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This module [[Module Library|XQuery Module]] extends the [httphttps://www.w3.org/TR/xpath-full-text-10 W3C Full Text Recommendation] with some useful [[Querying#Functions|XQuery functions]]: The index can be directly accessed, full-text fulltext results can be marked with additional elements, or the relevant parts can be extracted. Moreover, the score value, which is generated by the <code>{{Code|contains text</code> }} expression, can be explicitly requested from items.  =Conventions= All functions and errors in this module are introduced with assigned to the <code>ft:</code> prefix, which is linked to the statically declared <codenowiki>http://basex.org/modules/ft</nowiki></code> namespace, which is statically bound to the {{Code|ft}} prefix.<br/>

 {|width='100%'

| valign='top' width='90120' | '''Signatures'''|<code><b>{{Func|ft:search|$db as xs:string, $terms as item()*|text()*}}<br/b>({{Func|ft:search|$db as xs:string, $node terms as nodeitem()*, $text options as xs:stringmap(*) as ?|text()</code>*}}

| valign='top' | '''Summary'''|Performs a Returns all text nodes from the full-text index request on of the specified XML node and returns all text nodes database {{Code|$db}} that contain the string <code>specified {{Code|$textterms}}.<br/code>. The index options used for tokenizing the input and building the full-text options are used for searching, i.ewill also be applied to the search terms.As an example, if the index terms were have been stemmed, the search string will be stemmed as well.The {{Code|$options}} argument can be used to control full-text processing. The following options are supported (the introduction on [[Full-Text]] processing gives you equivalent expressions in the XQuery Full-Text notation):* {{Code|mode}}: determines the mode how tokens are searched. Allowed values are {{Code|any}}, {{Code|any word}}, {{Code|all}}, {{Code|all words}}, and {{Code|phrase}}. {{Code|any}} is the default search mode.* {{Code|fuzzy}}: turns fuzzy querying on or off. Allowed values are {{Code|true}} and {{Code|false}}. By default, fuzzy querying is turned off.* {{Code|wildcards}}: turns wildcard querying on or off. Allowed values are {{Code|true}} and {{Code|false}}. By default, wildcard querying is turned off.* {{Code|ordered}}: requires that all tokens occur in the order in which they are specified. Allowed values are {{Code|true}} and {{Code|false}}. The default is {{Code|false}}.* {{Code|content}}: specifies that the matched tokens need to occur at the beginning or end of a searched string, or need to cover the entire string. Allowed values are {{Code|start}}, {{Code|end}}, and {{Code|entire}}. By default, the option is turned off.* {{Code|scope}}: defines the scope in which tokens must be located. The option has following sub options:** {{Code|same}}: can be set to {{Code|true}} or {{Code|false}}. It specifies if tokens need to occur in the same or different units.** {{Code|unit}}: can be {{Code|sentence}} or {{Code|paragraph}}. It specifies the unit for finding tokens.* {{Code|window}}: sets up a window in which all tokens must be located. By default, the option is turned off. It has following sub options:** {{Code|size}}: specifies the size of the window in terms of ''units''.** {{Code|unit}}: can be {{Code|sentences}}, {{Code|sentences}} or {{Code|paragraphs}}. The default is {{Code|words}}.* {{Code|distance}}: specifies the distance in which tokens must occur. By default, the option is turned off. It has following sub options:** {{Code|min}}: specifies the minimum distance in terms of ''units''. The default is {{Code|0}}.** {{Code|max}}: specifies the maximum distance in terms of ''units''. The default is {{Code|∞}}.** {{Code|unit}}: can be {{Code|words}}, {{Code|sentences}} or {{Code|paragraphs}}. The default is {{Code|words}}.

| valign='top' | '''Errors'''|'''[[XQuery {{Error|db:open|Database Module#Errors}} The addressed database does not exist or could not be opened.<br/>{{Error|db:no-index|Database Module#BaseX Errors|BASX0001]]''' is raised if }} the full-text index is not available.<br/>'''[[XQuery Errors{{Error|options|#BaseX Errors|BASX0002]]''' is raised if a referenced node is not stored in a database (i.e., references a main-memory XML fragment)}} the fuzzy and wildcard option cannot be both specified.

| valign='top' | '''Examples'''

