數(shù)據(jù)庫畢業(yè)設(shè)計(jì)外文翻譯

1、<p><b>　　附錄A </b></p><p>　?。?）Web數(shù)據(jù)庫概述</p><p>　　Internet技術(shù)的興起與發(fā)展，使社會(huì)大系統(tǒng)中出現(xiàn)了巨大的信息流和宏大的數(shù)據(jù)流，伴之而來的是Web技術(shù)的蓬勃發(fā)展，并且很快就占據(jù)了Internet技術(shù)的主流地位。而數(shù)據(jù)庫技術(shù)發(fā)展到今天已相對比較成熟，特別適合于對大量的數(shù)據(jù)進(jìn)行組織管理。由于Intern

2、et信息量的巨大，隨著Internet的進(jìn)一步發(fā)展，Web技術(shù)和數(shù)據(jù)庫技術(shù)的結(jié)合---Web數(shù)據(jù)庫技術(shù)便構(gòu)成了當(dāng)今Internet上最流行的新一代信息傳播技術(shù)，并且已深深地改變著網(wǎng)絡(luò)應(yīng)用的面貌。無論是網(wǎng)絡(luò)圖書館，網(wǎng)絡(luò)情報(bào)檢索系統(tǒng)，網(wǎng)絡(luò)信息出版，還是基于客戶機(jī)/服務(wù)器模式下的信息管理系統(tǒng)，都離不開Web數(shù)據(jù)庫技術(shù)。對于政府來講，開展電子政務(wù)已成為全球關(guān)注的熱點(diǎn)。20世紀(jì)90年代信息技術(shù)的迅猛發(fā)展，特別是互聯(lián)網(wǎng)技術(shù)的普及應(yīng)用，使電子政務(wù)的發(fā)

3、展成為當(dāng)代信息化的最重要的領(lǐng)域之一。通過Web數(shù)據(jù)庫技術(shù)，不僅把Web與數(shù)據(jù)庫的所有優(yōu)點(diǎn)集中在一起，而且充分利用了大量已有的數(shù)據(jù)庫信息資源，可以使用戶在Web瀏覽器上方便地檢索和瀏覽數(shù)據(jù)庫的內(nèi)容，所以，將Web技術(shù)與數(shù)據(jù)庫相結(jié)合，開發(fā)動(dòng)態(tài)的Web數(shù)據(jù)庫應(yīng)用，已是電子政務(wù)系統(tǒng)建設(shè)的一個(gè)必不可少的重要內(nèi)容。</p><p>　　（2）Web數(shù)據(jù)庫的產(chǎn)生</p><p>　　數(shù)據(jù)庫技術(shù)是人們長期

4、以來用來存儲(chǔ)各種各樣信息的手段。如今，Internet已經(jīng)遍布世界的各個(gè)角落，整個(gè)世界也被連成一體，因此Web數(shù)據(jù)庫技術(shù)也隨著Internet而滲透到地球的每個(gè)角落。</p><p>　　在Internet中，Web是發(fā)展最快的技術(shù)之一，但只具有信息發(fā)布功能的信息共享平臺(tái)的Web是靜態(tài)的，服務(wù)器響應(yīng)用戶請求，向用戶發(fā)送文件，用戶接收這個(gè)文件并把它顯示出來，這種工作方式不能實(shí)時(shí)交互動(dòng)態(tài)信息，客戶機(jī)和服務(wù)器之間的交流

5、是很有限的，滿足不了現(xiàn)代商務(wù)活動(dòng)的需求。后來隨著CGI技術(shù)的引入，特別是Java和JavaScreipt語言的引入，使得Web頁面可以方便地傳播動(dòng)態(tài)信息，與用戶進(jìn)行交互活動(dòng)。通過應(yīng)用Java和JavaScript語言，以及后來的VBscript，Perl等語言，可以很方便地設(shè)計(jì)具有動(dòng)畫，聲音，圖形圖像和種種特殊效果的Web頁面。這種交互式動(dòng)態(tài)Web頁面的實(shí)現(xiàn)需要大量的數(shù)據(jù)資源為基礎(chǔ)。為了對數(shù)據(jù)資源進(jìn)行高效的存取，數(shù)據(jù)庫系統(tǒng)自然而然就要進(jìn)

