Research And Application On Conversion And Retrieval Methods Of XML For Crop Pests Data

With the rapid development of computer network technology and database technology, especially vigorously advance of the agricultural information construction, Web Sharing of agricultural data resource has become a hot topic. Most agricultural data resources are stored in different forms in various types of database systems. Data exchanging between various data sources and Web Sharing is complicated and difficult due to the different data formats and heterogeneous versions of hardware platforms, operating systems and databases, which make them isolated. To solve this problem, we need to find a storage form as an intermediary to resolve the problem of data exchange and sharing problems between heterogeneous databases. XML (Extensible Markup Language) have flexible data format, the simple fundamentals of grammar and great language features, which make it the first choice of the intermediary transfer data.Most agricultural data resources are stored in the form of relational schema in a relational database because relational database has the perfect features and mature technology. Therefore, how to converte the agricultural data resource storaged in relational database to XML becomes an urgent need.At the same time, how to quickly and efficiently retrieve the information needed from the large-scale XML data becomes a key issue, and has also become an important research topic in the field of XML data.On the problems of Web share of agricultural data resource, we focus on the research on XML data conversion and retrieval methods to take crop pests data for the study. The main work is the research of crop pests data conversion methods and the design and development of crop pests data retrieval model based on XML. The main content of the thesis is as follows:1. The research of theories and methods of the conversion for crop pests data from relational database storage to XML document is proposed in this paper. This paper elaborately discusses the mapping techniques between relational databases and XML data.Through customizing conversion model, combined with the ADO.NET interface technology, this research establishs conversion model of crop pests data based on XML2. The research of theories and methods of retrieval for crop pests data based on XML is proposed in this paper. According to the characteristics of crop pests data descriped in XML, design an XML retrieval model based on two-dimensional table data set. Elaborate the retrieval model framework, and discuss the construction of two-dimensional data sets and retrieval process.Technologies of XSL style sheet conversion and Chinese word segmentation were also investigated.3. A crop pests data retrieval system based on XML is developed in Microsoft’s NET3.5framework,based on Microsoft Visual Studio2008development platform.We adopts ASP.NET、C#language programing、XSL、ADO.NET and Microsoft SQL Server to develop and implement a crop pest data retrieval system based on XML.This system can improve data retrieval efficient and accuracy to higher level.In this thesis, we put crop pests data as the research background, conducted in-depth study of XML data conversion and retrieval technology, the results of the research is to provide a way to solve the Web agricultural data resource sharing problem, and the research findings of the paper have the oretical research value and practical significance to the realization of agricultural information construction.