An Interface to Databases for Flexible Query Answering: A Fuzzy-Set Approach

This paper addresses a class of fuzzy queries with imprecise qualification. The imprecise qualification may contain a vague/imprecise expression, a linguistic term, or/and linguistic modifiers of the types (very) and (fairly). Single-attribute imprecise qualifications are studied in great length. A flexible α-cut technique is proposed for finding, approximate answers for simple imprecise qualifications, and also for formulating an integrated structure to deal with multiple (very) and multiple (fairly) for answering composite qualifications. The issues on negation and complex queries are briefly discussed. The proposed α-cut approach is adopted in the design of a front-end objected-oriented intelligent interface to access a relational database via a general-purpose relational DBMS.