摘要
在GIS中对空间数据库的操作,难点在于采用统一的查询语言SQL对空间数据的操纵。该问题的实现需要对现有SQL语言进行扩展,使之能够识别和处理对空间数据进行操纵的语句。本文围绕分析空间查询语句结构的全过程,采用中间件对标准的SQL语言功能进行扩展。提出了一种以语法树生成原理实现标准SQL语句和扩展SQL语句的分析和进行功能分解的具体方法,展示了以中间件封装空间操作的SQL词法分析、SQL语法分析的具体实现,并给出了具体的算例。本文提出的方法为进一步研究与开发空间查询语言,空间数据操纵语言的实现提供了基础。
It is dificult to use identic＇,d SQL operating spatial database in GIS. In order to solving this problem SQL language will be extended and extended SQL will be able to distinguish and deal with spatial data manipulation. On the basis of analyzing structure of spatial SQL, the author in this paper, ueses the middleware function to extend standerd SQL language, puts forward a method that can be distinguish and divide standard SQL and extended SQL by the theory of generating syntax tree, demonstrates the specific realization of SQL Lexical Analysis and SQL syntax analysis hy the middleware packaging spatial operation, and carries on hy the example. The research has provided the foundation for further studied and development on spatial SQL and realization of spatial data manipulation language.
出处
《测绘科学》
CSCD
北大核心
2008年第4期192-193,共2页
Science of Surveying and Mapping
关键词
空间操纵
语法分析
语法树
SQL
SQL扩展
spatial data manipulation language
syntax analysis
syntax tree
SQL
extended SQL
