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.