* {{Code|ft:search("DB", "QUERY")}}: Return all text nodes of the database {{Code|DB}} that contain the term {{Code|QUERY}}.* Return all text nodes of the database {{Code|DB}} that contain the numbers {{Code|2010}} and {{Code|2020}}:<br/><code>ft:search(."DB", ("2010", "QUERY2020"), map { 'mode': 'all' })</code> returns all * Return text nodes of the currently opened database that contain the string terms {{Code|A}} and {{Code|B|}} in a distance of at most 5 words:<syntaxhighlight lang="xquery">ft:search("db", ("A", "B"), map { "mode": "all words", "distance": map { "max": "5", "unit": "words" }})</syntaxhighlight>* Iterate over three databases and return all elements containing terms similar to {{Code|Hello World}} in the text nodes:<syntaxhighlight lang="xquery">let $terms := "QUERYHello Worlds"let $fuzzy := true()for $db in 1 to 3let $dbname := 'DB' || $dbreturn ft:search($dbname, $terms, map { 'fuzzy': $fuzzy })/..</syntaxhighlight>

==ft:markcontains== {|width='100%'

| valign='top' width='90120' | '''Signatures'''|<code><b>{{Func|ft:mark</b>(contains|$nodes input as nodeitem()*) , $terms as nodeitem()*</code>|xs:boolean}}<br /><code><b>{{Func|ft:mark</b>(contains|$nodes input as nodeitem()*, $tag terms as xs:stringitem() *, $options as nodemap(*)*</code>?|xs:boolean}}

| valign='top' | '''Summary'''|Puts a marker element around Checks if the specified {{Code|$input}} items contain the resulting <code>specified {{Code|$nodesterms}}.<br/code> of a fullThe function does the same as the [[Full-Text]] expression {{Code|contains text index request}}, but options can be specified more dynamically.<br />The {{Code|$options}} are the same as for [[#ft:search|ft:search]], and the following ones in addition:* {{Code|case}}: determines how character case is processed. Allowed values are {{Code|insensitive}}, {{Code|sensitive}}, {{Code|upper}} and {{Code|lower}}. By default tag name of the marker element , search is case insensitive.* {{Code|diacritics}}: determines how diacritical characters are processed. Allowed values are {{Code|insensitive}} and {{Code|sensitive}}. By default, search is diacritical insensitive.* {{Code|stemming}}: determines is tokens are stemmed. Allowed values are {{Code|true}} and {{Code|false}}. By default, stemming is <code>mark</code>turned off. An alternative tag name can be chosen via * {{Code|language}}: determines the optional <code>$tag</code> argumentlanguage. This option is relevant for stemming tokens.<br />Note that the XML node to be transformed must be an internal "database" nodeAll language codes are supported. The <code>transform</code> expression can be used to apply the method to a main-memory fragment (see example)default language is {{Code|en}}.

| valign='top' | '''Errors'''|'''[[XQuery Errors#BaseX Errors{{Error|options|BASX0002]]''' is raised if a referenced node is not stored in a database (i.e., references a main-memory XML fragment).<br />'''[[XQuery Errors#Functions Errors|FOCA0002]]''' is raised if <code>$name</code> is no valid QName}} specified options are conflicting.

| valign='top' | '''Examples'''

* Checks if {{Code|jack}} or {{Code|john}} occurs in the input string {{Code|John Doe}}:<syntaxhighlight lang="xquery">ft:contains("John Doe", ("jack", "john"), map { "mode": "any" })</syntaxhighlight>* Calls the function with stemming turned on and off:<syntaxhighlight lang="xquery">(true(), false()) ! ft:contains("Häuser", "Haus", map { 'stemming': ., 'language':'de' })</syntaxhighlight>|} ==ft:mark== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|ft:mark|$nodes as node()*|node()*}}<br />{{Func|ft:mark|$nodes as node()*, $name as xs:string|node()*}}|-| '''Summary'''|Puts a marker element around the resulting {{Code|$nodes}} of a full-text request.<br />The default name of the marker element is {{Code|mark}}. An alternative name can be chosen via the optional {{Code|$name}} argument.<br />Please note that:* The full-text expression that computes the token positions must be specified as argument of the <code>ft:mark()</code> function, as all position information is lost in subsequent processing steps. You may need to specify more than one full-text expression if you want to use the function in a FLWOR expression, as shown in Example 2.* The supplied node must be a [[Database Module#Database Node|Database Node]]. As shown in Example 3, {{Code|update}} or {{Code|transform}} can be utilized to convert a fragment to the required internal representation.|-| '''Examples'''|'''Example 1''': The following query returns <code>{{Code|&lt;XML&gt;&lt;mark&gt;hello&lt;/mark&gt; world&lt;/XML&gt;</code>}}, if one text node of the database <code>{{Code|DB</code> }} has the value "hello world":<pre classsyntaxhighlight lang="brush:xquery">

