【摘要】 讨论空间应用的一种面向问题的表达方法与实现机制。为解决空间应用的描述问题,在建立时空一体化空间数据模型基础上,定义了对SQL进行扩展的时空复合查询语言,实现了对空间应用问题的非过程化描述;研究复杂空间应用的表达问题,讨论时空复合查询语言的限制,并在语言中引入流机制,通过空间应用问题的组合实现更为复杂的空间应用,并支持空间数据分布式计算;最后给出若干空间应用实例及其面向问题的表达。更多还原

【Abstract】 This paper proposes an approach to represent and implement spatial application by problem oriented method.To descript kinds of spatial applications in non-procedural way,this paper begins with constructing a spatio-temporal composite spatial data model,defines spatio-temporal query language based on SQL.Then limitation of query language in complicate situation is considered.Flow control mechanism is imported to implement more complicate spatial application by composing simple applications,spatial data distributed computing is also supported.At last,several examples are given to show problem oriented representation of spatial application.更多还原