Research Of Transformation Between XML Data And Relational Data With Constraints

With the rapid development of Internet, information sharing and data exchange have been expanding sharply. Though XML has been comprehensively used in cross-platform and heterogeneous data integration, it lacks in perfect storage and management mechanism. Traditional relational database and vast amounts of XML data storage and management are faced with enormous challenges. The realization of the conversion between XML data and relational data will adequately exert the advantages of them.This thesis analyzes XML data's semi-structured feature and relational data's functional dependency and standardization theory. Comparing DTD to XML schema, we choose DTD as the document model of XML. We analyze the functional dependency phenomena of XML which are semantically constrained, and then we standardized them. We put forward methods to eliminate functional dependency transfer and indirect functional dependency transfer. Through the analyses of and comparison to the four common used interfaces of XML, we select DOM as the interface for XML data conversion and we clarify its components and functions in great detail.This thesis analyzes the existing technology for XML data and relational data conversion, i.e., template-driven model and model-driven model, and it improves the model-driven model, that is, to generate mapping model and initialized relational database by using data conversion middleware, considering data model as mapping method and defining document structure through DTD. We design the computing method for the mutual transfer of XML documents (which are semantically constrained) and relational database. This computing method determines the single attribute, which will substitute the primary key column, of all attributes. The single attribute reveals functional dependency of DTD in relational database so that semantic constraints are kept. We explain and exemplify the computing method, and prove the correctness of the method through application.