Fuzzy Improvement of the Sql
نویسنده
چکیده
Structured Query Language (SQL) is used to obtain data from relational databases. Fuzzy improvement of SQL queries has advantages in cases when the user cannot unambiguously define selection criteria or when the user wants to examine data that almost meet the given criteria. In this paper we examine a realisation of the fuzzy querying concept. For this purposes the fuzzy generalized logical condition for the WHERE part of the SQL is created. It allows users to create queries by linguistic terms. The proposed model is an extension of the SQL so that no modification inside databases has to be undertaken.
منابع مشابه
Fuzzy Equi–Join and Its Evaluation
We propose a new measure of fuzzy equality comparison based on the similarity of possibility distributions. we define a fuzzy equi–join based on the new fuzzy equality comparison, and allow threshold values to be associated with predicates of the join condition. A sort–merge join algorithm based on a partial order of intervals is used to evaluate the fuzzy equi-join. In order for the evaluation...
متن کاملConversion of Fuzzy Query into SQL Query
Traditional database systems can deal with perfect data. But lot of information is present in imperfect form due to vagueness or imprecision. [16] Fuzzy set theory has been applied to deal with imperfections of data and to enhance the accessibility of databases. When users work with usual software tools they have to change their many valued logical thinking (approximate reasoning) into the twov...
متن کاملNew architecture of fuzzy database management systems
Fuzzy relational data bases have been extensively studied in a theoretical level. Unfortunately, the repercussions of these works on the practical plan are negligible. Medina et al. have developed a server named fuzzy SQL, supporting flexible queries and based on a theoretic model called GEFRED. This server has been programmed in PL/SQL language under Oracle database management systems. To mode...
متن کاملEfficient Processing of Nested Fuzzy SQL Queries in a Fuzzy Database
ÐIn a fuzzy relational database where a relation is a fuzzy set of tuples and ill-known data are represented by possibility distributions, nested fuzzy queries can be expressed in the Fuzzy SQL language, as defined in [25], [23]. Although it provides a very convenient way for users to express complex queries, a nested fuzzy query may be very inefficient to process with the naive evaluation meth...
متن کاملManagement of an estate agency allowing fuzzy data and flexible queries
As main result of all our previous work we have now available a FSQL Server for Oracle Databases pro grammed in PL SQL This server allows us to query either a Fuzzy or Classic Relational Database with the FSQL language Fuzzy SQL The FSQL language is an extension of the SQL language which permits us to write exible or fuzzy conditions in our queries to a fuzzy or traditional database In this wor...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2011