Research And Application Of Conversion Between XML Which Is A Kind Of Semi-Structured Data And Structured DB

The development of Internet technology has made the World Wide Web (or simply Web) rapidly becomes the most tremendous and important information resource library of the globe. the most information on Web exists in the form of HTML (HyperText Markup Language) document.The information in HTML document is display-oriented, not semantic-oriented, it's not convenient for data exchange. With the rapidly increase of the information amount and the expanse of the application range, the request for data exchange increases correspondingly. In order to make up the lack of semantic in HTML and make data exchange convenient, the World Wide Web Consortium, W3C for short propose the XML (eXtensible Markup Language). Hence, some experts predict XML will be the most important technology. As XML has some merits such as flexibility (which can define the tag by the user's request), easiness for using, etc., it is becoming the main way of information display and tool for exchange on the Web. The Web pages, Websites and application developing tools based on XML will come forth largely.First, this paper introduces the semi-structured data and correlative XML technology, the elementary content and the characteristic of XML, expatiates the relationship between XML and database, the advantage of using XML and the essential for creating the convert machinery between relational database and XML database. By analyzing the present technologies of the conversion between XML and database, we find that the common shortcoming of them is converting the data in database into XML directly, not concerning on the design of the database, based on the research source of this task---Music Order System of Business Intelligence software project offered by U-Soft Co., Ltd. In the direction of database design, based on the database entity-relation model, we put forward our new converting approach, the conversion between DTD diagram and ER diagram and complete background realization algorithm of conversion between XML and relational database. Then we give a simple application example with the approach we presented. Finally we give a music-preconcerted system, in which we implement the data exchange between XML and relational database by using DOM and ASP.This paper mostly solves the following problems:1) Researching the present technologies of the conversion between XML and database, analyzing the disadvantage and the advantage of these technologies, pointing out the improved way of the conversion method, indicating that this commutative conversion is incompletely reversible.2) Accomplishing converting the ER model of database into the DTD model of xml and bringing forward its algorithm.3) Accomplishing converting the DTD model of xml into the ER model of database and bringing forward its algorithm.