system is a software that controls the data in
10、a database,including overall organization,storage,retrieval,security,and data integrity.A DBMS can also format reports for printed output and can import and export data from other application using standard file formats.A data-manipulation language is usually provided to support database queries.Dat
11、abase model:Database model is the method used by a database management system(DBMS)to organize the structure of the database.The most common database model is the relational database.query n.查询script n.文稿subscriber n.订购者shuttle n.宇宙飞船integrity n.完整性data-manipulation 数据控制Part A Theoretical study sect
12、ion DatabaseSkill one Foundation of Database System Database server:It is any database application that follows the client/server architecture model,which divides the application into tow parts:a front-end running on the users workstation and back-end running on a server or host computer.The front-e
13、nd interacts with the user,collects and displays the data.The back-end performs all the computer-intensive tasks,including data analysis,storage,and manipulation.Relational Database:Relational database is a database model in which the data always appear from the point of view of the user to be a set
14、 of two-dimensional tables,with the data presented in rows and columns.The rows in a table represent records,which are collections of information about a specific topic,such as the entries in a doctors patient list.The columns represent fields,which are the items that make up a record,such as the na
15、me,address,city,state,and zip code in an address list puter-intensive 计算密集型two-dimensional adj.二维的Part A Theoretical study section DatabaseSkill one Foundation of Database Systemdatabase n.数据库 object n.对象model n.模型 symbol n.符号enterprise n.企业 query n.查询online n.在线 two-dimensional adj.二维的 DBMS(Databas
16、e Management System)数据库管理系统relational database 关系数据库Part A Theoretical study section DatabaseKey WordsSkill Two Introduction of SQLSeveral different languages can be used with relational databases,the most common is SQL.SQL is an abbreviation of structured query language,and pronounced either see-kw
17、ell or as separate letters.SQL is a standardized query language for requesting information from a database.SQLs simple commands make easy for you to design and manage the information in your database.SQL(structured query language）n.结构化查询语言Part A Theoretical study section DatabaseSkill Two Introducti
18、on of SQLFor example,the most common SQL commands are classified as DDL,DML and DCL language commands.Now talk about data manipulation language(DML)commands,which you can use to insert,update,delete,and retrieve information from the tables in a database.There are two keywords:“SELECT”and“FROM”in SQL
19、 languages.SQL Server use DDL,DML and DCL sentences to control its program.DDL（data define language）n.数据定义语言DCL(data control language)n.数据控制语言Part A Theoretical study section DatabasePassage TwoRelational Database and Structured Query Language The original version called SEQUEL(structured English qu
20、ery language)was designed by an IBM research center in 1974 and 1975.SQL was first introduced as a commercial database system in 1979 by Oracle Corporation.The American National Standards Institute(ANSI)and the International Standards Organization(ISO)define software standards,including standards fo
21、r the SQL language.SQL Server 2000 supports the Entry Level of SQL-92,the SQL standard published by ANSI and ISO in 1992.The dialect of SQL supported by Microsoft SQL Server is called Transact-SQL(T-SQL).ISO国际标准化组织 Part A Theoretical study section DatabasePassage TwoRelational Database and Structure
22、d Query Language T-SQL is the primary language used by Microsoft SQL Server applications.Historically,SQL has been the favorite query language for database management systems running on minicomputers and mainframes.Increasingly,however,SQL is being supported by PC database systems because it support
23、s distributed databases(databases that are spread out over several computer systems).This enables several users on a local-area network to access the same database simultaneously.distributed databases分布式数据库simultaneously adv.同时地Part A Theoretical study section DatabaseSkill Two Introduction of SQLAl
24、though there are different dialects of SQL,it is nevertheless the closest thing to a standard query language that currently exists.In 1986,ANSI approved a rudimentary version of SQL as the official standard,but most versions of SQL since then have included many extensions to the ANSI standard.In 199
25、1,ANSI updated the standard.The new standard is known as SAG SQL(SQL Access Group).SQL contains about 60 commands and is used to create,modify,query,and access data organized in tables.It can be used either as an interactive interface or as embedded commands in an application:interactive interface交互
26、界面embed v.嵌入Part A Theoretical study section DatabaseSkill Two Introduction of SQL1)Dynamic SQL statements are interactive,and they can be changed as needed.If you normally access SQL from a command-line environment,you are using dynamic SQL,which is slower than static SQL but much more flexible.2)S
27、tatic SQL statements are coded into application programs,and as a result,they do not change.This statements are usually processed by a precompiler before being bound into the application.SQL is such a popular standard today,every major client/server application supports it.Many database implement SQ
28、L queries behind the scenes,enabling communication with database servers in systems with client/server architecture.dynamic adj.动态的static adj.静态的precompiler n.预编译程序Part A Theoretical study section DatabaseSkill Two Introduction of SQLSQL 结构化查询语言结构化查询语言 ANSI 美国国家标准化组织美国国家标准化组织ISO 国际标准化组织国际标准化组织 DDL 数
29、据定义语言数据定义语言 DCL 数据控制语言数据控制语言 DML 数据操纵语言数据操纵语言data-manipulation 数据控制数据控制distributed databases 分布式数据库分布式数据库interactive interface 交互界面交互界面integrity n.完整性完整性 retrieve v.检索检索simultaneously adv.同时同时 embed v.嵌入嵌入dynamic adj.动态的动态的 static adj.静态的静态的precompiler n.预编译程序预编译程序 client/server n.客户客户/服务服务 Part A T
