VOODOO: A Visual Object-Oriented Database Language for ODMG OQL

This paper presents a simple and eeective visual language to express ODMG OQL queries. The language is expressive enough to allow most types of query nesting, aggregation, universal and existential quantiications, group-by, and sorting, and at the same time is uniform and very simple to learn and use. Our visual language is strongly typed in the sense that queries constructed in our system are always type-correct. In addition, there is suucient type information displayed by the system that guides every stage of the query construction. The main diierence between our language and other related visual query languages is that we use only one generic visual construct, called a template, instead of inventing a new one for each OQL syntactic feature.