O Object Modeling of Rdbms Based Applications

As the development of industrial software applications become more complex, the benefits of developing a comprehensive “blueprint” enabling developers to visualize the scope of a project increase substantially. One of the key points in the development of most industrial applications is the design of the database. The object-oriented design paradigm enhances database modeling because the object model is expressive, concise, and relatively easy to use. On the other hand, the relational data model offers the advantages of a standard model, having a rigorous theoretical foundation, a mature technology, and the possibility to easily work with declarative languages. The complementary strengths of object and relational models makes it desirable to have them coexist in some form, achieving the best from both their paradigms (Li & Zhao, 2003; Musto et al., 2000 ). The Object Modeling of Relational Applications (OMAR) methodology uses object-oriented front end modeling and supports the generation of relational database schemes for the designed applications (Musto et al., 2000). It uses inference mechanisms exploiting the data structuring information and the dynamic models produced during the object-oriented modeling phases to infer an appropriate relational data schema and the associated manipulation mechanisms. Thus, a designer still benefits from the advantages offered by the object-oriented modeling paradigm, without loosing the above mentioned advantages offered by the relational data model. In this article, we show how we have used visual language technology to develop OMAR front-end CASE tools. A visual compiler generator, VLCC, has been used to model the syntax of UML diagrams and to generate a syntax driver editor and a compiler for them. Moreover, the inference mechanisms of OMAR have been embedded within VLCC by means of semantic routines. These are invoked upon the successful parsing of UML diagrams and produce an object/relational source code version of the application under development. We describe such a version of the code by using the PC++ language (Musto et al., 2000), a high level C++ providing abstract mechanisms to manage the communication with RDBMSs.