MATLAB在求解关系模式上全部候选关键字中的应用

APPLICATION OF MATLAB IN FINDING ALL CANDIDATE KEYS FOR RELATIONAL SCHEMA

本文描述了MATLAB中的数值数组、元胞数组与关系模式上的属性集、函数依赖集之间的对应关系 ,实现了属性集运算的MATLAB数组表示 ,给出了关系模式中计算属性集闭包、求解候选关键字的M函数。在应用 [1]中的替换算法的基础上 ,本文给出了一个求解关系模式上全部候选关键字的M函数。实际应用表明 ,本文介绍的MATLAB程序代码简洁、运行可靠、求解正确。

This paper describes the corresponding relation between the numeric arrays,cell arrays in MATLAB and the sets of attribute,the sets of functional dependencies on relational schema,implements the operations of sets of attribute with the arrays in MATLAB,and gives several M functions for calculating the closure of attribute sets and finding one candidate key.With the replacing method in,a M function which can find all candidate keys for a relational schema is given.The application shows that the MATLAB program introduced by this paper have the character of compact codes,reliable run and solving rightly.