6、入Internet的舞臺(tái)，于是Web數(shù)據(jù)庫也就應(yīng)運(yùn)而生了。</p><p>　?。?）通過Web訪問數(shù)據(jù)庫的優(yōu)點(diǎn)</p><p>　　數(shù)據(jù)庫應(yīng)用的一個(gè)重要方面就是數(shù)據(jù)的訪問，但是許多數(shù)據(jù)庫系統(tǒng)目前提供的訪問方式，或是一個(gè)字符方式的查詢界面，或是通過編程方式實(shí)現(xiàn)，無論哪種方式都較難使用。近年來發(fā)展的一些RAD工具，如VB，Dephi，Powerbuider等可以方便地開發(fā)一些圖形界面的訪問數(shù)

7、據(jù)庫軟件，但是這樣的開發(fā)工具需要使用者具有編程技術(shù)，并且開發(fā)的程序不能跨平臺(tái)運(yùn)行。而且，用RAD工具開發(fā)的軟件，隨用戶需求的改變，可能需要增添新的功能或在界面上做一些改動(dòng)。如果開發(fā)的軟件使用范圍比較廣泛的話，那么軟件的更新將是一項(xiàng)很大的工作。而Internet技術(shù)的發(fā)展，使上述問題有了解決的辦法，如果建立了Web服務(wù)器，就可以通過Web服務(wù)器實(shí)現(xiàn)對數(shù)據(jù)庫的訪問，上面提到的問題也就可以解決了。</p><p>　　

8、與傳統(tǒng)方式相比，通過Web訪問數(shù)據(jù)庫的優(yōu)點(diǎn)在于：</p><p>　　1）借用現(xiàn)成的瀏覽器軟件，無需開發(fā)數(shù)據(jù)庫前端。如果能夠通過Web來訪問數(shù)據(jù)庫，就不需要開發(fā)客戶端的程序，使用的數(shù)據(jù)庫應(yīng)用都可以通過瀏覽器來實(shí)現(xiàn)，界面統(tǒng)一，也減少了培訓(xùn)費(fèi)用，能使廣大用戶很方便地訪問數(shù)據(jù)庫信息。</p><p>　　2）標(biāo)準(zhǔn)統(tǒng)一，開發(fā)過程簡單。HTML是Web信息的組織方式，是一種國際標(biāo)準(zhǔn)，開發(fā)者甚至只需學(xué)

9、習(xí)HTML語言，而使用者只需學(xué)習(xí)一種界面---瀏覽器界面。</p><p>　　3）交叉平臺(tái)支持。幾乎在各種操作系統(tǒng)上都有現(xiàn)成的瀏覽器可供使用，為一個(gè)Web服務(wù)器書寫的HTML文檔，可以被所有平臺(tái)的瀏覽器所瀏覽，實(shí)現(xiàn)了跨平臺(tái)操作。</p><p>　　（4）Web數(shù)據(jù)庫系統(tǒng)的基本模型</p><p>　　由于Web的易用性，實(shí)用性，它很快占據(jù)了主導(dǎo)地位，目前已經(jīng)成為

