Kaleidoscope: a cooperative menu-guided query interface (SQL version)

Kaleidoscope´s approach is presented in the context of seeking improvement in the usability of interactive structured query language (SQL) interfaces. The system´s cooperation is summarized as proposing valid query constituents step-by-step and providing lexical and semantic feedback immediately to users. To implement this intraquery guidance, the context-free grammar (CFG) is extended to capture the constraints useful for intraquery guidance, and the knowledge useful for pruning nonsensical queries and providing semantic feedback is articulated. For the SQL interface, this knowledge includes a strong domain concept, functional dependency, and integrity constraint rules, which can be acquired once in the database design step. The same types of knowledge are useful both for postquery cooperation and intraquery guidance. As SQL is supported bv virtually all database management system (DBMS) vendors, the approach presents a practical solution for casual database access