the key isn't to try to aggregate, it's to use sequences and qualified
XPaths in XQuery. so how about:
<speakers>
{
let $speech := doc("speeches.xml")//speech
let $speakers := distinct-values($speech/speaker)
for $speaker in $speakers
order by $speaker
return
<speaker>
<name>{$speaker}</name>
<count>{ count($speech[speaker = $speaker]/line) }</count>
</speaker>
}
</speakers>
i haven't actually tested it, but it seems about right to me. i might
have missed a / in the $speech predicate in the count().
ian
________________________________
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Eric
Caplain
Sent: Thursday, March 13, 2008 7:54 PM
To: [email protected]
Subject: [MarkLogic Dev General] how to implement an accumulator
I've some XML like:
<speech>
<speaker>Joe</speaker>
<line>blah blah blah</line>
...
<line>this that and the other thing</line>
</speech>
I can get each speaker and then get each speech of that speaker
and a count of lines in each speech, but I haven't been able to get the
total count of all lines by a speaker.
In the following, the function line-count returns the count of
lines in each speech, but I need to accumulate these counts and return
that, and I haven't been able to figure out a way to do that. Any
suggestions would be appreciated.
define function line-count($s as xs:string) as xs:integer {
let $count := 0
for $_speech in doc("speeches.xml")//speech
where some $_speaker in $_speech/speeker
satisfies ($_speaker/text() = $s)
return count($_speech/line)
}
<speakers>
{
let $speech := doc("speeches.xml")//speech
for $speaker in distinct-values($speech/speaker)
order by $speaker
return
<speaker>
<name>{$speaker}</name>
<count>{ line-count($speaker) }</count>
</speaker>
}
</speakers>
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