Hello,
I am trying to intercept an incoming SPARQL-UPDATE query string and insert some
additional statements. More precisely, I want to add some triples in the WHERE
clause.
E.g. if I have this update query coming from a user request:
DELETE {
<urn:res:dummy> a <urn:type:A> , <urn:type:b> ;
<urn:p:a> ?x .
} INSERT {
<urn:res:dummy> <urn:p:a> "hello" .
} WHERE {
?s <urn:p:a> ?x .
}
I want it to become:
DELETE {
<urn:res:dummy> a <urn:type:A> , <urn:type:b> ;
<urn:p:a> ?x .
} INSERT {
<urn:res:dummy> <urn:p:a> "hello" .
} WHERE {
<urn:res:dummy> ?p ?o .
?s <urn:p:a> ?x .
}
(I cannot control anything that is in the query so I can't just bind ?s.)
Parsing the above original query:
parseUpdate(qs)
Returns:
Update_{'prologue': [([], {})], 'request': [Modify_{'insert':
InsertClause_{'quads': Quads_{'triples':
[([rdflib.term.URIRef('urn:res:dummy'), rdflib.term.URIRef('urn:p:a'),
literal_{'string': rdflib.term.Literal('hello')}], {})]}}, 'delete':
DeleteClause_{'quads': Quads_{'triples':
[([rdflib.term.URIRef('urn:res:dummy'),
rdflib.term.URIRef('http://www.w3.org/1999/02/22-rdf-syntax-ns#type'),
rdflib.term.URIRef('urn:type:A'), rdflib.term.URIRef('urn:res:dummy'),
rdflib.term.URIRef('http://www.w3.org/1999/02/22-rdf-syntax-ns#type'),
rdflib.term.URIRef('urn:type:b'), rdflib.term.URIRef('urn:res:dummy'),
rdflib.term.URIRef('urn:p:a'), rdflib.term.Variable('x')], {})]}}, 'where':
GroupGraphPatternSub_{'part': [TriplesBlock_{'triples':
[([rdflib.term.URIRef('urn:res:dummy'), PathAlternative_{'part':
[PathSequence_{'part': [PathElt_{'part': rdflib.term.URIRef('urn:p:a')}]}]},
rdflib.term.Variable('x')], {})]}]}}]}
Precisely, where I want to add my additional triple is the very beginning of
the "request[0].where" part.
Is there a way to do this in a manner that works predictably with any possibly
complex query? I.e. without using string-based hacks, but possibly the
structure offered above, which alas, loks unfathomable to me.
Thanks,
Stefano
--
http://github.com/RDFLib
---
You received this message because you are subscribed to the Google Groups
"rdflib-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/rdflib-dev/e0f93730-fb81-4289-a5aa-a5893bb35330%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
