论文标题
改进的通用ER模式,用于信息系统的概念建模
An Improved Generic ER Schema for Conceptual Modeling of Information Systems
论文作者
论文摘要
实体关联(ER)模型被广泛用于创建用于在信息系统开发领域中建模应用程序域的ER模式。但是,当将ER模式转换为关系数据库架构(RDS)时,有关ER模式的一些重要信息可能不会在RDS上有意义地表示。这会在转换过程中导致信息丢失。尽管以前的一些研究提出了解决情况的解决方案,但问题仍然存在。因此,在这项正在进行的研究中,我们希望改善所提出的解决方案,并最大程度地利用ER中的信息保存到关系转换过程。基数比率约束,角色名称,复合属性和某些关系类型是转换过程中经常丢失的信息之一。 ER模型中的缺陷和转换方法似乎会导致这种情况。我们认为,如果丢失的信息已解决;从ER模式到其RDS应该存在一对一的映射。我们根据启发式研究方法修改了ER模型和转换算法,以消除缺陷,从而实现一对一的映射。我们应该证明为任何实际应用程序都存在映射。我们创建了一个通用的ER模式 - 一种以符号形式代表任何现象的ER模式 - 并使用它来表明对于任何现实世界应用,都存在一对一的映射。在本文中,我们探讨了代表任何现实世界应用的通用ER模式及其优势比其前辈。
The Entity-Relationship (ER) model is widely used for creating ER schemas for modeling application domains in the field of Information Systems development. However, when an ER schema is transformed to a Relational Database Schema (RDS), some important information on the ER schema may not be represented meaningfully on the RDS. This causes a loss of information during the transformation process. Although, several previous researches have proposed solutions to remedy the situation, the problem still exists. Thus, in this on-going research, we wish to improve the proposed solutions and maximize information preservation in the ER to relational transformation process. Cardinality ratio constraints, role names, composite attributes, and certain relationship types are among the information frequently lost in the transformation process. Deficiencies in the ER model and the transformation method seems to cause this situation. We take the view that if the information lost is resolved; a one-to-one mapping should exist from the ER schema to its RDS. We modified the ER model and the transformation algorithm following a heuristic research method with a view to eliminating the deficiencies and thereby achieving a one-to-one mapping. We should show that the mapping exists for any real-world application. We create a generic ER schema - an ER schema that represents any phenomena in symbolic form - and use it to show that a one-to-one mapping exists for any real-world application. In this paper, we explore our generic ER schema and its advantages over its predecessors in view of representing any real-world application.