Limit number of results in xquery

Question

I have the following Xquery code:

for $w in $words
let $freq := (count($corpus[. eq $w]) div count($content2[text() eq $w])) 
order by $freq descending
return <tr><td>{$w}</td><td>{$freq}</td></tr>

$words is some distinct words that appears (may appear multiple times) in $corpus. $content2 is some another bag of words. Variables and division is not that important.

This xquery lists some frequency calculation of words, ordered.

What I want to do is limit the results by 10. I tried to use positional values but as it gives me the position of the word in the word list, it didnt work out..

Any help?

Answer 1

The number of results can e.g. be limited as follows:

(for $w in $words
 let $freq := (count($corpus[. eq $w]) div count($content2[text() eq $w])) 
 order by $freq descending
 return <tr><td>{$w}</td><td>{$freq}</td></tr>
)[position() = 1 to 10]

Answer 2

Use subsequence($sequence, $start, $records) to return a subset of results, starting at record $start (be aware XQuery counts from 1) returning records items. Have a look at "Limiting Result Sets" XQuery Wikibooks Page. An example of how to apply the function copied from this page:

let $sorted-people :=
   for $person in collection($collection)/person
   order by $person/last-name/text()
   return $person

for $person at $count in subsequence($sorted-people, $start, $records)
return
   <li>{ $person/last-name/text() }</li>