Changes

All functions in this module are assigned to the {{Code|<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|<code><nowiki>http://basex.org/errors}} </nowiki></code> namespace, which is statically bound to the {{Code|bxerr}} prefix.

|{{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 itemmap(xs:string, xs:string)|item()*}}<br />

|Evaluates the supplied {{Code|$query}} string as XQuery expression at runtime and returns the resulting items.<br/>The evaluated query has its own query context. If a returned node is stored in a database, a main-memory copy will be returned as result, because the referenced database is closed after query execution and will not be accessible anymore.<br />Variables and context items can be declared via {{Code|$bindings}}. The specified keys must be QNames or strings, the values can be arbitrary item sequences:* variables specified as QNames If a key is a QName, it will be directly interpreted adopted as variable name.* variables specified as xs:It a key is a string , it may be prefixed with a dollar sign. Namespace can be specified using the [http://www.jclark.com/xml/xmlns.htm Clark Notation].

The {{Code|$options}} parameter contains evaluation options, which can either be specified* as children of an {{Code|<xquery:options/>}} element:<pre class="brush:xml"><xquery:options> <xquery:permission value="none"/></xquery:options></pre>* as map, which contains all key/value pairs:<pre class="brush:xml">map { "permission": "none" }</pre>The following options are available:

* {{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}}.

|{{Error|BXXQ0001|#Errors}} the query contains [[XQuery Update#Updating Expressions|updating expressions]].<br/>{{Error|BXXQ0003|#Errors}} insufficient permissions for evaluating the query.<br/>{{Error|BXXQ0004|#Errors}} query execution exceeded timeout or memory constraintslimit.<br/>{{Error|FOTY0013BXXQ0005|#Errors}} nested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the expression yields function itemsquery.

{| width='100%'|-| width='120' | '''Signatures'''|{{MarkFunc|xquery:update|$query as xs:string|Added with Version 8item()*}}<br />{{Func|xquery:update|$query as xs:string, $bindings as map(*)?|item()*}}<br />{{Func|xquery:update|$query as xs:string, $bindings as map(*)?, $options as map(xs:string, xs:string)|item()}}<br />|-| '''Summary'''|Evaluates {{Code|$query}} as updating XQuery expression at runtime.0<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|BXXQ0002|#Errors}} the query contains no [[XQuery Update#Updating Expressions|updating expressions]].<br/>{{Error|BXXQ0003|#Errors}} insufficient permissions for evaluating the query.<br/>{{Error|BXXQ0004|#Errors}} query execution exceeded timeout or memory limit.<br/>{{Error|BXXQ0005|#Errors}}nested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the query.|} ==xquery:parse==

|{{Func|xquery:updateparse|$query as xs:string|item()*}}<br />{{Func|xquery:updateparse|$query as xs:string, $bindings options as map(*)|item()*}}<br />{{Func|xquery:update|$query as xs:string, $bindings as map(*), $options as item()|item()}}<br />

|Evaluates Parses the specified {{Code|$query}} string as updating XQuery expression at runtimemodule and returns the resulting query plan.<br/>All updates will be added to The {{Code|$options}} parameter influences the [[XQuery Update#Pending Update Listoutput:* {{Code|Pending Update List]] of compile}}: additionally compiles the main query and performed after parsing it. By default, this option is {{Code|false}}.* {{Code|plan}}: returns an XML representation of the evaluation internal query plan. By default, this option is {{Code|true}}. The naming of the main expressions in the queryplan 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}}.

|Any error that may occur while parsing the query.|-| '''Examples'''|* {{ErrorCode|BXXQ0002|#Errorsxquery:parse("1 + 3")}} the query contains no [[XQuery Update#Updating Expressions|returns:<pre class='brush:xml'><MainModule updating expressions]].="false"> <QueryPlan compiled="false"> <Arith op="+"> <Int value="1" type="xs:integer"/> <Int value="3" type="xs:integer"/> </Arith> </QueryPlan></MainModule><br/pre>|} ==xquery:parse-uri== {| width='100%'|-| width='120' | '''Signatures'''|{Error{Func|xquery:parse-uri|BXXQ0003$uri as xs:string|#Errorsitem()*}} insufficient permissions for evaluating the query.<br/>{{ErrorFunc|xquery:parse-uri|BXXQ0004$uri as xs:string, $options as map(*)|#Errorsitem()*}} query execution exceeded timeout or memory constraints.<br/>|-| '''Summary'''|Parses the XQuery module located at {{ErrorCode|FOTY0013$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 are the same as for [[#xquery:parse|xquery:parse]].|-| '''Errors}} '''|Any error that may occur while parsing the expression yields function itemsquery.

|{{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 itemmap(*)|item()*}}<br />

|Opens Evaluates the XQuery module located at {{Code|$uri}} as file, evaluates it as XQuery expression at runtime, and returns the resulting items. Database nodes in the result A relative URI will be copied and returned insteadresolved against the static base URI of the query.<br />The semantics rules of the {{Code|$bindings}} and {{Code|$options}} parameters is are the same as for [[#xquery:eval|xquery:eval]].

|{{Error|BXXQ0001|#Errors}} the expression contains [[XQuery Update#Updating Expressions|updating expressions]].<br/>{{Error|BXXQ0003|#Errors}} insufficient permissions for evaluating the query.<br/>{{Error|BXXQ0004|#Errors}} query execution exceeded timeout.<br/>{{Error|FOTY0013BXXQ0005|#Errors}} nested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the expression yields function itemsquery.

=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:typefork-join==

|{{Func|xquery:typefork-join|$expr functions as itemfunction(*)*|item()*}}|-|'''Summary'''|This function executes the supplied (non-updating) functions in parallel.|-| '''Examples'''|* The following function sleeps in parallel; it will be finished in 1 second if your system has at least 2 cores:<pre class='brush:xquery'>let $f := function() { prof:sleep(1000) }return xquery:fork-join(($f, $f))</pre>* In the following query, up to four URLs will be requested in parallel:<pre class='brush:xquery'>let $funcs := for $segment in 1 to 4 let $url := 'http://url.com/path' || $segment return function() { http:send-request((), $url) }return xquery:fork-join($funcs)</pre>

| '''SummaryErrors'''|Similar to {{CodeError|fn:trace($expr, $msg)BXXQ0006|#Errors}}, but instead of a user-defined message, it emits the compile-time type and estimated result size of its argumentan unexpected error occurred.

|Query execution exceeded timeoutor memory limit.|-|{{Code|BXXQ0005}}|Nested query evaluation is not allowed.|-|{{Code|BXXQ0006}}|An unexpected error occurred.

* Added: [[#xquery:update|xquery:update]], [[#xquery:parse|xquery:parse]]