10、使用最為廣泛，最有前途，最有魅力的信息傳播技術(shù)。不過，Web服務(wù)只是提供了Internet上信息交互的平臺(tái)，要想實(shí)現(xiàn)真正的Internet，就要將人，企業(yè)，社會(huì)與Internet融為一體，這就要靠信息化應(yīng)用的實(shí)現(xiàn)。電子商務(wù)是以Web網(wǎng)絡(luò)技術(shù)和數(shù)據(jù)庫技術(shù)為支撐的，其中Web數(shù)據(jù)庫技術(shù)是電子商務(wù)的核心技術(shù)，支持電子商務(wù)已經(jīng)成為各大廠商競爭的焦點(diǎn)之一，Web數(shù)據(jù)庫的發(fā)展成為新的熱點(diǎn)和難題。Web數(shù)據(jù)庫就是能將數(shù)據(jù)庫技術(shù)與Web技術(shù)很好地融合在

11、一起，使數(shù)據(jù)庫系統(tǒng)成為Web的重要有機(jī)組成部分的數(shù)據(jù)庫，能夠?qū)崿F(xiàn)數(shù)據(jù)庫與網(wǎng)絡(luò)技術(shù)的無縫的有機(jī)結(jié)合。</p><p>　　早期的Internet數(shù)據(jù)庫系統(tǒng)采用的是兩層客戶機(jī)/服務(wù)器結(jié)構(gòu)。這種結(jié)構(gòu)在Internet應(yīng)用早期獲得了極大的發(fā)展。隨著Internet應(yīng)用的普及，由于Internet上信息資源的復(fù)雜性和不規(guī)范性，這種兩層結(jié)構(gòu)的數(shù)據(jù)庫系統(tǒng)在開發(fā)各種網(wǎng)上應(yīng)用時(shí)顯得力不從心，表現(xiàn)在無法管理各種網(wǎng)上的復(fù)雜的文檔型和多

12、媒體型數(shù)據(jù)資源，缺乏開放的標(biāo)準(zhǔn)，一般不能跨平臺(tái)運(yùn)行。為此就要求對數(shù)據(jù)庫作出一些適應(yīng)性調(diào)整，如增加數(shù)據(jù)庫的面向?qū)ο蟪煞忠栽黾犹幚矶喾N復(fù)雜數(shù)據(jù)類型的能力，增加各種中間件以擴(kuò)展基于Internet的應(yīng)用能力，通過應(yīng)用服務(wù)器解釋執(zhí)行各種HTML中嵌入腳本來解決Internet應(yīng)用中數(shù)據(jù)庫數(shù)據(jù)的顯示，維護(hù)，輸出以及到HTML的格式轉(zhuǎn)換等。此時(shí)，數(shù)據(jù)庫的基于Internet應(yīng)用的模式典型地表現(xiàn)為一種三層或四層的多層結(jié)構(gòu)，在這種多層結(jié)構(gòu)體系下，解決了

13、數(shù)據(jù)庫的Internet的應(yīng)用的方法問題，使得各種網(wǎng)上數(shù)據(jù)庫數(shù)據(jù)的發(fā)布，檢索，維護(hù)，數(shù)據(jù)管理等一般性應(yīng)用變得更加容易和簡單。</p><p>　　（5）Web數(shù)據(jù)庫的發(fā)展趨勢</p><p>　　最近幾年，數(shù)據(jù)庫市場飛速發(fā)展，電子商務(wù)成為各種企業(yè)發(fā)展的重點(diǎn)之一，甚至有人預(yù)言，電子商務(wù)極有可能建立起新型的虛擬商業(yè)，乃至虛擬工業(yè)。而電子商務(wù)是以數(shù)據(jù)庫技術(shù)和網(wǎng)絡(luò)技術(shù)為支撐的，其中數(shù)據(jù)庫技術(shù)是其核

14、心。更多的用戶已經(jīng)把數(shù)據(jù)庫的重要性放在十分重要的地位，其主要原因是用戶將把應(yīng)用軟件和應(yīng)用需求放在首位，而應(yīng)用軟件開發(fā)直接依賴于數(shù)據(jù)庫開發(fā)工具。另外，由于硬件隨著芯片技術(shù)的發(fā)展越來越缺乏特性，硬件指標(biāo)將變成次要的考慮因素。對行業(yè)性應(yīng)用來講，而今可能是首先選擇數(shù)據(jù)庫廠家再考慮硬件廠家了。正是用戶需求的這種變化給數(shù)據(jù)庫廠商提供了新的發(fā)展機(jī)會(huì)?？梢灶A(yù)言，在不久的將來，Web數(shù)據(jù)庫將成為數(shù)據(jù)庫領(lǐng)域研究的熱點(diǎn)技術(shù)。</p><p

