Conceptual Graph driven modeling and querying methods for RDMBS and XML databases

Relational Database Management Systems (RDBMS) are keeping the most of the market share even after almost 40 years from there first release. Nevertheless, the variety of data imposed the enrichment of traditional RDBMS with a large variety of systems known as NoSQL. Visual query systems (VQSs) are query systems for databases that use visual representation of the structure of databases and the representation of queries. VQSs are designed to improve the effectiveness of the human-computer communication offering a valuable graphical support for communication and further analysis. Conceptual Graphs are a particular system of logic based on the existential graphs of Ch.S. Peirce and the semantic networks of Artificial Intelligence. They express meaning in a logically precise form which is computer tractable and human readable. In this article we present relational database and semi-structured data modeling based on Conceptual Graphs. We also discuss a Conceptual Graphs based query designer for the relational data model and for XQuery. The expressive power of Conceptual Graphs gives a natural and intuitive tool for database structure design and database querying. The novelty of this work is an intuitive graphical web application which represents the XML data structure in form of Conceptual Graphs and gives the possibility of constructing queries also in form of Conceptual Graphs on the selected data structure.