The Research On Applying XML To Data Exchange System

With the developing of enterprise cooperation, many information systems need to access heterogeneous databases. The heterogeneity embody the different database structure, type and data type mismatch.. The extensible Markup becomes the standard of data describing format for its strong ability to describe the data and insignificance of infrastructure.This text firstly analyzes the dominance of XML to describe data, then introduces the interrelated technology. DTD and Schema define the data type and data legality. XSL prescribes the data deplay. DOM and SAX provide the interface for accessing XML. Comparing the database to XML, there are some similitude and relation in a certain extent. With the scope using the XML extending in reality, many databases enhance the ability for supporting XML.The XML-enabled database is a relational database that has inteface for XML. It can store document in database using relational schema.The next discuss the mapping rules between database and XML, the mapping based on Object-Relation is flexible but intricate. The mapping based on table is easily realized but can be used in simple situation. We can use two methods to get document. They are Template-Based Query and SQL-Based Query Language.At last, based on an actual example, the system accesses two databases using XML document. It defines the mapping relation between the resource database and the XML document, and makes the accessing result as DOM object tree. Before generate the regular document, it must search the mapping file. After deepen data model matching, the available document is gained. Programing on Oracle flat directly, we use the interface - the component XML SQL Utility for XML accessing Oracle database. Then transfer the data to aim database and realize the data exchange between the heterogeneous databases.During the data exchanging, XML support general data describe format, used for data mapping, and give data accessing interface.