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.
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。