ER模型的语义概念集合和表示法

Semantic Concept Set of the ER Model and Its Representation

ER模型能够清晰地表达现实世界的实体、联系和约束。主要从数据结构、数据操作、数据的约束条件3个方面归纳了ER模型所支持的语义概念集合,介绍了几种在应用中使用比较广泛的表示法,并对它们所支持的概念集合、图形表示法和CASE支持工具等进行了比较。

The ER model can be used to express the entity, connection and restraint of the actual world, sums up the semantic concept set supported by ER model mainly from the data structure, data operation and data restraint condition, introduces several kinds of the representations that are used more widely, and makes the comparison of the concept set and graphic representation supported by these representations and the tools supported by CASE.