The Research Of Mapping XML Data To Relational Data

With the swift and violent development of Internet, the data quantity grows unceasingly. The information resource On Web, usually exist by semi-structured data form, special xml data form. Different from structured data in-traditional database, the web data have no specific data model. They have the properties of self-description, dynamic changing and semi-structure.Facing the entire web environment, a lot of giant different structural database are composed of semi-structured data. In order to fully uses this kind of resources, we hoped straight use mature commercial RDBMS to manage the xml data uniform. Moreover, because xml by marks the text format depositing data. Therefore it is easier to become the standard of data exchange in the web.It is one inevitable tendency, xml data becomes the standard of data exchange, when data be transmitted between different platform or different structure database.In this case, the xml data transform to the structured data which saves based on the relational database, becomes the pop research. This paper thoroughly discusses mapping technology based on the XML documents definition type DTD, also propose a new transformation technology - extract the mapping layer by layer, this kind of technology is importance to maintaining the merit of XML documents stratification structure.This paper depict transformation technology in details from examples, and establishing the correct mapping relations between the xml data and the relational data, including mapping relations of structures and mapping relations of data. It is the problem that would be solved when the XML documents transform to relational data.