Author: osma
Date: Wed Aug 19 08:46:20 2015
New Revision: 1696533
URL: http://svn.apache.org/r1696533
Log:
Add documentatin for storing original literal values (JENA-978) introduced in
3.0.0
Modified:
jena/site/trunk/content/documentation/query/text-query.mdtext
Modified: jena/site/trunk/content/documentation/query/text-query.mdtext
URL:
http://svn.apache.org/viewvc/jena/site/trunk/content/documentation/query/text-query.mdtext?rev=1696533&r1=1696532&r2=1696533&view=diff
==============================================================================
--- jena/site/trunk/content/documentation/query/text-query.mdtext (original)
+++ jena/site/trunk/content/documentation/query/text-query.mdtext Wed Aug 19
08:46:20 2015
@@ -39,6 +39,7 @@ the actual label. More details are give
- [Configuration by Code](#configuration-by-code)
- [Graph-specific Indexing](#graph-specific-indexing)
- [Linguistic Support with Lucene
Index](#linguistic-support-with-lucene-index)
+ - [Storing Literal Values](#storing-literal-values)
- [Working with Fuseki](#working-with-fuseki)
- [Building a Text Index](#building-a-text-index)
- [Deletion of Indexed Entities](#deletion-of-indexed-entities)
@@ -100,14 +101,15 @@ This is different to LARQ v1.
The following forms are all legal:
- ?s text:query 'word' # query
- ?s text:query (rdfs:label 'word') # query specific property if multiple
- ?s text:query ('word' 10) # with limit on results
- (?s ?score) text:query 'word' # query capturing also the score
+ ?s text:query 'word' # query
+ ?s text:query (rdfs:label 'word') # query specific property if
multiple
+ ?s text:query ('word' 10) # with limit on results
+ (?s ?score) text:query 'word' # query capturing also the score
+ (?s ?score ?literal) text:query 'word' # ... and original literal value
The most general form is:
- (?s ?score) text:query (property 'query string' 'limit')
+ (?s ?score ?literal) text:query (property 'query string' 'limit')
Only the query string is required, and if it is the only argument the
surrounding `( )` can be omitted.
@@ -465,6 +467,35 @@ Hence, the result set of the query will
**Note**: If the `text:langField` property is not set, the "lang" field will be
used anyway by default, because multilingual index cannot work without it.
+### Storing Literal Values
+
+New in Jena 3.0.0.
+
+It is possible to configure the text index to store enough information in the
+text index to be able to access the original indexed literal values at query
time.
+This is controlled by two configuration options. First, the `text:storeValues`
property
+must be set to `true` for the text index:
+
+ <#indexLucene> a text:TextIndexLucene ;
+ text:directory "mem" ;
+ text:storeValues true;
+ .
+
+Or using Java code, used the `setValueStored` method of `TextIndexConfig`:
+
+ TextIndexConfig config = new TextIndexConfig(def);
+ config.setValueStored(true);
+
+Additionally, setting the `langField` configuration option is recommended. See
+[Linguistic Support with Lucene Index](#linguistic-support-with-lucene-index)
+for details. Without the `langField` setting, the stored literals will not
have
+language tag or datatype information.
+
+At query time, the stored literals can be accessed by using a 3-element list
+of variables as the subject of the `text:query` property function. The literal
+value will be bound to the third variable:
+
+ (?s ?score ?literal) text:query 'word'
## Working with Fuseki
