rdf:ID和rdf:about的区别

Erica_Shea 2014-10-17

展开全文

<?xml version="1.0"?>
<rdf:RDF
   xmlns:rdf="http://www./1999/02/22-rdf-syntax-ns#"
   xmlns:rdfs="http://www./2000/01/rdf-schema#"
   xmlns:jeromedl="http://www./rdf/jeromedl.rdfs#"
   xmlns:xalan="http://xml./xslt"
   xmlns:xs="http://www./2001/XMLSchema"
   xml:lang="pl">
<rdf:RDF

    xmlns:owl="http://www./2002/07/owl#"

    xmlns="http://www./unnamed.owl#"

    xmlns:rdfs="http://www./2000/01/rdf-schema#"

    xmlns:rdf="http://www./1999/02/22-rdf-syntax-ns#"

xml:base="http://www./unnamed.owl">

<owl:Ontology rdf:about=""/>

<owl:Class rdf:ID="PizzaBase">

    <owl:disjointWith>

      <owl:Class rdf:ID="Pizza"/>

    </owl:disjointWith>

    <owl:disjointWith>

      <owl:Class rdf:ID="PizzaTopping"/>

    </owl:disjointWith>

</owl:Class>

<owl:Class rdf:about="#Pizza">

    <owl:disjointWith rdf:resource="#PizzaBase"/>

    <owl:disjointWith>

      <owl:Class rdf:about="#PizzaTopping"/>

    </owl:disjointWith>

</owl:Class>

<owl:Class rdf:about="#PizzaTopping">

    <owl:disjointWith rdf:resource="#PizzaBase"/>

    <owl:disjointWith rdf:resource="#Pizza"/>

</owl:Class>

</rdf:RDF>

1）rdf:ID和rdf:about的区别：
rdf:about的值是一个完整URIref，注意也可以是相对URI，（相对于xml:base）;
rdf:ID是对rdf:about的值的缩写，其值是一个“ XML Name”，所以，不能是数字开头，不能有“/”符号等。

例如：rdf:ID="PizzaBase" 等价于rdf:about="(xml:base)+‘#’+‘PizzaBase’ "
这个xml:base的值可以在XML文件头声明，如你例子中的，xml:base="http://www./unnamed.owl"，如果没有声明，则其值是RDF文件所放在的位置uri。

2)rdf:resource 和rdf:about

<owl:disjointWith rdf:resource="#PizzaBase"/> 是

<owl:disjointWith >
   <rdf:Description rdf:about="#PizzaBase" />
</owl:disjointWith >
的缩写。这里必须没有对资源="#PizzaBase" 做进一步的说明。所以，rdf:resource只能出现在表示属性的节点中，如这里的owl:disjointWith节点。

而 <owl:disjointWith>
             <owl:Class rdf:about="#PizzaTopping"/>
    </owl:disjointWith>
是等价于：
<owl:disjointWith >
   <rdf:Description rdf:about="#PizzaTopping" >
         <rdf:type rdf:resource="&rdfs;Class" />
   </rdf:Description>
</owl:disjointWith >

这里不能用rdf:resource了，因为声明了#PizzaTopping是一个类。

所以，我们可以看出：
说明了： <owl:Class rdf:ID="PizzaBase">
以后，后面的都是用：
<owl:disjointWith rdf:resource="#PizzaBase"/>
了。

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