Bipolar queries on fuzzy univalued and multivalued attributes in object databases

Flexible querying has been developed with the aim of proposing powerful and user-friendly ways of setting and solving queries. Within the context of flexible querying, the use of bipolar queries has deserved the attention of the research community as a way of distinguishing in queries negative and positive assessments of data. Bipolar queries have been specially studied in the framework of crisp relational databases. In this paper, we propose an approach to bipolar queries in fuzzy object databases. Through the use of a generalized inclusion concept, we deal with bipolar conditions on both fuzzy univalued and multivalued attributes. The consistence of the proposed approach with the bipolar queries rationale is also analyzed.