- From: Michael Kay <mhk@mhk.me.uk>
- Date: Sat, 10 Dec 2005 00:15:59 -0000
- To: "'Sergio Andreozzi'" <sergio.andreozzi@cnaf.infn.it>, <www-ql@w3.org>
I assume you've got the answer you wanted over on talk@xquery.com, which is
proving a rather more useful forum for such questions.
Michael Kay
> -----Original Message-----
> From: www-ql-request@w3.org [mailto:www-ql-request@w3.org] On
> Behalf Of Sergio Andreozzi
> Sent: 07 December 2005 16:40
> To: www-ql@w3.org
> Subject: grouping by closest ancestor
>
>
> Dear all,
>
> I'm facing a problem in XQuery/XPath. I would like to ask you for some
> advice. Please, consider the following XML document:
>
> <?xml version="1.0" encoding="UTF-8"?>
> <S>
> <A>
> <B>
> <F>4</F>
> <C>
> <D>3</D>
> <E>5</E>
> <G>
> <H>3</H>
> </G>
> <G>
> <H>2</H>
> </G>
> </C>
> </B>
> <B>
> <F>2</F>
> <C>
> <E>2</E>
> <G>
> <H>5</H>
> </G>
> <G>
> <H>4</H>
> </G>
> </C>
> <C>
> <D>7</D>
> <E>2</E>
> </C>
> </B>
> </A>
> <A>
> <B>
> <F>3</F>
> <C>
> <D>3</D>
> <E>2</E>
> </C>
> <C>
> <D>5</D>
> <E>2</E>
> </C>
> </B>
> </A>
> <A>
> <B>
> <F>2</F>
> <C>
> <D>5</D>
> <E>2</E>
> </C>
> </B>
> </A>
> </S>
>
> given a for clause like this: for $A in doc ("doc.xml")/S/A
> as an example, I would like to work on the result of the
> following XPath
> expressions:
>
> $A/B/F ...
> $A/B/C/D ...
> $A/B/C/E ...
> $A/B/C/G/H ...
>
> but I need to have the results reorganized in such a way that I can
> create groups based on the closest common ancestor (per each pair of
> elements) as follows:
>
> first A element, the XPath queries return:
>
> $A/B/F = (4,2)
> $A/B/C/D = (3,7)
> $A/B/C/E = (5,2,2)
> $A/B/C/G/H = (3,2,5,4)
>
> a possible refatctoring of the result is ( _ can be replaced with 0 ):
>
> $A/B/F = (4,4,2,2,2)
> $A/B/C/D = (3,3,_,_,7)
> $A/B/C/E = (5,5,5,5,2)
> $A/B/C/G/H = (3,2,5,4,_)
>
> In this result, considering each column, every pair of values
> refers to
> the elements which have the closest ancestor (among all the elements
> with the same QName part of the XPath sequence result). For instance:
>
> col 1, row 1: F=4
> col 1, row 4: H=3
>
> they have the first B element as closest ancestor. Conversely, in the
> generated result, I don't have H=3 coupled with F=2 as they have A as
> closest ancestor. A is farer than the common ancestor between H=3 and
> F=4 (the first B).
>
> The idea is to generate all the possible tuples (read by column in my
> proposal), one value for each element, but valid tuples are
> those which
> have the closest ancestor (considering elements in pair).
> Missing values
> can be filled with 0.
>
> In the remaining part you can find refactoring of the result for the
> other A elements:
>
> first A element, the XPath queries return:
>
> $A/B/F = (3)
> $A/B/C/D = (3,5)
> $A/B/C/E = (2,2)
>
> I would like something like this:
>
> $A/B/F = (3,3)
> $A/B/C/D = (3,5)
> $A/B/C/E = (2,2)
>
> first A element, the XPath queries return:
>
> $A/B/F = (2)
> $A/B/C/D = (5)
> $A/B/C/E = (2)
>
> that's fine.
>
> I would appreciate any suggestion or guidelines on how to generate the
> results constrained as explained above. I hope that the problem
> description is enough clear, otherwise I can provide more details.
>
> Regards, Sergio
>
>
>
Received on Saturday, 10 December 2005 00:16:36 UTC