(x)query, db lookup, and update in one step

> Hello All, > > I'm relatively new to basex and xquery - but am using basex as a large > report repository. > > I'd like to try and perform the following xquery - but with some > intermediate steps: > > xquery for $rep in collection('coll')/Report let $attr0 := $rep/@attr0 > return (replace value of node $rep/@attr1 with 'zzz') > > > The actual value represented by 'zzz' above must be based on a separate > (physical) database lookup for each attribute value $attr0 in the collection > ( i.e. the values of attr1 is a (non-trivial lookup) function of attr0. > > Is this a scenario in which multiple queries would have to be made based on > the number of documents in the collection ? > > Perhaps there is some slick way of including a call out to some method to > such that the 'zzz' above is replaced with something like: > JavaModule.doLookup($attr0) ? > > I'm executing xquery from a jruby application so either the ruby or the java > client can be used (perhaps that is somewhat irrelevant). > > Thanks in advance for any suggestions, > > Buzz > > > > > _______________________________________________ > BaseX-Talk mailing list > BaseX-Talk at mailman.uni-konstanz.de > https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk >

> Thanks Christian, > > There is (Java based) application logic including the possibility of an > RDBMS query associated with the $zzz lookup. I'll try to look through the > various references to see if it is possible to invoke that logic right in > the FLOWR expression. > > Thank you! > > Buzz > > > > On Sat, Jun 8, 2013 at 4:20 AM, Christian Grün <christian.gruen at gmail.com> > wrote: >> >> Hi Buzz, >> >> BaseX allows you to address multiple databases in one query. Your >> query could e.g. look as follows: >> >> for $rep in collection('coll')/Report >> let $attr0 := $rep/@attr0 >> let $zzz := collection('lookup')//item[@id =$attr0]/text() >> return replace value of node $rep/@attr1 with $zzz >> >> You may speed up your query a little by using db:open() instead of >> collection() (the latter one will additionally look up local files if >> there’s no database with the given name). To ensure that your query >> uses the index structures of the lookup database, you can have a look >> at the InfoView in the GUI, or turn on the query info on command line >> (-V). >> >> Hope this helps, >> Christian >> >> >> > Hello All, >> > >> > I'm relatively new to basex and xquery - but am using basex as a large >> > report repository. >> > >> > I'd like to try and perform the following xquery - but with some >> > intermediate steps: >> > >> > xquery for $rep in collection('coll')/Report let $attr0 := $rep/@attr0 >> > return (replace value of node $rep/@attr1 with 'zzz') >> > >> > >> > The actual value represented by 'zzz' above must be based on a separate >> > (physical) database lookup for each attribute value $attr0 in the >> > collection >> > ( i.e. the values of attr1 is a (non-trivial lookup) function of attr0. >> > >> > Is this a scenario in which multiple queries would have to be made based >> > on >> > the number of documents in the collection ? >> > >> > Perhaps there is some slick way of including a call out to some method >> > to >> > such that the 'zzz' above is replaced with something like: >> > JavaModule.doLookup($attr0) ? >> > >> > I'm executing xquery from a jruby application so either the ruby or the >> > java >> > client can be used (perhaps that is somewhat irrelevant). >> > >> > Thanks in advance for any suggestions, >> > >> > Buzz >> > >> > >> > >> > >> > _______________________________________________ >> > BaseX-Talk mailing list >> > BaseX-Talk at mailman.uni-konstanz.de >> > https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk >> > > >

> Hi Buzz, > > BaseX allows you to address multiple databases in one query. Your > query could e.g. look as follows: > > for $rep in collection('coll')/Report > let $attr0 := $rep/@attr0 > let $zzz := collection('lookup')//item[@id =$attr0]/text() > return replace value of node $rep/@attr1 with $zzz > > You may speed up your query a little by using db:open() instead of > collection() (the latter one will additionally look up local files if > there’s no database with the given name). To ensure that your query > uses the index structures of the lookup database, you can have a look > at the InfoView in the GUI, or turn on the query info on command line > (-V). > > Hope this helps, > Christian > > > > Hello All, > > > > I'm relatively new to basex and xquery - but am using basex as a large > > report repository. > > > > I'd like to try and perform the following xquery - but with some > > intermediate steps: > > > > xquery for $rep in collection('coll')/Report let $attr0 := $rep/@attr0 > > return (replace value of node $rep/@attr1 with 'zzz') > > > > > > The actual value represented by 'zzz' above must be based on a separate > > (physical) database lookup for each attribute value $attr0 in the > collection > > ( i.e. the values of attr1 is a (non-trivial lookup) function of attr0. > > > > Is this a scenario in which multiple queries would have to be made based > on > > the number of documents in the collection ? > > > > Perhaps there is some slick way of including a call out to some method to > > such that the 'zzz' above is replaced with something like: > > JavaModule.doLookup($attr0) ? > > > > I'm executing xquery from a jruby application so either the ruby or the > java > > client can be used (perhaps that is somewhat irrelevant). > > > > Thanks in advance for any suggestions, > > > > Buzz > > > > > > > > > > _______________________________________________ > > BaseX-Talk mailing list > > BaseX-Talk at mailman.uni-konstanz.de > > https://mailman.uni-konstanz.de/mailman/listinfo/basex-talk > > >