摘要
数据模型将实际生产工作中的业务概念和需求抽象成一组集合,集合中定义了实体的结构、操作和约束关系,并且以数据字典为存储载体的数据模型易于被程序调用,灵活控制程序功能。本文以重庆矿业权设置方案数据库为数据依托,分析工作需求和业务流程,建立了关于矿业权设置方案专题图层提取工作的数据模型,将模型所涉及的编码、属性结构、属性数据、图元参数、空间坐标以及图件层级关系等以数据字典技术进行管理,开发基于该数据字典的专题图层提取程序,完成了根据用户自由设定的条件从基础数据库中提取用户所需专题图层的功能。数据模型和数据字典的分析建立过程是本文探讨的核心问题。
Operational concepts and requirements of actual production are extracted by the data model in a series of collections that define the entity structure, operation and relationship stress. The data model is easy to be invoked by a program control function with flexible data dictionary as a storage medium. Based on the basis of the mining program in Chongqing, this paper introduced with a necessary job analysis and process operation data model on the installation of the mining plan to extract the thematic layer; the coding involved, the attribute structure, attribute data, the primitive spatial coordinates and hierarchical relationships between parameter maps are managed by the data dictionary with which generated the extraction process of the thematic layer and its function involved with the needs of users who are free to set the terms in the database underlying. The process of creating the data model and analysis of the data dictionary is at the heart of this document.
出处
《国土资源信息化》
2013年第3期69-72,共4页
Land and Resources Informatization
关键词
数据模型
专题图层提取
数据字典
MAPGIS二次开发
Data model
Extraction of the thematic layer
Data dictionary
MapGIS
Secondary development
