[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: node identity in XQuery

• To: takeha-e <takeha-e@i...>, xml-dev@l...
• Subject: Re: node identity in XQuery
• From: Jonathan Robie <jonathan.robie@s...>
• Date: Sat, 23 Mar 2002 07:52:06 -0500
• In-reply-to: <20020323.133918.92544224.takeha-e@i...>

At 01:39 PM 3/23/2002 +0900, takeha-e wrote:

>Hi.
>
>I tried some XQuery implementations(Kawa, MS XQuery Demo).
>But, node identity function (==, !==) has not been implemented yet.

It is implemented in Software AG's QuiP. Here's a query that uses it:

let $a := <foo/>
let $b := <foo/>
return
   <out>
     <one>$a == $a</one>
     <two>$a == $b</two>
   </out>

Here are the results:

   <out>
     <one>$a == $a</one>
     <two>$a == $b</two>
   </out>


>Is it difficult to implement node identity in XQuery data model?

That depends a lot on the underlying implementation. If nodes in the system 
used to implement it have identity, you simply use the identity of those 
nodes. If not, you need to impose identity.

>I think we need unique node identifiers for all nodes in large XML
>Repository.
>And, it's difficult to identify all nodes efficiently if there happened
>update of XML Repository.

I agree.

Jonathan

• Follow-Ups:
  • Re: node identity in XQuery
    • From: Michael Dyck <michaeldyck@s...>

• References:
  • node identity in XQuery
    • From: takeha-e <takeha-e@i...>

• Prev by Date: Formal specifications (was: Who can implement W3C XML Schema ?)
• Next by Date: Re: Re: Training
• Previous by thread: node identity in XQuery
• Next by thread: Re: node identity in XQuery
• Index(es):
  • Date
  • Thread