15、><b>　　非結(jié)構(gòu)化數(shù)據(jù)庫</b></p><p>　　信息可以劃分為兩大類，一類信息能夠用數(shù)據(jù)或統(tǒng)一的結(jié)構(gòu)加以表示，稱之為結(jié)構(gòu)化數(shù)據(jù)，如數(shù)字，符號；而另一類信息無法用數(shù)字或統(tǒng)一的結(jié)構(gòu)表示，如文本，圖像，聲音，網(wǎng)頁等，稱之為非結(jié)構(gòu)化數(shù)據(jù)。結(jié)構(gòu)化數(shù)據(jù)屬于非結(jié)構(gòu)化數(shù)據(jù)，是非結(jié)構(gòu)化數(shù)據(jù)的特例。</p><p>　　隨著網(wǎng)絡(luò)技術(shù)的發(fā)展，特別是Internet和Intr

16、anet的飛速發(fā)展，使得非結(jié)構(gòu)化數(shù)據(jù)的數(shù)量日趨增大。這時(shí)，主要有于管理結(jié)構(gòu)化數(shù)據(jù)的關(guān)系數(shù)據(jù)庫的局限性暴露得越來越明顯。因而，數(shù)據(jù)庫技術(shù)相應(yīng)地進(jìn)入了“后關(guān)系數(shù)據(jù)庫時(shí)代”，進(jìn)入基于網(wǎng)絡(luò)應(yīng)用的非結(jié)構(gòu)化數(shù)據(jù)庫時(shí)代。所謂非結(jié)構(gòu)化數(shù)據(jù)庫，簡單地說，就是字段可變的數(shù)據(jù)庫。</p><p><b>　　2）異構(gòu)數(shù)據(jù)庫系統(tǒng)</b></p><p>　　相互關(guān)聯(lián)的數(shù)據(jù)庫可以很容易地被歸納

17、在一起，創(chuàng)建一個(gè)單一的虛擬數(shù)據(jù)庫，也叫做異構(gòu)數(shù)據(jù)庫系統(tǒng)。異構(gòu)數(shù)據(jù)庫系統(tǒng)是相關(guān)的多個(gè)數(shù)據(jù)庫系統(tǒng)的集合，可以實(shí)現(xiàn)數(shù)據(jù)的共享和透明訪問。每個(gè)數(shù)據(jù)庫系統(tǒng)在加入異構(gòu)數(shù)據(jù)庫系統(tǒng)之前本身就已存在，擁有自己的DBMS。 它的異構(gòu)性主要體現(xiàn)在以下幾個(gè)方面：計(jì)算機(jī)體系結(jié)構(gòu)的異構(gòu)；基礎(chǔ)操作系統(tǒng)的異構(gòu)；DBMS本身的異構(gòu)。它的目標(biāo)在于實(shí)現(xiàn)不同數(shù)據(jù)庫之間的數(shù)據(jù)之間的數(shù)據(jù)信息資源，硬件設(shè)備資源和人力資源的合并和共享。</p><p>　　

