A PRACTICAL METHOD FOR IMPLEMENTING FUZZY QUERIES FOR RELATIONAL DATABASES

Information systems that use databases are flexible to the extent that they allow users to request the data they need. SQL is limited to precise data processing and does not directly express fuzzy concepts of natural language. Therefore, giving SQL some flexibility can help users improve interaction with information systems without requiring them to learn a completely new language. The task of reducing the labor intensity of the process of integrating the mechanisms of fuzzy requests to existing information systems is urgent. The article shows the limitations of clear queries, considers various forms of fuzzy queries. Known approaches to implementing fuzzy queries to relational databases were analyzed. Provides a detailed analysis of fuzzy queries, as well as their conversion to standard SQL queries using MySQL. The proposed method for implementing the ability to work with fuzzy queries is based on expanding a clear database with stored functions, without changing the structure and composition of its tables. The advantages of the method are: increased readability and understanding of SQL queries; ease of integration with existing databases of information systems; flexible adjustment of the linguistic variable membership function in accordance with the needs of the database user. The application of the method is shown by the example of adapting a MySQL database. The proposed adaptation method can be widely used to implement fuzzy queries to databases of various DBMS that support work with stored functions.