SQLf3: an extension of SQLf with SQL3 features

Fuzzy Logic has been proposed for information representation and manipulation in databases, being the current tendency to study mechanisms of flexible querying to traditional databases. SQLf has been one of the efforts in this tendency. On the other hand, there are many different dialects of SQL. There are two major standards: ANSI (American National Standards Institute) SQL and an updated standard adopted in 1992, called SQL-92 or SQL2. There is also an emerging standard called SQL3 that extends SQL2 with many new features such as recursion, triggers, and objects. Then, there are versions of SQL produced by the principal vendors of database management systems. This paper looks for to continue the contribution in the area flexible querying to relational databases. Basically this contribution embraces the definition of the flexible querying language SQLf3 according to those characteristics contemplated in the norms SQL3 that can be susceptible to a fuzzy treatment.