18、目前，異構(gòu)數(shù)據(jù)庫系統(tǒng)的集成以及建立在此基礎(chǔ)之上的數(shù)據(jù)倉庫，數(shù)據(jù)挖掘已經(jīng)成為網(wǎng)絡(luò)數(shù)據(jù)庫技術(shù)研究的重點(diǎn)之一。著名的國內(nèi)外數(shù)據(jù)庫廠商也將異構(gòu)數(shù)據(jù)庫系統(tǒng)作為競爭的焦點(diǎn)，研究如何將原來傳統(tǒng)的，可能分布于各地的多個(gè)關(guān)系數(shù)據(jù)庫集成起來，進(jìn)行改進(jìn)和發(fā)展，形成虛擬異構(gòu)數(shù)據(jù)庫系統(tǒng)和數(shù)據(jù)倉庫，更好地為企業(yè)信息化，電子商務(wù)服務(wù)。</p><p>　?。?）Web數(shù)據(jù)庫技術(shù)簡介</p><p>　　從技術(shù)發(fā)展的角度

19、來看，以前通過瀏覽器訪問數(shù)據(jù)庫的唯一渠道是CGI方式。隨后出現(xiàn)了SAPI和JDBC等技術(shù)方案，近來又流行ASP、JSP技術(shù)。下面對這些技術(shù)逐一進(jìn)行介紹。</p><p><b>　　1）CGI </b></p><p>　　CGI是Web服務(wù)器運(yùn)行時(shí)外部程序的規(guī)范，按照CGI編寫的程序可以擴(kuò)展服務(wù)器的功能，完成服務(wù)器本身不能完成的工作，外部程序執(zhí)行時(shí)可以生成HTML文

20、檔，并將文檔返回Web服務(wù)器。CGI應(yīng)用程序能夠與瀏覽器進(jìn)行交互作用，還可以通過數(shù)據(jù)庫的API與數(shù)據(jù)庫服務(wù)器等外部數(shù)據(jù)源進(jìn)行通信，如一個(gè)CGI程序可以從數(shù)據(jù)庫服務(wù)器中獲取數(shù)據(jù)，然后格式化為HTML，文檔后發(fā)送給瀏覽器，也可以將從瀏覽器獲得的數(shù)據(jù)放到數(shù)據(jù)庫中，幾乎所有的服務(wù)器軟件都支持CGI，開發(fā)者可以使用任何一種Web服務(wù)器內(nèi)置語言編寫CGI，其中包括流行的C，C++，VB和Dephi等。按照應(yīng)用環(huán)境的不同，CGI又可以分為標(biāo)準(zhǔn)CGI和

21、間接CGI。</p><p>　　CGI程序應(yīng)用是作為一個(gè)獨(dú)立的外部應(yīng)用來運(yùn)行的，與服務(wù)器上的其他程序競爭處理器資源，這將導(dǎo)致運(yùn)行速度減慢。而且，用CGI開發(fā)支持Web的應(yīng)用也是一個(gè)比較困難的數(shù)據(jù)庫過程中，連接狀態(tài)的管理也是很重要的。如果沒有狀態(tài)管理，那么瀏覽器的每一次請求，都需要一個(gè)連接的建立與釋放的過程，效率較低。CGI不提供狀態(tài)管理功能，另外，必須用某個(gè)特定數(shù)據(jù)庫服務(wù)器的專用SQL語言來手工編寫數(shù)據(jù)庫接口，

22、其移植性也不好。</p><p><b>　　2）JDBC</b></p><p>　　Java的推出，使Web有了活力和動(dòng)感。Internet用戶可以從Web服務(wù)器上下載Java小程序到本地瀏覽器上運(yùn)行。這些下載的小程序就像本地程序一樣，可獨(dú)立地訪問本地和其他服務(wù)器資源，而最初的Java語言并沒有數(shù)據(jù)庫訪問的功能，隨著應(yīng)用的深入，要求Java提供數(shù)據(jù)庫訪問功能的呼聲

