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=Conventions=
{{Mark|Updated with Version 9.0:}} All functions and errors in this module are assigned to the <code><nowiki>http://basex.org/modules/xquery</nowiki></code> namespace, which is statically bound to the {{Code|xquery}} prefix.<br/>All errors are assigned to the <code><nowiki>http://basex.org/errors</nowiki></code> namespace, which is statically bound to the {{Code|bxerr}} prefix.
=Functions=
==xquery:eval==
{{Mark|Updated with Version 89.50:}} <{{code>base-uri</code> |pass}} option added.
{| width='100%'
|-
| width='120' | '''Signatures'''
|{{Func|xquery:eval|$query as xs:string|item()*}}<br />{{Func|xquery:eval|$query as xs:string, $bindings as map(*)?|item()*}}<br />{{Func|xquery:eval|$query as xs:string, $bindings as map(*)?, $options as map(xs:string, xs:string*)?|item()*}}<br />
|-
| '''Summary'''
* {{Code|permission}}: the query will be evaluated with the specified permissions (see [[User Management]]).
* {{Code|timeout}}: query execution will be interrupted after the specified number of seconds.
* {{Code|memory}}: query execution will be interrupted if the specified number of megabytes will be exceeded. This check works best if only one process is running at the same time. Moreover, please note that this option enforces garbage collection, so it will take some additional time, and it requires GC to be enabled in your JVM.* {{Code|base-uri}}: set [https://www.w3.org/TR/xquery-31/#dt-static-base-uri base-uri property] for the query. This URI will be used when resolving relative URIs by functions such as {{Code|fn:doc}}. Added with * {{VersionCode|8pass}}: passes on the original error info (line and column number, optional file uri).5By default, this option is {{Code|false}}.
|-
| '''Errors'''
|{{Error|BXXQ0001update|#Errors}} the query contains [[XQuery Update#Updating Expressions|updating expressions]].<br/>{{Error|BXXQ0003permission|#Errors}} insufficient permissions for evaluating the query.<br/>{{Error|BXXQ0004timeout|#Errors}} query execution exceeded timeout or .<br/>{{Error|limit|#Errors}} query execution exceeded memory limit.<br/>{{Error|FOTY0013nested|#Errors}} the expression yields function itemsnested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the query.
|-
| '''Examples'''
|}
==xquery:eval-update== {{Mark|Updated with Version 9.0:}} Renamed (old name: xquery:update) {| width='100%'|-| width='120' | '''Signatures'''|{{Func|xquery:eval-update|$query as xs:string|item()*}}<br />{{Func|xquery:eval-update|$query as xs:string, $bindings as map(*)?|item()*}}<br />{{Func|xquery:eval-update|$query as xs:string, $bindings as map(*)?, $options as map(*)?|item()}}<br />|-| '''Summary'''|Evaluates {{Code|$query}} as updating XQuery expression at runtime.<br/>All updates will be added to the [[XQuery Update#Pending Update List|Pending Update List]] of the main query and performed after the evaluation of the main query.<br />The rules of the {{Code|$bindings}} and {{Code|$options}} parameters are the same as for [[#xquery:eval|xquery:eval]].|-| '''Errors'''|{{Error|update|#Errors}} the query contains no [[XQuery Update#Updating Expressions|updating expressions]].<br/>{{Error|permission|#Errors}} insufficient permissions for evaluating the query.<br/>{{Error|timeout|#Errors}} query execution exceeded timeout.<br/>{{Error|limit|#Errors}} query execution exceeded memory limit.<br/>{{Error|nested|#Errors}} nested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the query.|} ==xquery:invoke== {| width='100%'|-| width='120' | '''Signatures'''|{{Func|xquery:invoke|$uri as xs:string|item()*}}<br />{{Func|xquery:invoke|$uri as xs:string, $bindings as map(*)?|item()*}}<br />{{Func|xquery:invoke|$uri as xs:string, $bindings as map(*)?, $options as map(*)?|item()*}}<br />|-| '''Summary'''|Evaluates the XQuery module located at {{Code|$uri}} at runtime and returns the resulting items. A relative URI will be resolved against the static base URI of the query.<br />The rules of the {{Code|$bindings}} and {{Code|$options}} parameters are the same as for [[#xquery:eval|xquery:eval]].|-| '''Errors'''|{{Error|update|#Errors}} the expression contains [[XQuery Update#Updating Expressions|updating expressions]].<br/>{{Error|permission|#Errors}} insufficient permissions for evaluating the query.<br/>{{Error|timeout|#Errors}} query execution exceeded timeout.<br/>{{Error|nested|#Errors}} nested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the query.|} ==xquery:invoke-update==
{| width='100%'
|-
| width='120' | '''Signatures'''
|{{Func|xquery:invoke-update|$query uri as xs:string|item()*}}<br />{{Func|xquery:invoke-update|$query uri as xs:string, $bindings as map(*)?|item()*}}<br />{{Func|xquery:invoke-update|$query uri as xs:string, $bindings as map(*)?, $options as map(xs:string, xs:string*)?|item()*}}<br />
|-
| '''Summary'''
|Evaluates the updating XQuery module located at {{Code|$queryuri}} as updating XQuery expression at runtime.<br/>All updates A relative URI will be added to the [[XQuery Update#Pending Update List|Pending Update List]] of the main query and performed after resolved against the evaluation static base URI of the main query.<br />The semantics rules of the {{Code|$bindings}} and {{Code|$options}} parameters is are the same as for [[#xquery:eval|xquery:eval]].
|-
| '''Errors'''
|{{Error|BXXQ0002update|#Errors}} the query expression contains no [[XQuery Update#Updating Expressions|updating expressions]].<br/>{{Error|BXXQ0003permission|#Errors}} insufficient permissions for evaluating the query.<br/>{{Error|BXXQ0004timeout|#Errors}} query execution exceeded timeout or memory limit.<br/>{{Error|FOTY0013nested|#Errors}} the expression yields function itemsnested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the query.
|}
==xquery:parse==
 
