摘要
为了能够在网络环境下使用WFS的属性查找地理实体功能,该文在介绍OGC相关规范的基础上,提出了一种SQL解析算法,该算法依据SQL逻辑规则,利用权值作为SQL子句的优先级,经过容错分析、语法分析、词法分析、SQL解析和生成XML5个步骤,实现了将SQL查询转换为符合Filter规范的xml的功能,从而简化了WFS的实体查询操作。该算法经过验证可知能够很好地实现SQL解析功能,这为采用WFS服务器的WebGIS开发提供了便利。
A sort of SQL analytical algorithm is offered in the article based on specification about OGC,which can search geographic entity function under web environment using WFS attribute.According to the rule of logic of SQL,the algorithm realizes the function of converting SQL to XML that fit in with filter specification.Using weight as priority of SQL clause,anglicizing fault toleration,grammar,accidence,SQL analyzing and creating 5 steps,then simplifies entity searching manipulation of WFS.The algorithm is confirmed to realize the analytical function of SQL well,and also pro vides much convenience for WebGIS development that uses WFS server.
出处
《计算机工程与应用》
CSCD
北大核心
2005年第26期193-196,共4页
Computer Engineering and Applications
基金
国家863高技术研究开发计划项目(编号:2002AA113150)
