Changes

Jump to navigation Jump to search
418 bytes added ,  10:41, 25 April 2022
</syntaxhighlight>
Please note that scoring propagation was removed with Scoring is supported within full-text expressions, by {{MarkFunction|Full-Text|Version 9.5ft:search}}. The following expressions will now yield , and by simple predicate tests that can be rewritten to {{CodeFunction|Full-Text|0ft:search}}:
<syntaxhighlight lang="xquery">
let $string := 'a b'return ft:score($string contains text 'a' ftand 'b'), for $n score $s in dbft:opensearch('factbook')//religions[text() contains text , 'orthodox'])order by $s descendingreturn $s|| ': ' || $n,
let for $string n score $s in db:= open('a bfactbook'return ft:score)//text($string )[. contains text 'aorthodox' and ]order by $s descendingreturn $string contains text s || 'b: ')|| $n
</syntaxhighlight>
Scoring is still supported within ==Thesaurus== One or more thesaurus files can be specified in a full-text expressions and by expression. The following query returns {{FunctionCode|Full-Text|ft:searchfalse}}:
<syntaxhighlight lang="xquery">
for $n score $s in ft:search('factbookhardware', 'orthodox')return $s, let $string := 'a b'return ft:score($string contains text 'acomputers' ftand 'b') using thesaurus default
</syntaxhighlight>
The reason for removing the scoring propagation was that the storage of scoring values required additional memory, even if scoring If a thesaurus is not required.employed…
<syntaxhighlight lang="xml"><thesaurus xmlns=Thesaurus=="http://www.w3.org/2007/xqftts/thesaurus"> <entry> <term>computers</term> <synonym> <term>hardware</term> <relationship>NT</relationship> </synonym> </entry></thesaurus></syntaxhighlight>
BaseX supports full-text queries using thesauri, but it does not provide a default thesaurus. This is why queries such as…the result will be {{Code|true}}:
<syntaxhighlight lang="xquery">
'computershardware' contains text 'hardwarecomputers' using thesaurus defaultat 'thesaurus.xml'
</syntaxhighlight>
will return <code>false<Thesaurus files must comply with the [https://dev.w3.org/2007/xpath-full-text-10-test-suite/TestSuiteStagingArea/TestSources/code>thesaurus.xsd XSD Schema] of the XQFT Test Suite (but the namespace can be omitted). HoweverApart from the relationship defined in [https://www.iso.org/standard/7776.html ISO 2788] (NT: narrower team, RT: related term, if the thesaurus is specifiedetc.), then custom relationships can be used. The type of relationship and the result will level depth can be <code>true</code>specified as well:
<syntaxhighlight lang="xquery">
(: BT: find broader terms; NT means narrower term :)
'computers' contains text 'hardware'
using thesaurus at 'XQFTTS_1_0_4/TestSources/usability2x.xml'relationship 'BT' from 1 to 10 levels
</syntaxhighlight>
The format of the thesaurus files must More details can be the same as the format of the thesauri provided by found in the [https://devwww.w3.org/2007TR/xpath-full-text-10-test-suite XQuery and XPath Full Text 1.0 Test Suite]. It is an XML with structure defined by an [https://dev.w3.org/2007/xpath-full-text-10-test-suite/TestSuiteStagingArea/TestSources/thesaurus.xsd XSD Schema#ftthesaurusoption specification].
==Fuzzy Querying==
</syntaxhighlight>
Fuzzy search is based on the Levenshtein distance. The maximum number of allowed errors is calculated by dividing the token length of a specified query term by 4, preserving a minimum of 1 errors. A static error distance can be set by adjusting the {{Option|LSERROR}} option (default: <code>SET LSERROR 0</code>). The query above yields two results as there is no error between the query term “house” and the text node “house”, and one error between “house” and “hous”.
Fuzzy search is also supported by A user-defined value can be adjusted globally via the full-{{Option|LSERROR}} option or via an additional argument: <syntaxhighlight lang="xquery">//a[text() contains text index.'house' using fuzzy 3 errors]</syntaxhighlight>
=Mixed Content=
=Changelog=
; Version 9.26* Updated:[[#Fuzzy_Querying|Fuzzy Querying]]: Specify Levenshtein error
; Version 9.5:
* Removed: Scoring propagation.
; Version 9.2:
 
* Added: Arabic stemmer.
; Version 8.0:
 
* Updated: [[#Scoring|Scores]] will be propagated by the {{Code|and}} and {{Code|or}} expressions and in predicates.
; Version 7.7:
 
* Added: [[#Collations|Collations]] support.
; Version 7.3:
 
* Removed: Trie index, which was specialized on wildcard queries. The fuzzy index now supports both wildcard and fuzzy queries.
* Removed: TF/IDF scoring was discarded in favor of the internal scoring model.
Bureaucrats, editor, reviewer, Administrators
13,550

edits

Navigation menu