Preference SQL

Preference SQL is a declarative extension of the SQL query language by preferences behaving as soft constraints. Preference SQL has been developed at the Chair for Databases and Information Systems at the University of Augsburg, Germany. Salient benefits of Preference SQL are: Context-adaptive and location-based preference modeling; Personalized query results, avoiding annoying empty results and reducing the flooding effect; Best-matches query model combined with Top-k interface .