A design of middleware components for the connection between XML and RDB

XML offers the opportunity to create richer documents than HTML can produce by introducing appropriate tags. The hottest application area of XML is messaging. Messaging is the exchange of messages between organizations or between application systems within an organization. For messaging by XML, you want to store XML messages, and you need a database that is tuned for data storage, such as a relational or object-oriented database, as well as middleware to transfer data between the database and XML messages. Component-based technology is a trend towards resolving the e-commerce challenge at both system and application levels. Instead of delivering a system containing any conceivable feature, component-based systems consists of a lightweight kernel to which new features can be added in the form of components. The basic capabilities of component-based systems should include the plug and play features at various granularities, interoperability across networks, portability on different hardware and software platforms, coexistence with legacy applications, mobility in various networking environments such as Internet, Intranet, and Extranet, and ability of self-managing data resources. In this paper, we draw out a set of middleware components to transfer data between the relational database and XML messages. For design of these middleware components, we use CBD (Component Based Development)