【作者】 侯莹；

【导师】 牛纪桢；

【作者基本信息】 大连理工大学 ， 计算机应用技术， 2009， 硕士

【摘要】 随着网络技术的发展和不同形式的海量数据的积累,许多企业内部的商业数据被存储在不同的关系数据库中,运行在不同的开发平台和操作系统上,构成异构系统。因为XML已经成为Web数据交换标准,所以,在关系数据库的相关研究中,一个重要的研究领域就是基于XML的异构数据的交换与共享已经成为一个研究热点。本文对现有的异构数据的交换理论和实现方法的研究现状做了深入的研究,探讨了异构数据交换过程中相关的关键技术,重点对关系数据与XML之间的转换模型和方法进行了分析和对比,针对现有方法的运行成本高和维护效率低的缺点,本文给出了模块化的思想,以及关系模式与模块化的XML之间的的转换模型和方法BTT(Bottom ToTop,自底向上)。首先,给出表示关系模式的向量模型,保存了关系结构与属性信息和用户自定义约束信息;同时根据XML是典型的树状结构的特点,给出了XML模式树模型。其次,在关系模式的向量模型及XML模式树模型的基础上,给出了BTT方法的映射原理及其映射规则,该方法不仅保持了关系模式的结构信息、属性信息和约束信息的完整保留,而且自底向上的映射顺序则在没有牺牲转换效率的情况下,完成了模块化的封装与重用,使得转换后的XML Schema文档在维护效率上的性能优势。再则,通过大量的实验数据,证明了与传统的模式转换方法相比,BTT方法在维护效率上的明显优势。最后,本文结合全国大集中模式下的计费系统的实际项目,将BTT方法应用其中,具有很大的现实意义。更多还原

【Abstract】 With the development of network technology and the accumulation of different forms of data, much business data in companies is stored in different relational databases, run on different developing platforms and operating systems, which constitutes a heterogeneous system. Because XML has become the Web data exchange standard, so in the area of relational database related research, an important area of realizing the exchange and sharing of heterogeneous data based on XML has become a research hotspot.In this paper, the existing heterogeneous data exchange theory and implementation method are studied deeply, the key technology is discussed, the models and methods of conversion between relational data and XML are analyzed and compared. Against the state of high cost and low efficiency, a modular idea is proposed, a new conversion method BTT (Bottom To Top) between relational database and XML is proposed too. First of all, a vector model of relational database and a XML schema tree model are proposed, preserving the structure, properties and user-defined constraint information. Second, based on vector model and XML schema tree model, a new conversion methods of BTT and its mapping rules are proposed. BTT not only maintains the structure information, attribute information and constraint information to convert correctly, but also accompletes modular’s packaging and reuse, making the maintenance for transformed XML document in high efficiency. Furthermore, through a large number of experimental data to prove that comparing with other method, BTT has an obvious advantage in the maintenance. Finally, combining the billing system under nation centralized mode, BTT is applied which has a great practical significance.更多还原