摘要
寻找关系模式的候选码是数据库设计理论中的重要问题。通过对关系数据库规范化理论的研究,利用函数依赖和图论的有关知识,分别从属性闭包和函数依赖图的角度讨论了如何求解候选码,并给出了一些具体实例。
Seeking for candidate keys to relation scheme is an important problem in database design theory.By analyzing the standard theory of relational database and making use of the knowledge of the functional dependency and diagram,this article mainly discusses how to evaluate candidate keys to relational Database by using attribute closures and functional dependency diagrams.Some concrete examples are given.
出处
《苏州科技学院学报(自然科学版)》
CAS
2009年第4期57-60,共4页
Journal of Suzhou University of Science and Technology (Natural Science Edition)
关键词
关系模式
候选码
函数依赖
函数依赖图
属性闭包
relational model
candidate key
functional dependency
functional depending graph
attribute closures