1、(用外文寫) 外文出處： asp?ztid=467&page=1 錯誤！未找到索引項。 數據庫開發過程 基于信息工程的信息系統規劃是數據庫開發項目的一個來源。這些開發新數據庫的項目通常是為了滿足組織的戰略需求，例如改善客戶支持、提高產品和庫存管理或進行更精確的銷售預測。然而許多數據庫開發項目更多的是以自底向上的方式出現的，例如信息系統的用戶需要特定的信息來完成他們的工作，從而請求開始一個項目，又如其他信息系統的專家發現組織需要改進數據管理而開始新的項目。即使在自底向上的情況下，建立企業數據模型也是必須的，以便理解現有的數據庫是否可以提供所需的數據，否則，新的數據庫、數據實體和屬性都應該加到當前

2、的組織數據資源中去。 無論是戰略需求還是操作信息的需求，每個數據庫開發項目通常集中在一個數據庫上。一些數據庫項目僅僅集中在定義、設計和實現一個數據庫，以作為后續信息系統開發的基礎。然而在大多數情況下，數據庫及其相關信息處理功能是作為一個完整的信息系統開發項目的一部分而被開發的。一. 系統開發生命周期 指導管理信息系統開發項目的傳統過程是系統開發生命周期(sdlc)。系統開發生命周期是指一個組織中由數據庫設計人員和程序員組成的信息系統專家小組詳細說明、開發、維護和替換信息系統的全部步驟。這個過程比作瀑布是因為每一步都流到相鄰的下一步，即信息系統的規格說明是一塊一塊地開發出來的，每一塊的輸出是下一

3、塊的輸入。然而如圖所示，這些步驟并不是純線性的，每個步驟在時間上有所重疊（因此可以并行地管理步驟），而且當需要重新考慮先前的決策時，還可以回滾到前面某些步驟。（因而水可以在瀑布中倒流！）系統開發生命周期的每一階段都包括與數據庫開發相關的活動，所以，數據庫管理的問題遍布整個系統開發過程。請注意，系統開發生命周期的階段和數據庫開發步驟之間不存在一一對應的關系，概念數據建模發生在兩個系統開發生命周期階段之間。1.1 企業建模 數據庫開發過程從企業建模（系統開發生命周期中項目論證和選擇階段的一部分）開始，設定組織數據庫的范圍和一般內容。企業建模發生在信息系統規劃和其他活動期間，這些活動確定信息系統的哪

4、個部分需要改變和加強并概述出全部組織數據的范圍。在這一步中，檢查當前數據庫和信息系統，分析作為開發項目主體的業務領域的本質，用非常一般的術語描述每個信息系統在開發時所需要的數據。每個項目只有當它達到組織的預期目標時才可以進行下一步。1.2 概念數據建模 對一個已經開始的信息系統項目而言，概念數據建模階段分析信息系統的全部數據需求。它分為兩個階段。首先，它在項目開始和規劃階段建立一張圖。同時建立其他文檔來概述不考慮現存數據庫的情況下特定開發項目中所需的數據范圍。此時僅僅包括高層類別的數據（實體）和主要聯系。然后在系統開發生命周期的分析階段產生確定信息系統必須管理的全部組織數據的詳細數據模型，定義

5、所有數據屬性，列出全部數據類別，表示數據實體間所有的業務聯系，確定描述數據完整性的全部規則。在分析階段，還要檢查概念數據模型（在后面也稱作概念模式）與用來解釋目標信息系統其他方面的模型類別的一致性，例如處理步驟、處理數據的規則以及時間的時序。然而，即使是這樣詳細的概念數據模型也只是初步的，因為后續的信息系統生命周期中的活動在設計事務、報表、顯示和查詢時可能會發現遺漏的元素或錯誤。因此，經常說到的概念數據建模是以一種自頂向下的方式完成的，它由業務領域的一般理解所驅動，而不是由特定的信息處理活動所驅動。1.3 邏輯數據庫設計 邏輯數據庫設計從兩個角度進行數據庫開發。首先，將概念數據模型變換成基于關

6、系數據庫理論的標準表示方法關系。然后像設計信息系統的每個計算機程序（包括程序的輸入和輸出格式）那樣，對數據庫支持的事務、報表、顯示和查詢進行詳細的檢查。在這個所謂的自底向上的分析中，精確地驗證數據庫中需要維護的數據和在每個事務、報表等等中需要的那些數據的性質。 對于每個單獨的報表、事務等等的分析都要考慮一個特定的、有限制的但是完全的數據庫視圖。當報表、事務等被分析時有可能根據需要而改變概念數據模型。尤其在大型的項目中，不同的分析人員和系統開發者的團隊可以獨立地工作在不同的程序或程序集中，他們所有工作的細節直到邏輯設計階段才可能會顯示出來。在這種情況下，邏輯數據庫設計階段必須將原始的概念數據模型

