Reverse Engineering of Relational Database Schema to UML Model

For the evolution and maintenance of legacy systems, it is essential that they are reverse engineered. It is becoming important because in many Legacy systems, suitable documentation is not available which makes maintenance. The proposed approach extracts hidden information which is useful for maintaining a software. Application modeling and data modeling are essential for the development of the software and are used for designing application and database separately. Generally, in software systems application layer is the object-oriented programming language and database is the backend store. Modeling of these layers separately creates inconsistency. This paper proposes a technique to reverse engineer the database schema to UML model which will incorporate modeling of an object-oriented technology on top of purely relational database. Using this conversion of database schema to UML diagram, the gap between these layers is being bridged. It will provide the understanding of the legacy system in a better way. The database schema is converted into XMI format which can be imported in a UML modeling tool. The proposed approach converts the SQL database schema as well as more frequently used SELECT statements for the schema into UML model which is in the form of XMI. By importing the generated XMI file into MagicDraw, UML model is graphically represented.