23、越來越高。為了防止出現(xiàn)對Java在數(shù)據(jù)庫訪問方面各不相同的擴(kuò)展，JavaSoft公司制定了JDBC，作為Java語言的數(shù)據(jù)庫訪問API，JDBC是第一個(gè)標(biāo)準(zhǔn)的，支持Java數(shù)據(jù)庫的API，它使得Java程序與數(shù)據(jù)庫連接更為容易。JDBC在功能上與ODBC相同，給開發(fā)人員提供一個(gè)統(tǒng)一的數(shù)據(jù)庫訪問接口。目前，JDBC已經(jīng)得到了許多廠商的支持，包括Borland，Oracle和Sybase等公司。當(dāng)前流行的大多數(shù)數(shù)據(jù)庫系統(tǒng)都推出了自己的JDB

24、C驅(qū)動(dòng)程序。</p><p><b>　　3）JSP</b></p><p>　　JSP是Java Server Pages的簡稱,是Sun公司在Java語言基礎(chǔ)上開發(fā)的動(dòng)態(tài)網(wǎng)頁制作技術(shù)。JSP結(jié)合Servlet和JavaBean技術(shù),將網(wǎng)頁邏輯與網(wǎng)頁設(shè)計(jì)和顯示分離,支持可重用的基于組件的設(shè)計(jì),使基于Web應(yīng)用程序的開發(fā)變得迅速而簡單。JSP以良好的可移植性和平臺(tái)無關(guān)

25、性，強(qiáng)大的交互能力和數(shù)據(jù)處理能力，迅速風(fēng)靡全球，在Internet上幾乎處處都能看到它的身影，是動(dòng)態(tài)網(wǎng)頁語言未來發(fā)展的趨勢。</p><p>　　JSP技術(shù)為創(chuàng)建顯示動(dòng)態(tài)生成內(nèi)容的Web頁面提供了一個(gè)簡捷而快速的方法。JSP技術(shù)的設(shè)計(jì)目的是使得構(gòu)造基于Web的應(yīng)用程序更加容易和快捷，而這些應(yīng)用程序能夠與各種Web服務(wù)器，應(yīng)用服務(wù)器，瀏覽器和開發(fā)工具共同工作。 JSP規(guī)范是Web服務(wù)器、應(yīng)用服務(wù)器、交易系統(tǒng)、以及開

26、發(fā)工具供應(yīng)商間廣泛合作的結(jié)果。在傳統(tǒng)的網(wǎng)頁HTML文件(*htm,*.html)中加入Java程序片段(Scriptlet)和JSP標(biāo)記(tag)，就構(gòu)成了JSP網(wǎng)頁(*.jsp)。Web服務(wù)器在遇到訪問JSP網(wǎng)頁的請求時(shí)，首先執(zhí)行其中的程序片段，然后將執(zhí)行結(jié)果以HTML格式返回給客戶。程序片段可以操作數(shù)據(jù)庫、重新定向網(wǎng)頁以及發(fā)送 email 等等，這就是建立動(dòng)態(tài)網(wǎng)站所需要的功能。所有程序操作都在服務(wù)器端執(zhí)行，網(wǎng)絡(luò)上傳送給客戶端的僅是得

27、到的結(jié)果，對客戶瀏覽器的要求最低，可以實(shí)現(xiàn)無Plugin，無ActiveX，無Java Applet，甚至無Frame。</p><p>　　JSP技術(shù)是基于JAVA的開放性過程的產(chǎn)品，因此它能夠廣泛支持不同提供商提供的工具，WEB服務(wù)器和應(yīng)用程序的服務(wù)，這樣能夠使用戶選擇最佳的開發(fā)方法，選擇最適應(yīng)他們的應(yīng)用程序開發(fā)的工具包，同時(shí)，有效地保護(hù)用戶在代碼和人員培訓(xùn)上的投資，因而具有更廣闊的發(fā)展前景。</p&g

28、t;<p><b>　　4） ASP</b></p><p>　　ASP是微軟公司于1996年11月推出的Web應(yīng)用程序開發(fā)技術(shù)。在Microsoft的有關(guān)文檔中，ASP被描述為：一個(gè)服務(wù)器的腳本環(huán)境，可以生成和運(yùn)行動(dòng)態(tài)的。交互的，高性能的Web服務(wù)器應(yīng)用程序。ASP是目前公認(rèn)的建立Windows NT動(dòng)態(tài)站點(diǎn)最好的工具。它與ADO的充分結(jié)合，提供了強(qiáng)大的數(shù)據(jù)庫訪問功能，使之成

