The Research And Application Of Nested Tables Modeling In Data Source Aggregation

Web has stored extremely rich data resources, which brings more and more demand for data integration which end-users can use to develop value-added Internet applications to meet their individual needs. This application is a kind of new Internet data integration application, dominated by end-users, gathering data resource from multiple data resources in a short time.The purpose of the research of Internet Situational Applications is that how to make end-users can develop Situational Applications by themselves making Internet data resources get effectively used.The thesis focuses on how to enhance usability of development of Internet Situational Applications. The thesis presented a method of mapping XML documents to nested tables and realized the mapping from xml schema to the head of nested tables and the mapping from xml data to the body of nested tables.A kind of data structure used to store mapping information including merge information and content information of cells was designed which effectively reduce the complexity of converting XML document to nested tables and the algorithms of converting XML documents with complex structure to intermediate data structure also was present. Being its simpleness and intuitive in describing xml document, the nested tables is suited to be used as basic data structure to development of Internet Situational Applications.A kind of novel programming model of visual Situational Applications based on nested tables was present. In this programming model, a set of visual data operations were defined, then the business logic of Situational Applications can be expressed as a finite sequence of data operations. End-users can get the results that meet their individual needs by demonstrating the process of operation data resources. The thesis gave the implementation mechanism of the operation sequence and the definition of the XML file with specific format which is the persistence-form of the operation sequence also was given. Being that using instant feedback technology of resources convergence, the results of the operations can be shown immediately and the data and the operation never be separated, so we can say that to some extent, the usability of development of Situational Applications improve. Finally, the prototype of design and implementation was present and the method present was validated by using an example.