地理信息.滤波器编码

[中文适用范围]： 该国际标准描述了系统中立语法的 XML 和 KVP 编码，用于表达投影、选择和排序子句，统称为查询表达式。 这些组件是模块化的，旨在与引用本国际标准的其他标准一起或单独使用。 示例1 ISO 19142 使用了这些组件中的一些或全部。 该国际标准定义了一个名为 AbstractQueryExpression 的抽象组件，其他规范可以从该组件派生具体查询元素来实现查询操作。 该国际标准还定义了一个附加的抽象查询组件，名为 AbstractAdhocQueryExpresison，它派生自 AbstractQueryExpression，其他规范可以从中子类化遵循以下查询模式的具体查询元素： 抽象查询元素，服务规范可以从中子类化具体查询元素它实现一个查询操作，允许客户端指定资源类型列表、可选的投影子句、可选的选择子句和可选的排序子句来查询满足选择子句的资源子集。 此模式称为即席查询模式，因为服务器在提交查询进行处理之前并不知道该查询。 这与存储的查询表达式形成对比，存储的查询表达式是通过名称或标识符存储并可以调用的。 该国际标准还描述了 select 子句的系统中立表示的 XML 和 KVP 编码。 XML 表示很容易验证、解析并转换为检索或修改存储在某些持久对象存储中的对象实例所需的服务器特定语言。 示例 2 XML 编码的过滤器可以转换为 SQL SELECT 语句的 WHERE 子句，以获取存储在基于 SQL 的关系数据库中的数据。 类似地，XML 编码的过滤器表达式可以转换为 XPath 或 XPointer 表达式，以便从 XML 文档中获取数据。 该国际标准定义了以下谓词的 XML 编码。 a) 一组标准的逻辑谓词：and、or 和 not。 b) 一组标准的比较谓词：等于、不等于、小于、小于或等于、大于、大于或等于、like、is null 和 Between。 c) 一组标准的空间谓词：相等、不相交、接触、内部、重叠、交叉、相交、包含、在指定距离内、超出指定距离和 BBOX。 d) 一组标准的时间谓词：after、before、begins、beginning by、contains、during、ends、equals、meets、met by、overlaps 和overlaped by。 e) 用于测试对象的标识符是否与指定值匹配的谓词。 该国际标准定义了元数据的 XML 编码，允许服务声明它支持哪些一致性类、谓词、运算符、操作数和函数。 该元数据称为过滤器功能。 [外文原描述]： ISO 19143:2010 describes an XML and KVP encoding of a system neutral syntax for expressing projections, selection and sorting clauses collectively called a query expression. These components are modular and intended to be used together or individually by other International Standards which reference ISO 19143:2010. ISO 19143:2010 defines an abstract component, named AbstractQueryExpression, from which other specifications can subclass concrete query elements to implement query operations. It also defines an additional abstract query component, named AbstractAdhocQueryExpresison, which is derived from AbstractQueryExpression and from which other specifications can subclass concrete query elements which follow the following query pattern: An abstract query element from which service specifications can subclass a concrete query element that implements a query operation that allows a client to specify a list of resource types, an optional projection clause, an optional selection clause, and an optional sorting clause to query a subset of resources that satisfy the selection clause. This pattern is referred to as an ad hoc query pattern since the server in not aware of the query until it is submitted for processing. This is in contrast to a stored query expression, which is stored and can be invoked by name or identifier. ISO 19143:2010 also describes an XML and KVP encoding of a system-neutral representation of a select clause. The XML representation is easily validated, parsed and transformed into a server-specific language required to retrieve or modify object instances stored in some persistent object store. ISO 19143:2010 defines the XML encoding for the following predicates. - A standard set of logical predicates: and, or and not. - A standard set of comparison predicates: equal to, not equal to, less than, less than or equal to, greater than, greater than or equal to, like, is null and between. - A standard set of spatial predicates: equal, disjoint, touches, within, overlaps, crosses, intersects, contains, within a specified distance, beyond a specified distance and BBOX. - A standard set of temporal predicates: after, before, begins, begun by, contains, during, ends, equals, meets, met by, overlaps and overlapped by. - A predicate to test whether the identifier of an object matches the specified value. ISO 19143:2010 defines the XML encoding of metadata that allows a service to declare which conformance classes, predicates, operators, operands and functions it supports. This metadata is referred to as Filter Capabilities.