[xquery-talk] Looping in Xquery

[John Snelson]

You're close - the missing part is that you want to use the sum() 
function, ie:

<short-desc>{
   sum(
     for $shrtdesc in $ltnfiles//subtopic[@id = 'DEF']//short-definition
     return string-length($shrtdesc/p/text)
   )
}</short-desc>

John

On 04/09/12 10:15, Mailing Lists Mail wrote:
> Dear Xquery Adults,
>
> I am very new here.. I have some issues with getting my requirements
> working.. I guess, this should be very simple, but dont seem to get my
> heads around... THe following is what I want..
>
> I have loads of XMLs in the Data Store ( markLogic)
>
> I have to run a query to do the return the string lengths of certain
> elements from 100 XMLs./
>
> So my pseudo code will be :
>
> <results>
> For all XMLs in the Data store
> {
>
>     <file filename = "filename of the current file ">
>
>            <desc> {length of desc at //xx/y/desc }
>      <!--
>     There could be more than one desc, in which case, i would like the
> sum of all the string lengths of each desc
> -->
>   </desc>
>
> <short-desc>
> {
>     string-length ( //xx//yy/short-desc)
> }
>
> </short-desc>
>
>    </file>
>
> </results>
>
>
> My attempts:
>
>
>   declare namespace dict = "http://www.lexis-nexis.com/glp/dict";
> for $ltnfiles in doc()
>    let $NAME:= document-uri($ltnfiles)
> return (
>   <ltn  >
>    <name>
>     {$NAME}
>    </name>
>     <short-desc>
>     {string-length(string($ltnfiles//subtopic[@id =
> 'DEF']/short-definition/p/text))}
>     </short-desc>
>   </ltn>
> )
> THe above works fine, if there is only one short-definition.. FOr more
> than one shortdefiitions, it comes up with the error message obviously
> because the string does not allow 2 arguments, while the stuff passed
> into the function is a sequence...
>
> How do I do another loop inside the first one, for each short-defiitin
> ... SOmething like :
>
> for $ltnfiles in doc()
>    let $NAME:= document-uri($ltnfiles)
> return (
>   <ltn  >
>    <name>
>     {$NAME}
>    </name>
>     {
>     for $shrtdesc in $ltnfiles//subtopic[@id = 'DEF']//short-definition
>     <short-desc>
>     {
>     string-length( $shrtdesc/p/text)
>     }
>     </short-desc>
>      }
>   </ltn>
> )
>   DOEstNT WORK .. :( This wont give me what I want as What I want is a
> sum (string-lengths of all the short-def) .. But atleast i thought i
> would get something like
>
> <short-desc>100</short-desc>
> <short-desc>344</short-desc>
>
> ( I would have liked <short-desc>444</short-desc> )
>
> ANy help would be highly appreciated ..
>
> Thanks
>
> Dak.
>
>


-- 
John Snelson, Lead Engineer                    http://twitter.com/jpcs
MarkLogic Corporation                         http://www.marklogic.com