[xquery-talk] Function and Query Evaluation with No XML Tags Error

[Wei, Alice J.]

Hi, David:

  I think I am having a different issue different from what I had several weeks ago.
   What I have modified is from:

let $ad := fn:collection("xmldb:exist://db/cbml")//ad/p[contains(upper-case(.), 'BOOK')]
let $sorted_result:=
for $doc in distinct-values($ad)
order by $doc
return $doc
for $r at $count in $sorted_result
let $nodes := $ad[. = $r][1]
return
<ad>
{$nodes}
</ad>

  by trying to put it in user-defined functions, which is currently giving me quite a bit of problems from itself.

declare boundary-space preserve;
declare function local:distinct(
     $seq as xs:anyAtomicType*)
      as xs:anyAtomicType
 {
 let $doc := distinct-values($seq)
 order by $doc
 return
  <ad>{$doc} </ad>
 };

 for $ad in
distinct-values(collection("xmldb:exist://db/cbml")//ad/p[contains(upper-case(.$
 return
<ad>{local:distinct($ad)}</ad>

As I mentioned before, I only intend to have the output be appeared in the same way as the above XQuery that is not in the function.
Is this possible?

Thanks for your help.
======================================================
Alice Wei
MIS 2008
School of Library and Information Science
Indiana University Bloomington
ajwei at indiana.edu
________________________________________
From: David Carlisle [davidc at nag.co.uk]
Sent: Tuesday, February 26, 2008 10:33 AM
To: Wei, Alice J.
Cc: talk at x-query.com
Subject: Re: [xquery-talk] Function and Query Evaluation with No XML Tags Error

Alice,

Alice it seems hard to help as you have been essentially posting the
same code, with the same error for weeks,

When you go

 for $ad in distinct-values(...anything)

then, on each iteration $ad will be a single string (one of the values)

So on each call to local:distinct($ad) you are passing in a single string. so
doing operations such as distinct-values() or for or order by are all
essentialy null-operations. It's not an error to take all the
unique values from a sequence of length one and then sort them, but you will always
just get back the value you started with.


See for example:

http://x-query.com/pipermail/talk/2008-January/002436.html

David

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