{{Mark|Updated with Version 9.0:}} {{code|base-uri}} option added.
{| width='100%'
|-
| width='120' | '''Signatures'''
|{{Func|xquery:parse|$query as xs:string|item()*?}}<br />{{Func|xquery:parse|$query as xs:string, $options as map(*)?|item()?}}<br />
|-
| '''Summary'''
* {{Code|plan}}: returns an XML representation of the internal query plan. By default, this option is {{Code|true}}. The naming of the expressions in the query plan may change over time
* {{Code|pass}}: passes on the original error info (line and column number, optional file uri). By default, this option is {{Code|false}}.
* {{Code|base-uri}}: set [https://www.w3.org/TR/xquery-31/#dt-static-base-uri base-uri property] for the query. This URI will be used when resolving relative URIs by functions such as {{Code|fn:doc}}.
|-
| '''Errors'''
==xquery:parse-uri==
 
{{Mark|Updated with Version 9.0:}} {{code|base-uri}} option added.
{| width='100%'
|-
| width='120' | '''Signatures'''
|{{Func|xquery:parse-uri|$uri as xs:string|item()*?}}<br />{{Func|xquery:parse-uri|$uri as xs:string, $options as map(*)?|item()*?}}<br />
|-
| '''Summary'''
|Parses the XQuery module located at {{Code|$uri}} and returns the resulting query plan. A relative URI will be resolved against the static base URI of the query. The rules for the {{Code|$options}} parameter is are the same as for [[#xquery:parse|xquery:parse]].
|-
| '''Errors'''
|}
=Parallelized Execution= Parallel query execution is recommendable if you have various calls that require a lot of time, but cannot be sped up by rewriting the code. This is e. g. the case if external URLs are called. If you are parallelizing local data reads (such as the access to a database), single-threaded queries will usually be faster, because parallelized access to disk data often results in randomized access patterns, which can hardly be optimized by the caching strategies of HD, SSD or operating system. ==xquery:invokefork-join==
{| width='100%'
|-
| width='120' | '''Signatures'''
|{{Func|xquery:invokefork-join|$uri functions as xs:string|itemfunction()*}}<br />{{Func|xquery:invoke|$uri as xs:string, $bindings as map(*)|item()*}}<br />{{Func|xquery:invoke|$uri as xs:string, $bindings as map(*), $options as map(*)|item()*}}<br />
|-
| '''Summary'''|Evaluates This function executes the XQuery module located at {{Code|$uri}} at runtime and returns the resulting items. Database nodes supplied (non-updating) functions in the result will be copied and returned instead.<br />The semantics of the {{Code|$bindings}} and {{Code|$options}} parameters is the same as for [[#xquery:eval|xquery:eval]]parallel.
|-