</presyntaxhighlight>'''Example 2''': The following expression loops through the first ten full-text results and marks the results in a second expression:<syntaxhighlight lang="xquery">let $start := 1let $end := 10let $term := 'welcome'for $ft in (db:open('DB')//* [text() contains text { $term }])[position() = $start to $end]return element hit { ft:mark($ft[text() contains text { $term }])}</syntaxhighlight>'''Example 3''': The following expression returns <code>&lt;p&gt;xml>hello &lt;b&gt;word&lt;/b&gt;&lt;/pxml&gt;</code>:<pre classsyntaxhighlight lang="brush:xquery">copy $p := &lt;p&gt;word&lt;<xml>hello world</p&gt;xml>

return ft:mark($p[text() contains text 'word'], 'b')</presyntaxhighlight>

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| valign='top' width='90120' | '''Signatures'''|<code><b>{{Func|ft:extract</b>(|$nodes as node()*) as |node()*</code>}}<br /><code><b>{{Func|ft:extract</b>(|$nodes as node()*, $tag name as xs:string) as |node()*</code>}}<br /><code><b>{{Func|ft:extract</b>(|$nodes as node()*, $tag name as xs:string, $length as xs:integer) as |node()*</code>}}

| valign='top' | '''Summary'''|Extracts and returns relevant parts of full-text results. It puts a marker element around the resulting <code>{{Code|$nodes</code> }} of a full-text index request and chops irrelevant sections of the result.<br />The default tag element name of the marker element is <code>{{Code|mark</code>}}. An alternative tag element name can be chosen via the optional <code>{{Code|$tag</code> name}} argument.<br />The default length of the returned text is <code>{{Code|150</code> }} characters. An alternative length can be specified via the optional <code>{{Code|$length</code> }} argument. Note that the effective text length may differ from the specified text due to formatting and readibility issues.<br />For more details on this function, please have a look at [[#ft:mark|ft:mark]].

| valign='top' | '''Errors'''|'''[[XQuery Errors#BaseX Errors|BASX0002]]''' is raised if a referenced node is not stored in a database (i.e., references a main-memory XML fragment).<br />'''[[XQuery Errors#Functions Errors|FOCA0002]]''' is raised if <code>$name</code> is no valid QName.|-| valign='top' | '''Examples'''

* The following query may return <code>{{Code|&lt;XML&gt;...&lt;b&gt;hello&lt;/b&gt;...&lt;XML&gt;</code> }} if a text node of the database <code>{{Code|DB</code> }} contains the string "hello world":<pre classsyntaxhighlight lang="brush:xquery">

</presyntaxhighlight>

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| valign='top' width='90120' | '''Signatures'''|<code><b>{{Func|ft:count</b>(|$nodes as node()*) as |xs:integer</code>}}

| valign='top' | '''Summary'''

| valign='top' | '''Errors'''|'''[[XQuery Errors#BaseX Errors|BASX0002]]''' is raised if a referenced node is not stored in a database (i.e., references a main-memory XML fragment).|-| valign='top' | '''Examples'''

* <code>{{Code|ft:count(//*[text() contains text 'QUERY'])</code> }} returns the <code>{{Code|xs:integer</code> }} value <code>{{Code|2</code> }} if a document contains two occurrences of the string "QUERY".

 {|width='100%'

| valign='top' width='90120' | '''Signatures'''|<code><b>{{Func|ft:score</b>(|$item as item()*) as |xs:double*</code>}}

| valign='top' | '''Summary'''|Returns the score values (0.0 - 1.0) that have been attached to the specified items. <code>{{Code|0</code> }} is returned a value if no score was attached.

| valign='top' | '''Examples'''

* <code>{{Code|ft:score('a' contains text 'a')</code> }} returns the <code>{{Code|xs:double</code> }} value <code>{{Code|1</code>}}.