7、和這些獨立的用戶視圖合并或集成到一個全面的設計中。在進行邏輯信息系統設計時也可以確定額外的信息處理需求，此時這些新的需求必須集成到前面確定的邏輯數據庫設計中。 邏輯數據庫設計的最后一步是根據為生成結構良好的數據規格說明而確定的規則，將組合的、協商后的數據規格說明轉換成基本的或原子的元素。對當今的大部分數據庫而言，這些規則來自關系數據庫理論和稱作規范化的過程。這一步的結果是產生管理這些數據的、不引用任何數據庫管理系統的完整的數據庫描述圖。在完成邏輯數據庫設計后，開始確定詳細的計算機程序的邏輯和維護、報告數據庫內容所需的查詢。1.4 物理數據庫設計和定義 物理數據庫設計和定義階段決定計算機存儲器（

8、通常是磁盤）中數據庫的組織，定義數據庫管理系統的物理結構，概述處理事務的程序，產生期望的管理信息和決策支持的報表。本階段的目標是設計能夠有效、安全地管理所有數據處理的數據庫，因此物理數據庫設計需緊密結合物理信息系統其他方面的設計，包括程序、計算機硬件、操作系統和數據通信網絡。1.5 數據庫實現 數據庫實現階段編寫、測試和安裝處理數據庫的程序。設計人員可以使用標準的編程語言（如cobol、c或visual basic）、專用的數據庫處理語言（如sql），或專用的非過程化語言來編程，以產生固定格式的報表、顯示結果，可能還包括圖表。在實現階段，還要完成所有的數據庫文檔，培訓用戶，為信息系統（和數據庫

9、）的用戶安裝程序。最后一步是利用現存的信息源（遺留應用中的文件和數據庫以及現在需要的新數據）加載數據。加載數據的第一步經常是將數據從現存的文件和數據庫中轉到一種中間的格式（如二進制或文本文件），然后再將這些中間數據加載到新的數據庫中。最后，運行數據庫以及相關的應用以供實際的用戶維護和檢索數據。在運轉期間，定期備份數據庫，并當數據庫損壞或受到影響時恢復數據庫。數據庫開發過程- 1 -一. 系統開發生命周期- 1 -1.1 企業建模- 2 -1.2 概念數據建模- 2 -1.3 邏輯數據庫設計- 2 -1.4 物理數據庫設計和定義- 3 -1.5 數據庫實現- 3 -二. 信息系統開發的其他方法-

10、 4 -database development process- 6 - 數據庫在數據庫維護期間逐漸發展。在這一步，為了滿足變化的業務條件，為了改正數據庫設計的錯誤，或數據庫應用的處理速度而增加、刪除或改變數據庫的結構特征。當一個程序或計算機發生故障而使數據庫受到影響或損壞時也可能應該重建數據庫。這一步通常是數據庫開發過程中最長的一步，因為它持續數據庫及相關應用的整個生命周期，每次數據庫的發展都可看作一個簡略的數據庫開發過程，其中會出現概念數據建模、邏輯和物理數據庫設計以及數據庫實現以處理提出的變化。二. 信息系統開發的其他方法 系統開發生命周期法或其稍作變化的變體經常用于指導信息系統和數據

11、庫的開發。信息系統生命周期是一種方法學，它是高度結構化的方法，它包括許多檢查和權衡以確保每一步產生精確的結果，而且新的或替代的信息系統與它必須通信的或數據定義需要一致的現存系統保持一致。系統開發生命周期法經常由于產生一個工作系統需要很長的時間而受到批評，因為工作系統僅僅在整個過程結束時才產生。現在組織越來越多的使用快速應用開發法，它是一個包含分析、設計和實現步驟的快速重復的迭代過程，直到匯聚到用戶所需的系統為止。快速應用開發法在所需的數據庫已經存在、增強系統主要是為了檢索數據的應用中適用，而不適用于那些生成和修改數據庫的應用。 使用最廣泛的快速應用開發法之一是原型法。原型法是一個系統開發的迭代

