超媒体数据库三层数据模型

DBHM Hypermedia Database 3 -Layer Data Model

提出了超媒体数据库应用的三层数据模型 (命名为 DBHM) ,并给出了使用 DBHM方法设计的一个实例 .DBHM模型由上至下包括表现层、逻辑层、存储层等三个层次 ,各自对应于导航模型、对象模型以及关系模型 .首先使用面向对象的分析方法对实际应用需求建模 ,通过对象模型的建立 ,确定应用的基本结构 ,并由此按一定的映射关系分别得出导航模型和关系模型 ,从而将导航表现与数据库结构设计有机地结合起来 .目标是以 DBHM为基础 ,提供一套实用的设计方法 。

This article described a 3 layer designing model (Named DBHM) for hypermedia database applications and illustrated the approach using a small application. The DBHM model from top to bottom includes representation layer, logic layer and storage layer, which correspond to navigation model, object model and relational model respectively. Firstly, object oriented analysis method is used to construct a model for the application. After completion of the object model, the basic architecture of the application is settled. Then the correspondent navigation model and relational model can be gained through certain mapping relation. So, navigation features are closely combined with database structure. Its objective is to use the DBHM approach as the basis for the construction of reliable data centric hypermedia applications.