Strange behavior while adding existing elements into new element.

On Tue, Jun 20, 2017 at 8:09 PM, Jan Dölle <basex-list at id1.de> wrote: > Hi, > > just before you asking me. No we wasn't to isolate the Problem for now. > > Working on a complex transaction with database involved, we get the > following phenomenon. > > declare function m:paths($el as element()) > as xs:string* > { > distinct-values( > for $e in $item/descendant::* > return > string-join($e/ancestor-or-self::*/local-name(.), "/") > ) > }; > > This function should produce a list of paths to all child of $el. And it > works! > > But sometimes we get some strange results. We created new element > constructed from others, may existing, elements. > > let $sequence-of-elements := collect-some-elements($from-somewhere) > let $new-element := element el { $sequence-of-elements } > return paths($new-element) > > Most of the time we get as expected results like: > > el/c1 > el/c1/c12 > el/c2 > el/c2/c21 > el/c2/c22 > el/.. > > But sometimes it looks like that parents of the copied elements are not set > correctly: > > oldParentOfc1/c1 > oldParentOfc1/c1/c12 > otherOld/ParentOfc2/c2 > otherOld/ParentOfc2/c2/c21 > otherOld/ParentOfc2/c2/c22 > ... > > If we do a copy of the result <el> like parse-xml(serialize($new-element))/* > and call paths() again, everything looks now as expected. > > We call the function what products such results, isolated within a > test-script with exact the same inputs. But suddenly the result was correct. > > Then we copied the inputs of the function within the integration (parse-xml, > serialize). But it failed again. > > Also notable is, that the "bad result" is stable. It produces always the > same result on same inputs (no random). > > So we have no idea to isolate the issue. > > Any suggestions? > > Best Regards > > Jan > > -- > > Jan Dölle > E-Mail: basex-list at id1.de Telefon +49-69-244502-0 Home: www.id1.de > > Information Design One AG, Baseler Straße 10, 60329 Frankfurt am Main > Registereintrag: Amtsgericht Frankfurt am Main, HRB 52596 > Vorstand: Robert Peters, Aufsichtsrat: Christian Hecht (Vorsitz) > >

Am 20.06.2017 um 20:21 schrieb Christian Grün: > Hi Jan, > > This reminds me of an open GitHub issue [1], but it’s just a guess. > > Does your query work as expected if you append "update { }" to your > newly constructed element? > > let $new-element := element el { > $sequence-of-elements } update { } > > In BaseX, there are two different types of nodes: fragment nodes > (which are created by XQuery node constructors) and database nodes > (which are compact representations of XML trees). In your example, the > $sequence-of-elements (which, I guess, is a sequence of database > nodes) will be wrapped with an element constructor. By using "update > {}", your node will be copied and transformed to a database node. See > [2] for some more details on the update keyword. > > Quite obviously this is just a workaround to test how your query > behaves. If it behaves correctly, I am pretty sure that [1] would need > to be fixed to get your query running correctly. > > Cheers, > Christian > > [1] https://github.com/BaseXdb/basex/issues/919 > [2] http://docs.basex.org/wiki/Update#update > > > On Tue, Jun 20, 2017 at 8:09 PM, Jan Dölle <basex-list at id1.de> wrote: >> Hi, >> >> just before you asking me. No we wasn't to isolate the Problem for now. >> >> Working on a complex transaction with database involved, we get the >> following phenomenon. >> >> declare function m:paths($el as element()) >> as xs:string* >> { >> distinct-values( >> for $e in $item/descendant::* >> return >> string-join($e/ancestor-or-self::*/local-name(.), "/") >> ) >> }; >> >> This function should produce a list of paths to all child of $el. And it >> works! >> >> But sometimes we get some strange results. We created new element >> constructed from others, may existing, elements. >> >> let $sequence-of-elements := collect-some-elements($from-somewhere) >> let $new-element := element el { $sequence-of-elements } >> return paths($new-element) >> >> Most of the time we get as expected results like: >> >> el/c1 >> el/c1/c12 >> el/c2 >> el/c2/c21 >> el/c2/c22 >> el/.. >> >> But sometimes it looks like that parents of the copied elements are not set >> correctly: >> >> oldParentOfc1/c1 >> oldParentOfc1/c1/c12 >> otherOld/ParentOfc2/c2 >> otherOld/ParentOfc2/c2/c21 >> otherOld/ParentOfc2/c2/c22 >> ... >> >> If we do a copy of the result <el> like parse-xml(serialize($new-element))/* >> and call paths() again, everything looks now as expected. >> >> We call the function what products such results, isolated within a >> test-script with exact the same inputs. But suddenly the result was correct. >> >> Then we copied the inputs of the function within the integration (parse-xml, >> serialize). But it failed again. >> >> Also notable is, that the "bad result" is stable. It produces always the >> same result on same inputs (no random). >> >> So we have no idea to isolate the issue. >> >> Any suggestions? >> >> Best Regards >> >> Jan >> >> -- >> >> Jan Dölle >> E-Mail: basex-list at id1.de Telefon +49-69-244502-0 Home: www.id1.de >> >> Information Design One AG, Baseler Straße 10, 60329 Frankfurt am Main >> Registereintrag: Amtsgericht Frankfurt am Main, HRB 52596 >> Vorstand: Robert Peters, Aufsichtsrat: Christian Hecht (Vorsitz) >> >>