Top-k query of relational database based on CP-net

CP-net is a simple and intuitive graphical preference representation tool that can be used to describe the qualitative preference relationships implied in relatively tight, intuitive, structured conditional preference information. Full-featured qualitative decision-making with multiple dependencies between attributes in complete cases. Top-k queries are designed to retrieve the top k results that meet user requirements, thereby improving search efficiency. Aiming at implement Top-k queries with relational databases that have CP-net preferences. First, CP-net is induced into multiple tables for representation and storage, Then, the traditional Pareto composition is extended into the model so as to maintain a strict partial order relationship between preferences. Finally, based on “Lattice” theory, the Top-k query of relational database based on CP-net preference has been implemented.