【摘要】 XML 正在成为 Internet上数据描述和交换的标准 ,用一些重要的面向对象的特征扩展基于高级数据模型上的以规则为基础的 XML查询语言 XML - RL .首先用元素层次 ,多重继承和多态扩展了 XML - RL数据模型 .然后扩展 XML - RL以支持多态元素 ,多态引用 ,独占元素和独占引用 .更多还原

【Abstract】 XML is emerging as the dominant standard for data representation and exchange over the Web. This paper extends XML RL which is a rule based XML query language based on higher level data model, with some important object oriented features such as element hierarchy, multiple inheritance, polymorphism. The paper first extend the XML RL data model with element hierarchy, multiple inheritance and polymorphism. Then it extend XML RL to support polymorphic element and reference as well as exclusive element and reference.更多还原