"The inadequacies of traditional database query languages are often a limit to the utilization of databases by non expert users. Fourth generation languages (see     ), although non procedural, do not seem friendly enough for the casual user; in the interaction, the user must be able to model the information content of the database, and to employ a textual language. Moreover, the user's visual ability while interacting with the database is limited and the objects of interest are rarely displayed directly: rather, they are represented by formatted text, thereby not giving the user any iconic or spatial clues to help the querying process. "
[Show abstract][Hide abstract] ABSTRACT: A system to query databases using diagrams as a standard user
interface is proposed. The system, called Query by Diagram* (QBD*),
makes use of a conceptual data model, a query language on this model,
and a graphical user interface. The conceptual model is the
entity-relationship model. The query language, whose expressive power
allows recursive queries, supports visual interaction. The main
characteristics of the interface are ease of use and the availability of
a rich set of primitives for schema selection and query formulation. The
expressive power of QBD* and G<sup>+</sup>, which are the only languages
allowing recursive queries to be expressed graphically are
[Show abstract][Hide abstract] ABSTRACT: The need of a friendly man-machine interaction is becomingcrucial for a large variety of applications, in particular, thoserequiring frequent extraction of information from the database.Experience suggests that traditional query languages are notfriendly enough for the casual user: she/he is requested toformulate queries in a textual language, without any iconic orspatial clues to help the querying process. A new generation oflanguages (visual languages) has been recently investigated,...
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