数据库逻辑设计的E－S－C转换方法

The E-S--C Transformation Method of Logic Database Design

本文提出了一个基于实体－联系模型（ＥＲＭ）的数据库逻辑设计方法，即由ＥＥＲＭ到ＳＥＲＭ，ＳＥＲＭ到ＣＥＲＭ的转换方法，简称Ｈ－Ｓ－Ｃ方法。首先介绍了一个扩充实体－联系模型（ＥＥＲＭ），定义了简单实体－联系模型（ＳＥＲＭ）及规范实体－联系模型（ＣＥＲＭ），然后给出了ＥＥＲＭ到ＳＥＲＭ，ＳＥＲＭ到ＣＥＲＭ的等价转换规则。

in this paper,a method of logic database design-E-S-C transformation method is presented, which is based on entity-relationship model. Each step of the method can be implemented by algorithm,which is convenient for developing logic database system. An extended entity-relationship model is discribed,and a simple entity-relationship model and a Canonical entity-relationship model are defined. The transformation rules from extended entity-relationShip model to simple entity-relationship model iS given, then the transformation rules from simple entity-relationship model to canonical entity-relationship model. An automatic tool of logic database design using E-S-C method has been developed.