Structured Data To The Research And Implementation Of Xml Semi-structured Data

The technologies on WWW are the fastest developed technologies on Internet. XML (Extended Markup Language) is the most widely used format for marking up web content. Most of the business data is stored in relational database management systems. There were many formats for storing data in the past, but with the entry of relational database management systems, a standard format for data storage has emerged. An XML file is a plain text file that can easily be sent across network and can easily be transformed from one vocabulary to another. Data serialized in XML format provides flexibility to transmit and exchange data. Therefore, it is important to explore different ways to convert the database file into an XML file.This paper firstly introduce some knowledge about database theory and XML,then two conversion algorithms, called NeT and CoT, to translate relational Schemas to XML Schemas are presented.NeT derives a nested structured XML Schema from a flat relational Schema by repeatedly applying the nest operator so that the resulting XML Schema becomes hierarchical, and CoT takes a relational Schema as input, where multiple tables are interconnected through inclusion dependencies and generates an equivalent XML Schema as output. After analyzing the two algorithms ,a new algorithm based NeT and Cot is introduced.The algorithm—DTX divides an XML document hierarchical structure into four different topologies-single sub-element(element,sub-element),mutiple sub-elements(element, mutiple sub-element),group(element,group of sub-elements),and referral element.The view of the database is mappped into four topological XML documents according to their data semantics constraints.In the end ,Based on the algorithms DTX,a model is given.We can use it to convert a choosing view of a realtional databse into XML document.