Dr. Alexander Aleksandrovich Rybanov, Assoc. Prof.
Volzhsky Polytechnic Institute -Volgograd, Russia
https://doi.org/10.53656/math2022-4-5-pra
Abstract. 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.
Keywords: relational databases; fuzzy logic; fuzzy queries; SQL; MySQL