{|width='100%'

| valign='top' width='90120' | '''Signatures'''|{{MonoFunc|<b>ft:tokens</b>(|$db as item()) as xs:string|element(value)*}}<br/>{{MonoFunc|<b>ft:tokens</b>(|$db as item()xs:string, $prefix as xs:string) as |element(value)*}}

| valign='top' | '''Summary'''|Returns all full-text tokens stored in the index, along with their numbers of occurrences. the database {{MonoCode|$db}} may either be an <code>xs:string</code>, denoting the database name, or a node stored in the databasealong with their numbers of occurrences. <br/>If {{MonoCode|$prefix}} is specified, the returned nodes will be refined to the strings starting with that prefix. The prefix will be tokenized according to the full-text used for creating the index.

| valign='top' | '''Errors'''|'''[[XQuery {{Error|db:open|Database Module#Errors}} The addressed database does not exist or could not be opened.<br/>{{Error|db:no-index|Database Module#BaseX Errors|BASX0001]]''' is raised if }} the full-text index is not available.<br/>|-| '''[[XQuery Errors#BaseX Errors|BASX0002]]Examples''' is raised if {{Mono|Returns the number of occurrences for a single, specific index entry:<syntaxhighlight lang="xquery">let $term := ft:tokenize($term)return number(ft:tokens('db}} references a node that is not stored in a database (i.e.', references a main-memory XML fragment$term)[.= $term]/@count)<br/syntaxhighlight>'''[[XQuery Errors#BaseX Errors|BASX0003]]''' is raised if the addressed database cannot be opened.

 {|width='100%'

| valign='top' width='90120' | '''Signatures'''|{{MonoFunc|<b>ft:tokenize|$string as xs:string?|xs:string*}}<br/b>({{Func|ft:tokenize|$input string as xs:string?, $options as map(*) as ?|xs:string*}}

| valign='top' | '''Summary'''|Tokenizes the given {{MonoCode|$inputstring}} string, using the current default full-text optionsor the {{Code|$options}} specified as second argument, and returns a sequence with the tokenized string. The following options are available:* {{Code|case}}: determines how character case is processed. Allowed values are {{Code|insensitive}}, {{Code|sensitive}}, {{Code|upper}} and {{Code|lower}}. By default, search is case insensitive.* {{Code|diacritics}}: determines how diacritical characters are processed. Allowed values are {{Code|insensitive}} and {{Code|sensitive}}. By default, search is diacritical insensitive.* {{Code|stemming}}: determines is tokens are stemmed. Allowed values are {{Code|true}} and {{Code|false}}. By default, stemming is turned off.* {{Code|language}}: determines the language. This option is relevant for stemming tokens. All language codes are supported. The default language is {{Code|en}}.The {{Code|$options}} argument can be used to control full-text processing.

| valign='top' | '''Examples'''

* <code>ft:tokenize("No Doubt")</code> returns the two strings {{MonoCode|no}} and {{MonoCode|doubt}}.* <code>ft:tokenize("École", map { 'diacritics': 'sensitive' })</code> returns the string {{Code|école}}.* <code>declare ft-option using stemming; ft:tokenize("GIFTS")</code> returns a single string {{MonoCode|gift}}.|} ==ft:normalize== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|ft:normalize|$string as xs:string?|xs:string}}<br/>{{Func|ft:normalize|$string as xs:string?, $options as map(*)?|xs:string}}|-| '''Summary'''|Normalizes the given {{Code|$string}}, using the current default full-text options or the {{Code|$options}} specified as second argument. The function expects the same arguments as [[#ft:tokenize|ft:tokenize]].|-| '''Examples'''|* <code>ft:tokenize("Häuser am Meer", map { 'case': 'sensitive' })</code> returns the string {{Code|Hauser am Meer}}.|} =Errors= {| class="wikitable" width="100%"! width="110"|Code|Description|-|{{Code|options}}|Both wildcards and fuzzy search have been specified as search options.

===; Version 9.1* Updated: [[#ft:tokenize|ft:tokenize]] and [[#ft:normalize|ft:normalize]] can be called with empty sequence. ;Version 9.0 * Updated: error codes updated; errors now use the module namespace ;Version 8.0 * Added: [[#ft:contains|ft:contains]], [[#ft:normalize|ft:normalize]]* Updated: Options added to [[#ft:tokenize|ft:tokenize]] ;Version 7.8 * Added: [[#ft:contains|ft:contains]]* Updated: Options added to [[#ft:search|ft:search]] ;Version 7.1===7 * Updated: the functions no longer accept [[Database Module#Database Nodes|Database Nodes]] as reference. Instead, the name of a database must now be specified. ;Version 7.2 * Updated: [[#ft:search|ft:search]] (second argument generalized, third parameter added)

* Added: [[#ft:tokens|ft:tokens]], [[Category#ft:tokenize|ft:XQuerytokenize]]