Conversion Algorithm Of XML-GL And Xquery Based On DTD

As the development of computer technology and network technology, the enterprises and individuals transferred more and more data by Internet, XML is becoming the standard of data format and data transfer, more and more data are stored and exchanged as the format of XML, a mass of XML documents appear in the application of network. As the broad application of XML technology, XML query technology research has been more and more attention-getting, since the appearance of the XML1.0, there is a variety of XML query language, The research of XML query language has now become a hot in the XML database research field.At present, the industrial circles and academic made a lot of XML query language, grammatical forms and query capabilities in various languages are different. Among the query language, XQuery is a more mature language, many large companies as well as research institutions are optimistic about XQuery, and to varying degrees, provides a standard XQuery support. XML graphical query language is also an important direction of technology development, One of the typical characteristics of graphical query language is producing user-friendly query interface, it reduce the difficulty of users' learning XML query language, and improve users' querying efficiency of XML document.This paper affords an effective conversion technology from XML graphical query language to XQuery query language, on the basis of the research for XQuery and XML graphical query language.This paper discusses the development of XQuery, studies the syntax and feature of Xquery, improves the construction of the graphical query language's data model, and affords the conversion algorithm and rules from XML graphical query language to XQuery query language,on the basis of the construction of the condition query tree.Under the support of the conversion algorithm,users can query data with user-friendly interface in more XML database platform. The main works and achievements of this article are:·Afford a new graphical query language conversion. Describe the basic idea of the conversion algorithms of graphical query language detailedly.afford the formal description of the algorithm and the conversion rules,and gives specific examples of the algorithm.·Afford a structure scheme of the condition tree, and give the concrete steps and rules for the structure of the condition tree.·Discuss the data model of graphical query Language, and put forward the predigestion of the graphical query language and the rules of conversion between the data models.·Discuss the complex query in the graphical query language.The work of the paper is significative. This paper implements the conversion of the graphical XML query language and the XQuery language, and can support users query the XML data under more database platform in a more convenient way, it enrichs the related theories of the XML data query technology.