The Research And Implement Of XML-based Data Exchange For Heterogeneous Database Systems

With the application of Campus networks widely, the technology of Campus networks are growing rapidly. Many universities have put "Digital Campus" on their agenda. One of the major problems is to integrate all kinds of data and resources and make them accessible through campus portal. To this end, a universal data interchange platform should be built to eliminate "isolated islands of information" caused by the campus network. This thesis discusses the main part of the universal data interchange platform - the data interchange of heterogeneous databases. Then it presents an XML based data exchange models. Finally, it discusses a practical prototype based on this model of data exchange of heterogeneous database systems.With the features of platform independency, easy extendibility, good interactivity and strong semantics, XML becomes the factual standard of data interchange. XML based data interchange model could easily implement the description of the isomeric databases and the interchange between the data sources, thereby it could solve the problem of the deficiency of the optimized federated query that exists in the current isomeric data integration and the problem of poor extendibility of the data integration of Web based isomeric database.First, the thesis discusses the related theory of data interchange of isomeric database, analyzes the traditional data interchange methods and problems, discusses XML technology related to the isomeric database data interchange and investigate the support of the typical database products to the XML. Then it analyzes the possibility of XML based data interchange from the aspects of schema binding of XML and relation database, data format binding of XML and relation database as well as the implementation of large object data interchange between isomeric database by using XML. Finally, it develops a XML based three-layer model for implementing data interchange of isomeric database and implements the data interchange between Oracle database and SQL Server 2000 database by using JDBC and DOM API through XML under the JAVA environment.In this paper the achievement of the thesis has the features of universality and extendibility because the basic theory of implementation is based on XML and the JAVA platform is used as the develop environment. In addition, the achievement is not only applicable to the university, but also to the other fields. It also could be used as the basis of the universal data interchange platform.