Research Of Bi-directional Transformation Between XML Data And Relational Data With Semantic Constraints

With the development of Internet, Information sharing and Data exchanging become more available. Although XML is being used in cross-platform and heterogeneous data integration, it lacks of store and management mechanism. Nowadays, traditional relational database is still one of main storage methods and it has excellent store and management mechanism, but it cannot transport easily on the Internet. The implementation of the conversion between XML data and relational data will use the advantage of these technologies well.This thesis proposes the means of conversion between XML and relational data; in addition, this thesis also offer improvement of two conversion algorithms and offer a conversion method to translate relational data to XML in order to implement bi-directional conversion and maintain semantic constrains. This thesis mainly contains several parts as follows:First of all, the methods of conversion between XML and relational data are introduced; these algorithms' advantage and disadvantage are discussed for the conception and construction of this thesis.Secondly, the research on methods of conversion between XML and relational data: base on the research mentioned above, the improvement of two conversion algorithms are developed to ensure effective exchanging and to maintain the semantic as well. In the model mapping, this thesis also improves the method of bit-vector encoding; in the structure mapping, CPI can keep semantics effectively. However, CPI is based on DTD technology, XML Schema is better than DTD in the semantic constraints after comparison. Therefore, this thesis proposes CPI method base on XML Schema, so that it can ensure effective exchanging and to maintain semantics effectively. Third, the research on methods of conversion between relational data and XML:this thesis defines a conversion algorithm in order to offer the ability to convert effectively and maintain semantics effectively.Finally, this thesis designs and implements a prototype system. The discussions of the implementations and results of test work certificate the algorithm provided by this thesis is correct and effective.