Research On Conceptual Modeling Of XML Documents-methods And Tool

In the last few years, XML has become a powerful and widely used logical data model. Many organizations start to store data in XML, and most database systems have begun to support the storage and management of XML.However, XML does not have a suitable mechanism for intuitively creating a conceptual model for the data. The conceptual modeling techniques for XML are still not adequately explored. Literature shows many efforts towards the development of formal and conceptual models for XML, although no commonly accepted model exists as yet.In this dissertation, we study a design methodology for XML schemas that is based upon well-understood conceptual modeling methodologies. We present EERX model, which is an evolution of the extended Entity Relationship model that copes with the peculiar features of XML, and a conceptual modeling approach that can describe XML document structures in a simple visual form, and has the capability to semi-automatically generate XML schema from such structures. The method can support the conceptual modeling of XML data. An approach for visualizing EERX by extending PowerDesigner is also presented. We discussed the approach and implementation mechanism for visualizing the EERX diagram.We begin with the basic theory of XML, analyze its semi-structured characteristic, then we mainly discussed the method and tool for XML conceptual modeling systematically. Besides, we give specific examples to apply our EERX model and visualize EERX diagram by PowerDesigner, and we disscuses transformation from EERX to XML Schema. There are six chapters in this dissertation:Chapter 1 introduces the relevant concepts of XML, and needs to model database applications in XML, the research background, and the main work of this paper.Chapter 2 describes concepts of XML Schema and the three design levels of xml modeling, then presents modeling nuances in XML.Chapter 3 discusses some formal and conceptual modeling techniques, gives out main methods and key technologies to implement our model and visualization tool.Chapter 4 mainly introduces the constructs and definition of the conceptual model for XML Schema-EERX, giving detailed explanation with examples about EERX constructs.Chapter 5 introduces how to extend PowerDesigner to represent our customized model-EERX, and design conceptual models for XML Schemas, and analyze the implementation of translating this conceptual model to XML Schema.Chapter 6 summarizes our research, discusses the characteristics and shortcomings of our EERX model and points need to improve in developing a tool to visualize our model, then describes the future work of XML conceptual modeling.To sum up, detailed research and analysis have been made in this paper on XML conceptual modeling. The EERX model and modeling techniques have a general and practical significance. It's applicable and helpful in modeling XML applications.