29、為進(jìn)行網(wǎng)上數(shù)據(jù)庫管理的重要手段。</p><p><b>　　附錄B </b></p><p>　　(1)Web database overview</p><p>　　The rise of Internet technology and development, social systems and the emergence of a

30、huge flow of information ambitious data flow, accompanied by the flourish of the Web technologies, and soon occupy the mainstream of Internet technology. Today database technologies are properly mature, and particularly

31、suited to the large number of organizations’ data management. Because of the tremendous volume of available information, with the further development of the Internet and Web technology and data</p><p>　　(2)W

32、eb database produce</p><p>　　The database technology is the tool that is used to store a variety of information. Today, the Internet has been found in all the corners of the world, the whole world has been i

33、ntegrated, and therefore Web database technology and the Internet infiltrate every corner of the planet. </p><p>　　In the Internet, Web technology grow fast, however only the dissemination functions of infor

34、mation sharing platform Web is static, server response to the request of users, documents sent to users, users receive this document and include the demonstration that such work can not be real-time dynamic information i

35、n the world, communication between client and server is very limited, can not meet the needs of modern business activities. With the subsequent introduction of CGI technology, particularly</p><p>　　(3)The ad

36、vantage of the database through Web visitation </p><p>　　Database application data is an important aspect of the visit, but many database systems currently available visit, or a character mode enquiries inte

37、rface, or through programming realization, either way it is used. In recent years a number of RAD development tools such as VB, Dephi, Powerbuider can conveniently visit database interface development of a number of grap

38、hics software, but such development needs of the users of programming tools technology and the development of procedures can not b</p><p>　　Compared with the traditional way, the advantages of Web visitation

39、 database: </p><p>　　1) loan available browser software, without the development of database front-end. If the visit to the database through the Web, it does not need to develop customer-procedures, the us

40、e of database applications can be achieved through the browser, unified interface, and reduce training costs, enable users conveniently access databases of information. </p><p>　　2) uniform standards, the

41、development process simple. HTML is Web information organization, is an international standard, developers can even learn HTML language, and users only need to learn a language interface --- browser interface. </p&g

42、t;<p>　　3) cross-platform support. In almost every operating system, the browser has made available to the HTML file .The written Web service device, the browser can be all the browsing platform, achieving cross-p

43、latform operation.</p><p>　　(4)Web database system basic models </p><p>　　As the Web user-friendly nature, practicality, it will occupy a dominant position, has become the most widely used, most

44、 promising, most charm of the information and communication technologies. However, Web service only provides Internet information platform in the world, the Internet is real, we must be people, enterprises, social integr

45、ation and the Internet, which relies on the application of information technology to achieve. Network technology and e-commerce Web database technology is suppo</p><p>　　The early introduction of the two-tie

46、r system of Internet database was client / server architecture. This structure was a great early in the Internet application development. With the popularity of Internet applications, as a result of Internet information

47、resources and the complexity of non-normative, this two-tier structure of the database system in the development of Internet applications seem unable, not performance in the management of complex web-based and multimedia

48、-based data file resour</p><p>　　(5)Web database development trends </p><p>　　In recent years, the rapid development of the database market, e-commerce has become one of the focal points of busi

49、ness development, and even some people predicted that e-commerce will most likely establish a new type of virtual business, and even virtual industry. E-commerce and database technology and network technology is supporte

50、d, which is its core database technology. More users on the importance of the database have been very important position, mainly because users will use application </p><p>　　1) Unstructured database</p>

51、;<p>　　Information can be classified into two categories, data or information used to be that a unified structure, known as structured data, such as figures, and other symbols. Figures or information that could no

