Abstract: In this paper, based on rough set theory and relational database, the relationship between rough relational database and fuzzy relational database is analyzed systematically from functional dependency, normal form and Armstrong axiom. As a consequence, we find that fuzzy functional dependency and rough functional dependency both are the generalization of classical functional dependency, and fuzzy normal form is the expansion of classical normal form, whereas rough normal form has its owner systematism, finally, RRDB and FRDB are obey Armstrong axiom in some ways from the inference rule. Keywords: functional dependency, normal form, rough set, Armstrong axiom

摘要： 本文以粗糙集理论(Rough Set Theory)和关系数据库理论为基础，从函数依赖、范式理论、Armstrong公理等方面系统地研究了粗糙关系数据库（Rough Relational Database，简称RRDB）与模糊关系数据库（Fuzzy Relational Database，简称FRDB）之间的关系。结果表明，模糊函数依赖与粗糙函数依赖均为经典函数依赖的泛化，模糊范式理论为经典范式的扩充，而粗糙范式理论自成体系，从推理规则上看，它们都不同程度地符合Armstrong公理。