Changes

This [[Module Library|XQuery Module]] contains functions for parsing and evaluating XQuery strings and modules at runtime, and to run code in parallel.

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.

=FunctionsDynamic Evaluation=

|{{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 />

|{{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|BXXQ0005nested|#Errors}} nested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the query.

==xquery:eval-update==

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

|{{Error|BXXQ0002update|#Errors}} the query 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 .<br/>{{Error|limit|#Errors}} query execution exceeded memory limit.<br/>{{Error|BXXQ0005nested|#Errors}} nested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the query.

|{{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 />

|{{Error|BXXQ0001update|#Errors}} the expression 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.<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|$uri as xs:string|item()*}}<br />{{Func|xquery:invoke-update|$uri as xs:string, $bindings as map(*)?|item()*}}<br />{{Func|xquery:invoke-update|$uri as xs:string, $bindings as map(*)?, $options as map(*)?|item()*}}<br />|-| '''Summary'''|Evaluates the updating XQuery module located at {{Code|$uri}} at runtime. 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 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|BXXQ0005nested|#Errors}} nested query evaluation is not allowed.<br/>Any other error that may occur while evaluating the query.

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

|{{Func|xquery:parse-uri|$uri as xs:string|item()?}}<br />{{Func|xquery:parse-uri|$uri as xs:string, $options as map(*)?|item()?}}<br />

Parallel query execution is recommendable if you have various calls that require a lot of time, but that 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 will rarely be optimized by the caching strategies of HDHDDs, SSDs, SSD or the operating system.

let $funcs xquery:=fork-join(

let $url := 'http://url.com/path/' || $segment

return xquery:fork-join($funcs)

|{{Error|BXXQ0006error|#Errors}} an unexpected error occurred.

|{{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 queryQuery execution exceeded timeout.

|{{Code|BXXQ0004memory}}|Query execution exceeded timeout or memory limit.

|{{Code|BXXQ0005nested}}

|{{Code|BXXQ0006error}}

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