The Research On Storing XML Document Into Relational Storage Based On The Mapping Method From XML Schema To Relational Model

In recent years, with the fast development of Internet, XML has become an important medium for data representation, particularly when that data is exchanged over or browsed on the Internet. How to effectively manage XML documents is a difficult problem. Database is currently the main way of data storage; it is natural for people to hope for the combination of XML documents with Database System. As Relational Database System is far more mature and steady than other Database Systems in the aspects of storage management, query optimization, parallel control and Transaction management and so on, it becomes the emphasis of research. A viable method is to use Relational Database System to store and operate XML data, to transform half structured data into structured data, to distill, synthesize, and analyze a variety of XML data by querying database. So it makes use of relaively mature Relational Database technology, In the other hand, W3C recommend XML Schema as the standard schema for XML document in May, 2001. XML Schema has the same semantics as XML, provides more built-in data types and supports the extending of data types. So XML Schema can almost satisfy relational model to describe its data, so people may think if it is possible to transform from one XML Schema to relational model, then the XML document validity by XML Schema can be easily added into the relational model that is transformed.Through above analysis, this paper emphasizes to research how to transform XML Schema into Relational Database model on the basis of introducing XML language with the related knowledge and XML storage technologies. Firstly, it simply analyzes the transformation of the primary components of the XML Schema and researches how to transform from the built-in data type to relational model. It discusses how to transform the simple type element: separately to atomic type, list type and union type element, each of them uses the differently transformed method. In this foundation, it further discusses the transformation technology of attribute element and researches the transformation method of complex type element content. Secondly, it has studied the transformation of secondary components. It emphasizes to discuss the transformation of model group element and analyzes the method of the sequence model group, the choice model group and the all model group in turn, In the transforming process, the target is guaranteed as far as possible the integrity of XML Schema information.