52、t be unified structure, such as text, graphics, voice, web, call unstructured data. Structured data are unstructured data, the data is unstructured exception.</p><p>　　2) Heterogeneous unit database system &

53、lt;/p><p>　　Interrelated databases can easily be grouped together to create a single virtual database, also known as the heterogeneous unit database system. Heterogeneous unit database system is a database syst

54、em related to the assembly, to achieve data sharing and transparency visit. Each database system in the heterogeneous unit before the database system itself already exists, its own DBMS. Heterogeneous unit of its main ex

55、pression in the following areas: computer architecture heterogeneous unit; the het</p><p>　　The heterogeneous unit database system integration and the establishment of this foundation in the data warehouse,

56、data network database technology research excavation has become one of the focal points. Renowned manufacturers and the database will also heterogeneous unit database system as the focus of competition, how will the trad

57、itional research may be distributed in various parts of the relational database integration together for the improvement and development of a virtual Heterogeneous u</p><p>　　(6)Web database technology profi

58、les </p><p>　　From a technical development standpoint, previously adopted browsers visit database is the only channel for CGI. Subsequently, the SAPI and JDBC technology programmes, and recent popular ASP 、J

59、SP technology.</p><p><b>　　1) CGI</b></p><p>　　CGI is Web service devices operating procedures, external norms, prepared in accordance with the CGI procedures to expand server functi

60、onality, complete server itself unable to complete the work, external procedures can be generated HTML files, and files return Web service devices. CGI applications for interaction with the browser, etc. and also through

61、 the database, such as external data sources database server communications, such as a CGI process can obtain data from the database server, and </p><p>　　CGI applications as an independent external applicat

62、ion to the operation with other procedures competition processor server resources would lead to operate at a slower pace. Moreover, the use of CGI Web application development support is a more difficult process of the da

63、tabase, linking state management is very important. Without state management, then every browser request, require the establishment of a link with the release process less efficient. CGI does not provide state management

64、 functio</p><p><b>　　2) JDBC</b></p><p>　　Discuss the introduction of a vibrant and dynamic Web. Internet users can download Java from Web service objects to the small local browser,

65、 operating procedures. These procedures like downloading small local procedures, can independently visit local servers and other resources, and the initial database programming language did not visit functional, with app

66、lications in depth, providing a database for Java visit function has been getting higher and higher. To prevent the emergence of Java in the</p><p><b>　　3) JSP </b></p><p>　　JSP Java

67、 Server Pages is short Sun is the Java language development on the basis of dynamic web technology. Servlet and JSP with JavaBean technology, Logic and the website design and website shows separation, and support for reu

68、sable component-based design, Web-based application development becomes quick and simple. JSP to good portability and platform independent, powerful interactive capabilities, and data processing capability quickly swept

69、the world. on the Internet almost everywhere can see</p><p>　　JSP technology for the creation of dynamically generated content showed the Web page provides a simple and rapid method. JSP is designed to make

70、Web-based structural applications easier and faster. These applications can with a variety of Web server, application server, browser and development tools work together. JSP standard Web servers, application servers, tr

71、ansaction system and the development tool vendors extensive cooperation between the results. In traditional web HTML document (*htm. ht</p><p>　　JSP technology is based on Java open process products so it ca

72、n support the widely different providers with the tools, Web servers and application services, This enables the user to choose the best method of developing and select the most responsive to their application development

73、 tool kits, effective protection of the user code, and staff training on the investment, so they have an even broader prospects for development. </p><p><b>　　4) ASP</b></p><p>　　ASP

74、is Microsoft Corporation in November 1996 launched Web application development technology. Microsoft in the relevant files, ASP is described as: a server script environment, and can generate dynamic operation. The world,

75、 high-performance Web service device applications. ASP is a Windows dynamic site recognized the best tool. It is fully integrated with ado to provide a powerful database visitation function to become a major online datab