| '''ErrorsExamples'''|{{Error|BXXQ0001|#Errors}} the expression contains [[XQuery Update#Updating Expressions|updating expressions]].* The following function sleeps in parallel; it will be finished in 1 second if your system has at least 2 cores:<br/pre class='brush:xquery'>let $f := function() {{Error|BXXQ0003|#Errorsprof:sleep(1000) }} insufficient permissions for evaluating the query.return xquery:fork-join(($f, $f))<br/pre>{{Error|BXXQ0004|#Errors}} query execution exceeded timeout.<br/>{{Error|FOTY0013|#Errors}} the expression yields function items.<br/>Any other error that may occur while evaluating * In the following query.|}, up to four URLs will be requested in parallel:<pre class=='brush:xquery'>let $funcs :type== for $segment in 1 to 4{| width let $url :='100%http://url.com/path'|-| width='120' | '''Signatures'''$segment| return function() {{Func|xqueryhttp:type|send-request((), $expr as item(url)*|item}return xquery:fork-join($funcs)*}}</pre>
|-
| '''SummaryErrors'''|Similar to {{CodeError|fn:trace($expr, $msg)error|#Errors}}, but instead of a user-defined message, it emits the compile-time type and estimated result size of its argumentan unexpected error occurred.
|}
=Errors=
 
{{Mark|Updated with Version 9.0:}}
{| class="wikitable" width="100%"
|Description
|-
|{{Code|BXXQ0001permission}}|The specified Insufficient permissions for evaluating the query contains [[XQuery Update#Updating Expressions|updating expressions]].
|-
|{{Code|BXXQ0002update}}|The specified query contains no [[XQuery Update#Updating Expressions|updating expressionsexpression]]found or expected.
|-
|{{Code|BXXQ0003timeout}}|Insufficient permissions for evaluating the Query execution exceeded timeout.|-|{{Code|memory}}|Query execution exceeded memory limit.|-|{{Code|nested}}|Nested queryevaluation is not allowed.
|-
|{{Code|BXXQ0004error}}|Query execution exceeded timeout or memory limitAn unexpected error occurred.
|}
=Changelog=
 
;Version 9.0
 
* Added: [[#xquery:invoke-update|xquery:invoke-update]]
* Updated: [[#xquery:eval|xquery:eval]]: {{Code|pass}} option added
* Updated: [[#xquery:parse|xquery:parse]], [[#xquery:parse-uri|xquery:parse-uri]]: {{Code|base-uri}} option added
* Updated: xquery:update renamed to [[#xquery:eval-update|xquery:eval-update]]
* Updated: error codes updated; errors now use the module namespace
;Version 8.5
 
* Added: [[#xquery:fork-join|xquery:fork-join]]
* Updated: [[#xquery:eval|xquery:eval]]: {{Code|base-uri}} option added
* Updated: Relative URIs will always be resolved against the static base URI of the query
* Deleted: xquery:type (moved to [[Profiling Module]]
;Version 8.4
 
* Added: [[#xquery:parse-uri|xquery:parse-uri]]
* Updated: [[#xquery:parse|xquery:parse]]: {{Code|pass}} option added
;Version 8.0
 * Added: [[#xquery:update|xquery:update]], [[#xquery:parse|xquery:parse]]
* Deleted: [[#xquery:evaluate|xquery:evaluate]] (opened databases will now be closed by main query)
;Version 7.8.2
 
* Added: {{Code|$options}} argument
;Version 7.8
 
* Added: [[#xquery:evaluate|xquery:evaluate]]
* Updated: used variables must be explicitly declared in the query string.
This module was introduced with Version 7.3. Functions have been adopted from the obsolete Utility Module.
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