How to get subject value from cts:triples output

Question

I am executing below query to get the list of triples from "testCollection" where predicate is "testName".

cts:triples((), sem:iri("testName"), (), (), (), cts:and-query(cts:collection-query("testCollection"))).

I can see the result in qconsole as below.

<a> <testName> <aa> .
<b> <testName> <bb> .
<c> <testName> <cc> .
<d> <testName> <dd> .
<e> <testName> <ee> .

My requirement is to get the subject / object values from the result.

for example, let's say if I want to get the values of subject, then output should be as below,

a
b
c
d
e

and for object output should be as below,

aa
bb
cc
dd
ee

Any help is appreciated.

David Ennis -CleverLlamas.com · Accepted Answer · 2023-07-06T16:21:01.867

For Your example, using cts functions, I would use the items related to that: sem:triple-subject() and sem:triple-object()

Please keep in mind that IRIs and Strings are not the same.. Your data has IRIs and your expected result is string. I present a sample that matches what You state that You want:

    xquery version "1.0-ml";

    (:

      Sample Output based on docs  - sem triples
      Also, your data suggests that all items are IRIs
    :)
    let $triples := (
      sem:triple(sem:iri("a"), sem:iri("testName"), sem:iri("aa")),
      sem:triple(sem:iri("b"), sem:iri("testName"), sem:iri("bb")),
      sem:triple(sem:iri("c"), sem:iri("testName"), sem:iri("cc"))
    )

    return for $triple in $triples
     return fn:string-join((xs:string(sem:triple-subject($triple)), xs:string(sem:triple-object($triple))), ",")

In this case, I cast as xs:string() to match your expected output and joined the subject and object by a comma for display purposes.

a,aa
b,bb
c,cc

But what about full IRIs: sem:triple(sem:iri("c"), sem:iri("testName"), sem:iri("http://www.example.com#cc"))

The result of that result would be: c, http://www.example.com#cc

I'll not take that further - just wanted to point out that you should be aware of what is actually behind an IRI since your sample was simplified.

Lastly, I would probably write a more specific SPARQL query to return just the subject and object and use xdmp:sparql() or op:from-sparql() if I were not in the cts space for my work already.

score 2 · Answer 2 · answered Jul 06 '23 at 14:42

2

You can use the sem:triple-object() and sem:triple-subject() functions to return just the object or the subject.

for $triple in cts:triples((), sem:iri("testName"), (), (), (), cts:collection-query("testCollection"))
return sem:triple-object($triple)

answered Jul 06 '23 at 14:42

Mads Hansen

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How to get subject value from cts:triples output

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