A Knowledge-based Method of Multilevel Query in Relational Database

There is a kind of query that users tend to use fuzzy concepts to express the query requirements. In the relational database, the query based on concepts as inputs cannot be directly executed. The basic method converts users' fuzzy concepts into precise concepts based on the domain knowledge. In practice, a fuzzy condition is often composed of the high and multilevel concepts, so its conversion of the concepts is very complex, and its efficiency is poor. A new knowledge-based method of multilevel query is proposed in this paper, and it is achieved on generalized data. Experiments show that the query efficiency of the method proposed in the paper is better than the basic method on multiple levels. It may provide efficient methods for the query about housing products in rural town, and it can meet the needs of customers with different knowledge, and it has higher practical value.