Research And Design Of Data Exchange Model Based On XML For Heterogeneous Database

The more and more applications need to access various heterogeneous data sources which distribute in the different locations along with the rapid of development. It has become an urgent problem that how to achieve data sharing and visiting between heterogeneous databases. Data exchange is a technology which aims to achieve date-sharing, aiming at this point, this paper sets up a new model of heterogeneous databases for data exchange.At first, the research content and status on data exchange were analysed. It was difficult for heterogeneous data exchange to build an effective public data model to describe the relationships between databases. With the features of strong semantics and well extendibility, XML is satisfied with the expression of relational database structure and the variety of constraints. This paper discussed the schema mappings between XML and relational databases, and gave the XML mapping rules between each other.In the process of heterogeneous databases for data exchange, the heterogeneous data model exist the various conflicts about structure and semantics. The rules library for the exchange of heterogeneous data was built to eliminate these conflicts in the paper, and a friendly interface was built in order to get rules making more flexible between human and machine.When large object datas were read from the source databases, they will formed binary data files. The binary data files can not directly put into XML documents, and were firstly coded for text-based format and then stored in XML text.Lastly, this paper presents a new data exchange model based on XML which hide the details of rules making. Through simulating a concrete example in the .NET platform, the result approved that the new model has the good features of universality and extendibility on data exchange between heterogenious databases.