无法使用SPARQL来预定义层次结构 [英] Can't PREFIX hierarchies with SPARQL

问题描述

我需要像这样在我的URL中表示一个层次结构:

I have a need to represent a hierarchy in my URL's like this:

http://www.me.org/
-----------------root1/
-----------------------level1/
------------------------------level2/etc

我想定义PREFIX，并在SPARQL查询中使用它们，如下所示:

I want to define PREFIX's and used them in a SPARQL query like this:

PREFIX root1: <http://www.me.org/root1/>

select * where {
    ?s ?p root1:level1/level2/etc .
} limit 100

这将在ARQ中失败，并显示以下错误:

This will fail in ARQ with the following error:

Encountered " "/" "/ "" at line 10, column 43.
Was expecting one of:
    "values" ...
    "graph" ...
...

我应该这样在我的URL中表示一个层次结构，还是SPARQL和PREFIX的使用仅限于一个级别?

Should I be able to represent a hierarchy in my URL's like this or is SPARQL and PREFIX use limited to a single level ?

推荐答案

您可以在前缀声明中使用相对URI:

You can use relative URIs in prefix declarations:

BASE <http://example/>
PREFIX root1:  <root1/>
PREFIX level1: <root1/level1/>
PREFIX level2: <root1/level1/level2/>

SELECT * {
  ?s ?p  level2:etc .
}

避免了在URI中重复部分字符串的一些开销.

which avoids some of the overhead of repeating part-strings in URIs.

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