Visionary: A Visual Query Language Based on the User Viewpoint Approach

Query languages for RDBMSs lack in intuitive understanding; this precludes inexperienced users from taking advantage of them. The adoption of a visual interface can simplify the query formulation process by enabling users to interact with a friendly environment. In this work we propose a visual query language based on a hybrid iconic-diagrammatic paradigm, used for both data and query representation. The external data model is called vision and comprises the visual primitives of concept represented by the combination of text and icon, and association represented by a name and a multiplicity for each possible orientation. The external query model is based on the definition of a user viewpoint, which is a perspective for accessing data defined dynamically by selecting a concept of primary interest for formulating each query.