Automatic generation of SQL queries for hierarchical XML schemas

The Extensible Markup Language (XML) was initially developed for document management, but it is becoming increasingly used for storing and exchanging all kinds of data on the Internet. One use of XML is for extracting information from relational databases and converting the information into a hierarchical XML document format. This makes it possible to extract data from databases into XML documents for use on the Internet [15]. XML documents are hierarchically structured, whereas most database models are graph-structured. In general, it is possible to create different hierarchical views of a relational database [16]. In the EER2XML Designer tool, users are allowed to specify various hierarchical document structures from a database schema. Several algorithms are developed for generating customized hierarchical views from an EER schema diagram, creating XML schemas and instance documents from hierarchical views.; In the process of developing algorithms within the “EER2XML Designer” for automating XML schema document design and extraction, it is necessary to create an SQL query corresponding to each XML-Schema document. The SQL query and hierarchy information are used to generate XML instance documents. This thesis presents algorithms to create SQL queries dynamically from a hierarchy structure that is generated from the ER Graph Database schema. The algorithm uses information from the data structures that describe both Hierarchy and EER schema.; The thesis also describes advantages of using EER to XML Schema approach and provides examples to explain these algorithms. We also briefly illustrate the features of EER2XML designer and the techniques developed in implementing algorithms in EER2XML designer.