12、過程，通過分析員和用戶的緊密配合，持續地修改系統而最終將所有需求轉換成一個工作系統。在此圖中我們包含了注釋，概略地描述了每個原型法階段的數據庫開發活動。一般來說，當信息系統的問題被確定時，僅僅粗略地嘗試概念數據建模。在開發最初的原型時，設計用戶想要的顯示和報表，同時理解任何新的數據庫需求并定義一個用語原型的數據庫。這通常是一個新的數據庫，它復制現存系統的一部分，還可能增加了一些新的內容。當需要新的內容時，這些內容通常來自外部數據源，如市場研究數據、一般的經濟指標或行業標準。 當產生原型新的版本時重復數據庫的實現和維護活動。通常僅進行最低限度的安全性和完整性控制，因為此時的重點是盡可能快地產生可

13、以使用的原型版本。而且文檔管理也延遲到項目的最后，在交付使用時才進行用戶培訓。最后，一旦構建了一個可接受的原型，開發者和用戶將決定最后的原型和數據庫是否能交付使用。如果系統（包括數據庫）效率很低，那么系統和數據庫將被重新編程和重新組織以達到期望的性能。隨著可視化編程工具（如visual basic、java、visual c+和第四代語言）越來越流行，利用可視化編程工具可以很方便地修改用戶與系統間的界面，原型法正成為可供選擇的系統開發方法。使用原型法改變用戶報表和顯示的內容和布局是相當容易的。在這個過程中，新的數據庫需求被確定，因此被發展中的應用使用的現存的數據庫應該進行修改。甚至有可能為一個

14、需要新的數據庫的系統使用原型法，在這種情況下，當系統需求在迭代的開發過程中不斷變化時需要獲取樣本數據以建造或重建數據庫原型。附件2：外文原文database development processbased on information engineering information systems planning database is a source of development projects. these new database development projects is usually in order to meet the strategic needs of org

15、anizations, such as improving customer support, improve product and inventory management, or a more accurate sales forecast. however, many more database development project is the bottom-up approach emerging, such as information system user needs specific information to complete their work, thus beg

16、inning a project request, and as other information systems experts found that organizations need to improve data management and begin new projects. bottom-up even in the circumstances, to set up an enterprise data model is also necessary to understand the existing database can provide the necessary

17、data, otherwise, the new database, data entities and attributes can be added to the current data resources to the organization.both the strategic needs or operational information needs of each database development projects normally concentrated in a database. some projects only concentrated in the d

18、atabase definition, design and implementation of a database, as a follow-up to the basis of the development of information systems. however, in most cases, the database and associated information processing function as a complete information systems development project was part of the development. o

19、ne. system development life cycleguide management information system development projects is the traditional process of system development life cycle (sdlc). system development life cycle is an organization of the database designers and programmers information system composed of the panel of experts

20、 detailed description, development, maintenance and replacement of the entire information system steps. this process is because waterfall than for every step into the adjacent the next step, that is, the information system is a specification developed by a piece of land, every piece of the output is

21、 under an input. however shown in the figure, these steps are not purely linear, each of the steps overlap in time (and thus can manage parallel steps), but when the need to reconsider previous decisions, but also to roll back some steps ahead. (and therefore water can be put back in the waterfall!)

22、 the system development life cycle including each stage and database development-related activities, therefore, the question of database management systems throughout the entire development process. in figure 5 we repeat of the system development life cycle stage of the seven, and outlines the commo

23、n database at each stage of development activities. please note that the systems development life cycle stages and database development steps exists between the relationship between the concept of modeling data in both systems development life cycle stages between.1.1 enterprise modeling database de

24、velopment process from the enterprise modeling (system development life cycle stage of the project feasibility studies, and to choose a part)organizations set the scope and general database content. enterprise modeling in information systems planning and other activities, these activities determine

25、which part of information systems need to change and strengthen the entire organization and outlines the scope of data. in this step, check the current database and information systems, development of the project as the main areas of the nature of the business, with a very general description of eac

26、h term in the development of information systems when needed data. each item only when it achieved the expected goals of organizations can be when the next step.1.2 conceptual data modeling one has already begun on the information system project, the concept of data modeling phase of the information

27、 systems needs of all the data. it is divided into two stages. first, it began the project in the planning stage. at the same time outlining the establishment of other documents to the existing database without considering the circumstances specific development projects in the scope of the required

28、data. this category only includes high-level data (entities), and main contact. then in the system development life-cycle analysis stage must have a management information system set the entire organization details of the data model definition of all data attributes, listing all data types that all

29、data inter-entity business linkages, defining description of the full data integrity rules. in the analysis phase, but also the concept of inspection data model (also called the concept behind the model) and the goal of information systems used to explain other aspects of the model of consistency ca

