Re: Review of Primer, part 2 (of N)

Danny Ayers wrote:
>
> The SPARQL was a little problematic, the best version I could come up
> with (with much assistance from AndyS) is below. Couple more minor
> editorial points early on. I got rather blocked on this, hopefully the
> rest of the doc won't take as long...
>
> *** Scheduling a Meeting
> s/showin/shown in
done
> *** Referencing via Profile
>
> http://purl.org/NET/erdf/extract-rdf
> =>
> http://purl.org/NET/erdf/extract-rdf.xsl
> (appears in text & code)
done, needs to double-check to make sure it still works. I assume it was
previously done via media-types, if that still works I will remove
".xsl" since I think it's better practice to use media-types.
> -
>
> "Then Jane's queries can be run on the merged calendars"
>
> Just before this line, something like:
> "Because of the RDF model, this kind of data can be merged by simply
> adding it to an RDF store, or a SPARQL query may be run across the
> data sources after transformation to RDF."
done, but we can't talk about SPARQL before introducing it.  So changed
to:  'One of the advantages of the RDF data model is that RDF data can
be easily merged by adding it to a RDF store, so Jane can merge and
query all the calendars together once they are transformed into RDF. 
Jane uses
SPARQL <a href="#SPARQL">[SPARQL]</a> to query her data, which
automatically merges the calendar data sources before running the query.
SPARQL (The SPARQL Protocol and RDF Query Language) is a query language
for RDF with a syntax similar to well-known data-base query languages.'
> -
>
> PREFIX ical: <http://www.w3.org/2002/12/cal/icaltzd#>
>
> SELECT ?start1 ?stop1 ?loc1 ?summ1
>
> FROM <http://www.w3.org/2001/sw/grddl-wg/doc29/david-erdf.rdf>
> FROM <http://www.w3.org/2001/sw/grddl-wg/doc29/robin-hcal-grddl.rdf>
> FROM <http://www.w3.org/2001/sw/grddl-wg/doc29/janeschedule.rdf>
>
> WHERE
>  {
>        ?event1 a ical:Vevent;
>              ical:summary ?summ1;
>              ical:dtstart ?start1 ;
>              ical:dtend ?stop1 ;
>              ical:location ?loc1.
>        ?event2 a ical:Vevent;
>              ical:summary ?summ2 ;
>              ical:dtstart ?start2;
>              ical:dtend ?stop2;
>              ical:location ?loc2.
>        ?event3 a ical:Vevent;
>              ical:summary ?summ3 ;
>              ical:dtstart ?start3;
>              ical:dtend ?stop3;
>              ical:location ?loc3.
>
>      FILTER ( str(?start1) = str(?start2) ).
>      FILTER ( str(?stop1) = str(?stop2) ).
>      FILTER ( str(?loc1) = str(?loc2) ).
>      FILTER ( str(?start1) = str(?start3) ).
>      FILTER ( str(?stop1) = str(?stop3) ).
>      FILTER ( str(?loc1) = str(?loc3) ).
>      FILTER ( str(?start3) = str(?start2) ).
>      FILTER ( str(?stop3) = str(?stop2) ).
>      FILTER ( str(?loc3) = str(?loc2) ).
>
>      FILTER ( ?event1 != ?event2 &&  ?event2 != ?event3  &&  ?event1
> != ?event3  ).
>      FILTER ( str(?summ1) < str(?summ2) && str(?summ2) < str(?summ3) ) .
> }
done.
> explanatory text needed, maybe:
> [[
> The SELECT line determines which variable will appear in the results,
> here one of the start dates, one of the stop dates, a location and a
> summary. The FROM lines identify the data sources to use in the query,
> in this case the RDF/XML derived from Jane, David and Robin's original
> documents. The WHERE section provides a pattern which can match three
> events. The first block of FILTERs match up identical start and stop
> dates as well as locations between the three events. These values,
> which may be differently typed, are simplified to simple literals with
> the str() operator. The final two FILTER lines are idiomatic
> expressions which prevent multiple resultsreturning due to the
> interchangeability of the variables.
> ]]
done.
> results (using ARQ) are actually:
>
> start1  stop1   loc1  summ1
> | "2007-01-08"^^xs:date | "2007-01-11"^^xs:date | "Edinburgh,
> UK"^^<http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral> | "Web
> Conference"^^<http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral> |
>
> probably best to present as:
>
> start1  stop1   loc1  summ1
> "2007-01-08" "2007-01-11"  "Edinburgh, UK"  "Web Conference"
>
>
seems to be the way it's already presented in Primer.

-- 
  -harry

Harry Halpin,  University of Edinburgh 
http://www.ibiblio.org/hhalpin 6B522426

Received on Tuesday, 26 June 2007 03:32:25 UTC