30、heoretical study section Database Key WordsFast Reading One Object-Relational Database A data base management system(DBMS)is a software program that is used to create databases.The program also allows users to update tables and records within the database.What is an object-relational database(ORD)or
31、 object-relational database management system(ORDBMS)?An ORD or ORDBMS is a relational database management system,which allows developers to integrate the database with their own custom data types and methods.It allows the user to define new custom data types,new functions,and operators that manipul
32、ate these new custom types.That is,ORD combines the features of both relational databases and object-oriented programming.This means that when developing these databases,you can increase your ability to sort through and locate files within these databases faster,you can filter them better by assigni
33、ng these data types to your files,you can also retrieve files that share the same characteristics.Part A Theoretical study section DatabaseFast Reading One Object-Relational Database However,in an object oriented database,information is represented in the form of objects as used in object-oriented p
34、rogramming.Some object-oriented databases are designed to work well with object-oriented programming languages such as Python,Java,C#,Visual Basic.NET,C+and Smalltalk.Others have their own programming languages.The term object-relational database is sometimes used to describe external software produ
35、cts.An object-relational DBMS allows software developers to apply their own types and methods into the DBMS.Part A Theoretical study section DatabaseFast Reading One Object-Relational Database There are many advantages of object-relational database.ExtensibilityObject-relational database capabilitie
36、s are extended with the addition of new data types,access methods and functions are founded in object-oriented programming.You can add string characters with alpha-numeric data types.The complex data types can combine characteristics of data types that already exist in your database.You can specify
37、data types by the text you wish to contain or by the amount of bytes used to create it.User-defined data types can be opaque or distinctive.You can also add user-defined virtual processorsPart A Theoretical study section DatabaseFast Reading One Object-Relational Database InheritanceUnlike relationa
38、l databases,object-relational databases allow the use of inheritance.Within inheritance,you can develop classes for your data types.These objects can inherit certain capabilities from the classes to be used in other functions of the database.These inherited properties could be something simple.Throu
39、gh inheritance,your data types will inherit these features of other data types.Polymorphism Polymorphism in object relational databases involves allowing one operator to have different meanings within the same database.You can connect your tables within your database by building relationships.This i
40、ncludes records that may all contain the same name but different information.Part A Theoretical study section DatabaseFast Reading One Object-Relational Database EncapsulationYou would use encapsulation with object-relational databases in the form of tables.For instance,you want Table one to include
41、 name,address,telephone number and email address for your contacts.Through encapsulating the contacts class,you combine all of this information into this one table.So that when you query the database for this information,you generate a report in the style of a form to include all of this information
42、.Database Management SystemsObject-relational databases can be used to build database management systems.You can connect them to company websites that allow your inventory records to updates.The object components used on your website can make these updates when the user places an order by clicking o
43、ne of the control buttons programmed to connect to these database managements systems.Part A Theoretical study section DatabaseFast Reading Two Network DatabaseNetwork database refers to a database that runs in a network.It implies that the database management system（DBMS）was designed with a client
44、or server architecture.A network database consists of a collection of records connected to one another through links.A record is similar to an entity in the E-R model in many respects.Each record is a collection of attributes,each of which contains only one data value.A link is an association betwee
45、n precisely two records.A network database holds addresses of other users in the network.In the network database,a single data element can point to multiple data elements and can itself be pointed to by other data elements.Part A Theoretical study section DatabaseFast Reading Two Network DatabaseThi
46、s network model(Pic 6-1)has an ability to handle more relationship types.Namely,it can handle the one-to-many and many-to-many relationships.In the network model,there is always the first in the table,and the last in the table.If you need to restructure the database and add indexes,the users can use
47、 the new logic to improve the application logic.If you add a field,you have to restructure the entire table.The network database model implements application logic and limits the flexibility in the data structure.Part A Theoretical study section DatabaseFast Reading Two Network DatabaseNetwork datab
48、ase is a kind of database management system in which each record type can have multiple owners,e.g.orders are owned by both customers and products.This contrasts with a hierarchical database or relational database,the former is one owner,and latter is no explicit owner.Network database can access yo
49、ur work from any computer on that network.But you cant access your work if the server goes down.Ease of data accessIn the network database,a relationship is a set.Each set comprises of two types of records.They are owner records and member records.An application in a network model can access an owne
50、r record and all the member records within a set.Part A Theoretical study section DatabaseFast Reading Two Network Database Data IntegrityIn the network database,no member can exist without an owner.Therefore,to ensure the integrity,a user must first define the owner record and then the member recor
