[redland-dev] xpath query

[Jagdev Bhogal]

	From the following extract we can see that AgeGroup is a descendant of GroupofPeople and GroupofPeople is a descendant of Group

	 

	<rdfs:Class rdf:about="&Content;AgeGroup"

	         rdfs:label="Content:AgeGroup">

	        <rdfs:comment>Documentation on AgeGroup(SUMO):  A GroupOfPeople whose members all have the same age or have and age which is inside a certain age interval (example, perso

	ns between 18 and 25 years)</rdfs:comment>

	        <rdfs:subClassOf rdf:resource="&Content;GroupOfPeople"/>

	</rdfs:Class>

	<rdfs:Class rdf:about="&Content;GroupOfPeople"

	         rdfs:label="Content:GroupOfPeople">

	        <rdfs:comment>Documentation on GroupOfPeople(SUMO):  Any Group whose members are exclusively Humans. The instances of this class are used for annotation of groups of inte

	rest for a certain news item. Examples of GroupOfPeople include age groups, religious groups, etc.</rdfs:comment>

	        <rdfs:subClassOf rdf:resource="&Content;Group"/>

	</rdfs:Class>

	 

	QUESTION

	How can I write the query so that it retrieves :

	a)      All childnodes of the class called Group

	b)      All parentnodes of the class called AgeGroup

	 

	Please point me in the right direction, or am I trying to achieve something that is not possible?

	Is it possible to use TURTLE within a C program to achieve the above?

	 

	Many, many thanks

	Jagdev

	 

	 

	From: Joe Andrieu [mailto:joe at switchbook.com] 
	Sent: 20 June 2010 19:05
	To: Jagdev Bhogal
	Cc: redland-dev at lists.librdf.org
	Subject: Re: [redland-dev] xpath query

	 

	I"m not sure which query module you're using, but with SPARQL, you would just get rid of the ?label term and use "City" instead.  In fact, whatever the query engine, you can probably just use sprintf or something similar to construct the query clause with "City" in place of ?label.
	
	Something like

	
	char keyword[]="City";

	char query_string[BIGENOUGHBUFFER];
	
	sprintf(query_string, "select ?comment from <C:/datafile.rdf> where (?x rdf:type rdfs:Class) (?x rdfs:label \"%s\") (?x rdfs:comment ?comment) using rdf for <http://www.w3.org/1999/02/22-rdf-syntax-ns#> <http://www.w3.org/1999/02/22-rdf-syntax-ns> , rdfs for <http://www.w3.org/2000/01/rdf-schema#> <http://www.w3.org/2000/01/rdf-schema> ", keyword);

	I won't address the potential unicode and buffer overrun problems. I prefer c++ classes to deal with the buffer issues and haven't yet settled completely on how I'm handling unicode.
	
	-j
	
	
	

	Joe Andrieu
	joe at switchbook.com
	+1 (805) 705-8651
	http://www.switchbook.com <http://www.switchbook.com/> 

	
	On 6/20/2010 4:11 AM, Jagdev Bhogal wrote: 

	Dear all

	I have a c-program which currently parses an rdf file and retrieves all of the nodes using:

	 

	const char *query_string="select ?label, ?comment from <C:/datafile.rdf> where (?x rdf:type rdfs:Class) (?x rdfs:label ?label) (?x rdfs:comment ?comment) using rdf for <http://www.w3.org/1999/02/22-rdf-syntax-ns#>,rdfs <http://www.w3.org/1999/02/22-rdf-syntax-ns#%3E,rdfs>  for <http://www.w3.org/2000/01/rdf-schema#>";

	Lets say I have a string defined as:

	 

	char keyword[]="City";

	 

	My question is can we have a where clause in the query, so that we only retrieve results where the strcmp(label, keyword) = 0 in other words only retrieve those results where the label is equal to the keyword which in this case is "City". 

	 

	If further explanation is needed let me know.

	Thank you

	Jagdev

	 

	 

	 

	 

	 

	 

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________________________________

	Through our significant contribution to the creative industries and the city's cultural and artistic life,
	Birmingham City University is proud to support Birmingham's bid to be UK City of Culture in 2013
	
	http://birminghamculture.org <http://birminghamculture.org/> 
	http://www.bcu.ac.uk/about-us/excellent-arts 



Through our significant contribution to the creative industries and the city's cultural and artistic life,
Birmingham City University is proud to support Birmingham's bid to be UK City of Culture in 2013

http://birminghamculture.org
http://www.bcu.ac.uk/about-us/excellent-arts
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