30、tegories, such as processing steps, rules and data processing time of timing. however, even if the concept is such detailed data model is only preliminary, because follow-up information system life cycle activities in the design of services, statements, display and inquiries may find that missing el

31、ement or mistakes. therefore, the concept of data often said that modeling is a top-down manner, its areas of operation from the general understanding of the driver, rather than the specific information processing activities by the driver. 1.3 logical database design logical database design from two

32、 perspectives database development. first, the concept of data model transform into relational database theory based on the criteria that means - between. then, as the design of information systems, every computer procedures (including procedures for the input and output format), database support se

33、rvices, statements, and inquiries revealed that a detailed examination. in this so-called bottom-up analysis, accurate verification of the need to maintain the database and the data in each affairs, statements and so on the needs of those in the nature of the data. for each separate statements, serv

34、ices, and so on the analysis must take into account a specific, limited but complete database view. when statements, services, and other analysis might be necessary to change the concept of data model. especially in large-scale projects, the different analytical systems development staff and the tea

35、m can work independently in different procedures or in a centralized, the details of their work until all the logic design stage may be displayed. in these circumstances, logic database design stage must be the original concept of data model and user view these independent or merged into a comprehen

36、sive design. in logic design information systems also identify additional information processing needs of these new demands at this time must be integrated into the logic of earlier identified in the database design.logical database design is based on the final step for the formation of good data sp

37、ecifications and determine the rules, the combination, the data after consultation specifications or converted into basic atomic element. most of todays database, these rules from the relational database theory and the process known as standardization, #. this step is the result of management of the

38、se data have not cited any database management system for a complete description of the database map. logical database design completed, we began to identify in detail the logic of the computer program and maintenance, the report contents of the database for inquiries. 1.4 physical database design a

39、nd definitionphysical database design and definition phase decisions computer memory (usually disk) database in the organization, definition of according to the library management system for physical structure, the procedures outlined processing services, produce the desired management information a

40、nd decision support statements. the objective of this stage is to design an effective and safe management of all data-processing database, the physical database design to closely integrate the information systems of other physical aspects of the design, including procedures, computer hardware, opera

41、ting systems and data communications networks. 1.5 database implementation the database prepared by the realization stage, testing and installation procedures for handling databases. designers can use the standard programming language (such as cobol, c or visual basic), the dedicated database proces

42、sing languages (such as sql), or the process of the non-exclusive language programming in order to produce a statement of the fixed format, the result will be displayed, and may also include charts. in achieving stage, but also the completion of all the database files, training users for information

43、 systems (database) user setup program. the final step is to use existing sources of information (documents legacy applications and databases and now needs new data) loading data. loading data is often the first step in data from existing files and databases to an intermediate format (such as binary

44、 or text files) and then to turn intermediate loading data to a new database. finally, running databases and related applications for the actual user maintenance and retrieval of data. in operation, the regular backup database and the database when damaged or affected resume database.1.6 database ma

45、intenance during the database in the progressive development of database maintenance. in this step, in order to meet changing business conditions, in order to correct the erroneous database design, database applications or processing speed increase, delete or change the structure of the database. wh

46、en a procedure or failure of the computer database affect or damage the database may also be reconstruction. this step usually is the longest in the database development process step, as it continued to databases and related applications throughout the life cycle, the development of each database ca

47、n be seen as a brief database development process and data modeling concepts arise, logical and physical database design and database to achieve dealing with the changes. two. information system developed by other means system development life cycle minor changes in law or its variant of the often u

48、sed to guide information systems and database development. information system is a life-cycle methodology, it is highly structured approach, which includes many checks and balances to ensure that every step of produce accurate results, and new or alternative information system and it must communicat

49、ions or data definitions consistent existing system needs consistency. system development life cycle because of the regular need to have a working system for a long time been criticized because only work in the system until the end of the whole process generated. more and more organizations now use

50、rapid application development method, it is a includes analysis, design and implementation of steps to repeat the rapid iterative process until convergence to users the system so far. rapid application development act required the database has been in existence, and enhance system is mainly to the a

51、pplication of data retrieval application, but not to those who generate and modify database applications. the most widely used method of rapid application development is one of the prototype. the prototype system is a method of iterative development process, analysts and users through close co-opera

52、tion, continuing to revise the system will eventually convert all the needs of a working system. in this diagram we contains notes, briefly describes each stage of the prototype of the database development activities. normally, when information systems problems were identified, tried only a rough concept of data modeling. in the development of the initial prototype, the design of the user wants to display and statements, and that any new database needs and define a term prototype database. this is usually a new database, copy the part