Myszkorowski, KrzysztofSuperson, Izabela2015-06-032015-06-032013Journal of Applied Computer Science., 2013 Vol.21 nr 1 s.89-1051507-03600000040295http://hdl.handle.net/11652/469The paper deals with flexible queries in relational databases. Conditions included in queries are modeled with the use of interval-valued fuzzy sets. Each value returned by a query is associated with a subinterval of [0,1] which expresses a membership degree. The bounds of membership intervals have been determined for different operations of relational algebra and different SQL operators.application/pdfenArtykuł