MarkLogic 9 Product Documentation

Semantics Developer's Guide — Chapter 5

Unmanaged Triples

Triples that included as part of an XML or a JSON document and have an element node of sem:triple are called unmanaged triples, sometimes referred to as embedded triples. These unmanaged triples must be in the MarkLogic XML or JSON format defined in the schema for sem:triple (semantics.xsd).

Unmanaged triples cannot be modified with SPARQL Update. Use XQuery or JavaScript to modify these triples. See Updating Triples for more details.

With unmanaged triples, MarkLogic works like a triple store and a document store. You have the functionality of a triple store and a document store for your data.

This example inserts an unmanaged triple into an XML document (Article.xml):

xquery version "1.0-ml";
import module namespace sem = "http://marklogic.com/semantics" 
  at "/MarkLogic/semantics.xqy";

xdmp:document-insert("Article.xml",
<article>
  <info>
   <title>News for April 9, 2013</title>
    <sem:triples xmlns:sem="http://marklogic.com/semantics">
      <sem:triple>
       <sem:subject>http://example.com/article</sem:subject>
       <sem:predicate>http://example.com/mentions</sem:predicate>
       <sem:object datatype="http://www.w3.org/2001/XMLSchema#string">London</sem:object>
      </sem:triple>
    </sem:triples>
  </info>
</article>)

You can leave out the sem:triples tag, but you cannot leave out the sem:triple tags.

An XML or JSON document can contain many kinds of information, along with the triples.

This example shows a suspicious activity report document that contains both XML and triples:

<SAR>
  <title>Suspicious vehicle...Suspicious vehicle near airport</title>
  <date>2014-11-12Z</date>
  <type>observation/surveillance</type>
  <threat>
    <type>suspicious activity</type>
    <category>suspicious vehicle</category>
  </threat>
  <location>
    <lat>37.497075</lat>
    <long>-122.363319</long>
  </location>
  <description>A blue van with license plate ABC 123 was observed parked behind the airport sign...
    <sem:triple>
      <sem:subject>IRIID</sem:subject>
      <sem:predicate>isa</sem:predicate>
      <sem:object datatype="http://www.w3.org/2001/XMLSchema#string">license-plate</sem:object>
    </sem:triple>
    <sem:triple>
      <sem:subject>IRIID</sem:subject>
      <sem:predicate>value</sem:predicate>
      <sem:object datatype="http://www.w3.org/2001/XMLSchema#string">ABC 123</sem:object>
    </sem:triple>
  </description>
</SAR>

Unmanaged triples ingested into a MarkLogic database are indexed by the triple index and stored for access and query by SPARQL. Here is another representation of the same information:

You can also embed triples into JSON documents. Here is how you would insert a triple using JavaScript:

declareUpdate();
var sem = require("/MarkLogic/semantics.xqy");
xdmp.documentInsert( 
 "testDoc.json", {
  "my": "data","triple":{  
    "subject": "http://example.org/ns/dir/js/",  
    "predicate": "http://xmlns.com/foaf/0.1/firstname/",  
    "object": {"datatype" : "http://www.w3.org/2001/XMLSchema#string",
     "value": "John" 
      } 
    }
  } 
)

Here is the triple embedded in a JSON document:

{
"my": "data",
"triple":{
  "subject": "http://example.org/ns/dir/js/",
  "predicate": "http://xmlns.com/foaf/0.1/firstname/",
  "object": {
    "datatype" : "http://www.w3.org/2001/XMLSchema#string",
      "value":"John"
    }
  }
}

You can do the same document insert with XQuery:

xquery version "1.0-ml";
import module namespace sem = "http://marklogic.com/semantics" 
  at "/MarkLogic/semantics.xqy";

xdmp:document-insert("myData.xml",
 <sem:triples xmlns:sem="http://marklogic.com/semantics">
   <sem:triple>
    <sem:subject>http://example.org/ns/dir/js/</sem:subject>
    <sem:predicate>http://xmlns.com/foaf/0.1/firstname/</sem:predicate>
    <sem:object datatype="http://www.w3.org/2001/XMLSchema#string">John</sem:object>
   </sem:triple>
  </sem:triples>
)

When triples are embedded in an XML or JSON document as unmanaged triples, they can include additional information about the triple along with additional metadata (time/date information, bitemporal information, source of the triple). You can add useful information to the XML or JSON file (like the provenance of the triple). When you update the triple, you update the document and the triple together.

In addition to adding triples to a document, you can use a template to identify content to be indexed as triples. See Using a Template to Identify Triples in a Document for more information about templates.

<article>
 <info>AP Newswire - Nixon went to China</info>
 <triples-context>
  <confidence>80</confidence>
  <pub-date>2011-10-14</pub-date>
  <source>AP Newswire</source>
 </triples-context>
 <sem:triple xmlns:sem="http://marklogic.com/semantics"> 
  <sem:subject>http://example.org/news/Nixon</sem:subject>
  <sem:predicate>http://example.org/wentTo</sem:predicate>
  <sem:object datatype="http://www.w3.org/2001/XMLSchema#string">China</sem:object>
 </sem:triple>
</article>

xquery version "1.0-ml";
import module namespace sem = "http://marklogic.com/semantics" 
  at "/MarkLogic/semantics.xqy";

sem:sparql('
  SELECT ?country
  WHERE {
    <http://example.org/news/Nixon> <http://example.org/wentTo> ?country
  }
  ',
  (),
  (),
  cts:and-query( (
    cts:path-range-query( "//triples-context/confidence", ">=", 80) ,
    cts:path-range-query( "//triples-context/pub-date", ">", xs:date("1974-01-01")),
    cts:or-query( (
      cts:element-value-query( xs:QName("source"), "AP Newswire" ),
      cts:element-value-query( xs:QName("source"), "BBC" )
   ) )
 ) )
)

xquery version "1.0-ml";
xdmp:document-get-permissions("/example.json")

=>
<sec:permission xmlns:sec="http://marklogic.com/xdmp/security">
  <sec:capability>read</sec:capability>
  <sec:role-id>11180836995942796002</sec:role-id>
</sec:permission>
<sec:permission xmlns:sec="http://marklogic.com/xdmp/security">
  <sec:capability>update</sec:capability>
  <sec:role-id>11180836995942796002</sec:role-id>
</sec:permission>

xdmp:document-set-permissions(
  "/example.json",
  (xdmp:permission("sparql-update-user","update"),
  xdmp:permission("sparql-update-user","read"))
)

let $q := '
SELECT 
  ?derivation
WHERE {
  <http://example.com/prov/trader/>
   <http://www.w3.org/ns/prov#wasDerivedFrom/> ?derivation
  }
  '
return
  sem:sparql(
    $q,
    (),
    (),
    sem:store(
      (),
      cts:period-range-query(
        "valid",
        "ISO_CONTAINS",
      cts:period(
        xs:dateTime("2014-04-01T16:10:00"),
        xs:dateTime("2014-04-01T16:12:00")) )
    )
  )