Finding element in XML database with certain attribute value in xQuery -

i facing following problem statement:

for each administrative unit co-administered 2 or more other administrative units, verify that:

• it refers these co-administrative units using administeredby association role.
• each of these co-administrative units refers mentioned co-administered unit using coadminister association role.

the database looks follows:

<?xml version "1.0" ?> <wfs:featurecollection xmlns:au="http://inspire.ec.europa.eu/schemas/au/4.0" xmlns:gts="http://www.isotc211.org/2005/gts" xmlns:gco="http://www.isotc211.org/2005/gco" xmlns:ns1="http://www.w3.org/1999/xhtml" xmlns:hfp="http://www.w3.org/2001/xmlschema-hasfacetandproperty" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:gn="http://inspire.ec.europa.eu/schemas/gn/4.0" xmlns:gss="http://www.isotc211.org/2005/gss" xmlns:gsr="http://www.isotc211.org/2005/gsr" xmlns:base="http://inspire.ec.europa.eu/schemas/base/3.3" xmlns:gmd="http://www.isotc211.org/2005/gmd" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" xmlns:wfs="http://www.opengis.net/wfs/2.0" xsi:schemalocation="http://inspire.ec.europa.eu/schemas/au/4.0 http://inspire.ec.europa.eu/schemas/au/4.0/administrativeunits.xsd http://www.opengis.net/wfs/2.0 http://schemas.opengis.net/wfs/2.0/wfs.xsd" numbermatched="274" numberreturned="274" timestamp="2016-03-29t18:12:51.630+02:00"> <wfs:member>     <au:administrativeunit gml:id="nc.mt01402">         <au:administeredby xlink:href="#nc.mt01310"/>         <au:administeredby xlink:href="#nc.mt01407"/>         <au:coadminister nilreason="unpopulated"/>     </au:administrativeunit> </wfs:member> <wfs:member>     <au:administrativeunit gml:id="nc.mt01310">         <au:administeredby nilreason="unpopulated" xsi:nil="true"/>         <au:coadminister xlink:href="#nc.mt01402"/>     </au:administrativeunit> </wfs:member> <wfs:member>     <au:administrativeunit gml:id="nc.mt01407">         <au:upperlevelunit xlink:href="#nc.mt0xxxx"/>         <au:administeredby nilreason="unpopulated" xsi:nil="true"/>         <au:coadminister xlink:href="#nc.mt01402"/>      </au:administrativeunit> </wfs:member> </wfs:featurecollection> 

i have written following xquery expression:

let $administrativeunits := $features[self::*:administrativeunit]  let $featureswitherrors :=     (for $candidate in $administrativeunits         let $administeredby := $candidate/au:administeredby/@xlink:href         let $candidateval := string($candidate/@gml:id)      return        if (count($administeredby) >= 2) (           let $coadmincheck :=             (for $administer in $administeredby                 let $administerval := string($administer)                 let $coadminval := $administrativeunits/au:administrativeunit[@gml:id = $administerval]/au:coadminister/@xlink:href                 return                     if (string($coadminval) = $candidateval) () else $administer             )              return                  if ($coadmincheck) $candidate else ()        )                else ()   )[position() le $limiterrors] return (if ($featureswitherrors) 'failed' else 'passed',   local:error-statistics('tr.featureswitherrors', count($featureswitherrors)),  $feature in $featureswitherrors    order $feature/@gml:id    return local:addmessage('tr.nocoadministered', map { 'filename': local:filename($feature), 'featuretype': local-name($feature), 'gmlid': string($feature/@gml:id), 'adminby' : string($feature/au:administeredby[1]/@xlink:href) }))  

i getting 'failed' result, if shouldn't be.

i believe problem lies in statement:

let $coadminval := $administrativeunits/au:administrativeunit[@gml:id = $administerval]/au:coadminister/@xlink:href 

as $coadminval seems empty.

i have tried several other ways write statement, turn out wrong:

let $coadminval := $administrativeunits/au:administrativeunit[matches(@gml:id, $administerval)]/au:coadminister/@xlink:href let $coadminval := $administrativeunits/au:administrativeunit[contains(@gml:id, $administerval)]/au:coadminister/@xlink:href let $coadminval := $administrativeunits/au:administrativeunit[string(@gml:id) = $administerval]/au:coadminister/@xlink:href 

what correct way this?

i agree, looks problem lies in comparison expression in predicate:

[@gml:id = $administerval] 

since $administerval au:administeredby/@xlink:href attribute, let's @ you're comparing:

gml:id="nc.mt01402" xlink:href="#nc.mt01310" xlink:href="#nc.mt01407" 

the difference @xlink:href values prepended # sign. account this, change comparison to:

[@gml:id = substring-after($administerval, "#")] 

your other approach of using contains() failed because asking if value nc.mt01402 contained #nc.mt01402. reversing parameters work.

the same applies matches() - although aware function takes regular expressions patterns, characters . match character rather literal period character. force search literal period character, need escape it, e.g., matches("#nc.mt01402", "nc\.mt01402").

given additional complexities of matches() (unless want pattern matching rather literal comparisons), i'd trimming $administerval substring() or using contains() best approach.