| Summary: | 碩士 === 國立交通大學 === 資訊科學學系 === 84 === With the popularity of applied information technology, the
user interface that acts the role for communications
between the users and the computers has been
designed to be more and more friendly. For usres who want to
access a database, the query language fits as the most
important user interface. To make the query language more
user-friendly, an important issue arised is to extend the query
language with the functionality to accept and explain
imprecise queries. The
goal of this research is to design and implement an object-
oriented database query language for fuzzy querying. In the
thesis, we survey some researches on processing of
imprecise queries. According to the way to interpret the
imprecise constraints, these researches can be divided
into two categories: the ones based on relative
interpretation and those based on absolute interpretation. The
latter ones are divided furthermore into two types by the
based theory: those based on crisp sets theory and
those based on fuzzy sets theory. After analyzing the advantages
and disadvantages of these methods, we choose the
absolute interpretation method with fuzzy sets theory
to design our query language, which is named EQLf(An Object-
Oriented Database Query Language for Fuzzy Querying). EQLf is
accomplished by extending an existing query
language, namely EQL(An Easy-to-Use Query Language
for Object-Oriented Database[1]) to incorporate the capabilities
of expressing imprecise predicates and making
imprecise queries. By adopting object-oriented
engineering technology and windows programming paradgim, EQLf is
implemented to validate its excellence in being both
user-friendly and easy to learn.
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