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RE: draft XML query results format spec

From: Seaborne, Andy <andy.seaborne@hp.com>
Date: Tue, 28 Sep 2004 18:04:46 +0100
Message-ID: <8D5B24B83C6A2E4B9E7EE5FA82627DC93967B0@sdcexcea01.emea.cpqcorp.net>
To: "Dave Beckett" <dave.beckett@bristol.ac.uk>, <public-rdf-dawg@w3.org>

Dave,

I don't mind which style of design - I would go for whatever the XML
community see as most appropriate for processing with XSLT and XQuery.

Two points from the telecon:

1/ Handling of undefined variables in individual <result>:
   Either an explicit way to say "is undefined" or
   omission of the var for that entry would work for me.

[Note the spec does not work in terms of "nulls" but in terms of "not
defined" and leaving it to the local API to decide what to do, whether
to make it appear as whatever the programming language convention is]

2/ Do XML literals go in as XML subtrees?
   I assume so - so using the same tags as the wrapper may arise and a
   poorly written XPath may (mis)match.  Not sure we can remove all
   situations of this.  Sometimes may actually want it.
   Worse case: a query result as XML literal within an XML result set.
   Example: querying a detailed server log file of queries and their
results.


FYI I checked and variable names are currently "NCNameStartChar
(NCNameChar)*" so there are no restrictions there and if we have
variables marked with ? or $, this can easily change to match the
XMLresult format.  Currently ':' is not legal in variable names to help
simple lexing but that is not fundamental.

Grammar-wise "?1" could be made legal but XML format 1 is a good enough
reason not to have it as such.

	Andy

-------- Original Message --------
> From: Dave Beckett <>
> Date: 28 September 2004 15:14
> 
> I attach two possible result formats that vary in one design choice -
>   1) variable names are element names and hence the XML is schemaless
>   2) variable names are content and the XML has a tight schema.
> 
> I presently prefer the former result1.xml since it seems more natural
> XML to use the application terms - the variable names - as element
> names.  The result XPath, XSLT etc. would read better I think.
> 
> result2.xml comes with a RelaxNG compact, RelaxNG and W3C XML Schemas
> that all validate the document.  It's got inline schemaLocation as an
> example, but that is optional if I understand WXS correctly.
> 
> Dave
Received on Tuesday, 28 September 2004 19:01:08 GMT

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