【正文】 最后，一旦構(gòu)建了一個(gè)可接受的原型，開發(fā)者和用戶將決定最后的原型和數(shù)據(jù)庫(kù)是否能交付使用。這一步通常是數(shù)據(jù)庫(kù)開發(fā)過(guò)程中最長(zhǎng)的一步，因?yàn)樗掷m(xù)數(shù)據(jù)庫(kù)及相關(guān)應(yīng)用的整個(gè)生命周期，每次數(shù)據(jù)庫(kù)的發(fā)展都可看作一個(gè)簡(jiǎn)略的數(shù)據(jù)庫(kù)開發(fā)過(guò)程，其中會(huì)出現(xiàn)概念數(shù)據(jù)建模、邏輯和物理數(shù)據(jù)庫(kù)設(shè)計(jì)以及數(shù)據(jù)庫(kù)實(shí)現(xiàn)以處理提出的變化。 邏輯數(shù)據(jù)庫(kù)設(shè)計(jì)的最后一步是根據(jù)為生成結(jié)構(gòu)良好的數(shù)據(jù)規(guī)格說(shuō)明而確定的規(guī)則，將組合的、協(xié)商后的數(shù)據(jù)規(guī)格說(shuō)明轉(zhuǎn)換成基本的或原子的元素。首先，它在項(xiàng)目開始和規(guī)劃階段建立 一張圖。即使在自底向上的情況下，建立企業(yè)數(shù)據(jù)模型也是必須的，以便理解現(xiàn)有的數(shù)據(jù)庫(kù)是否可以提供所需的數(shù)據(jù)，否則，新的數(shù)據(jù)庫(kù)、數(shù)據(jù)實(shí)體和屬性都應(yīng)該加到當(dāng)前的組織數(shù)據(jù)資源中去。請(qǐng)注意，系統(tǒng)開發(fā)生命周期的階段和數(shù)據(jù)庫(kù)開發(fā)步驟之間不存在一一對(duì)應(yīng)的關(guān)系，概念數(shù)據(jù)建模發(fā)生在兩個(gè)系統(tǒng)開發(fā)生命周期階段之間。然后像設(shè)計(jì)信息系統(tǒng)的每個(gè)計(jì)算機(jī)程序（包括程序的輸入和輸出格式）那樣，對(duì)數(shù)據(jù)庫(kù)支持的事務(wù)、報(bào)表、顯示和查詢進(jìn)行詳細(xì)的檢查。最后一步是利用現(xiàn)存的信息源（遺留應(yīng)用中的文件和數(shù)據(jù)庫(kù)以及現(xiàn)在需要的新數(shù)據(jù)）加載數(shù)據(jù)。一般來(lái)說(shuō)，當(dāng)信息系統(tǒng)的問(wèn)題被確定時(shí)，僅僅粗略地嘗試概念數(shù)據(jù)建模。s database, these rules from the relational database theory and the process known as standardization, . This step is the result of management of these data have not cited any database management system for a plete description of the database map. Logical database design pleted, we began to identify in detail the logic of the puter program and maintenance, the report contents of the database for inquiries. 4. Physical database design and definition Physical database design and definition phase decisions puter 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 and decision support statements. The objective of this stage is to design an effective and safe management of all dataprocessing database, the physical database design to closely integrate the information systems of other physical aspects of the design, including procedures, puter hardware, operating systems and data munications works. 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 processing languages (such as SQL), or the process of the nonexclusive language programming in order to produce a statement of the fixed format, the result will be displayed, and may also include c harts. In achieving stage, but also the pletion of all the database files, training users for information 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 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. 6. Database maintenance 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. When a procedure or failure of the puter 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 can 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. Information System developed by