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(unknown charset) Re: why query languages and RDF data have syntaxes?

From: (unknown charset) Libby Miller <Libby.Miller@bristol.ac.uk>
Date: Fri, 29 Nov 2002 10:48:44 +0000 (GMT)
To: (unknown charset) JeffZhang <jeffzhang726@yahoo.com.cn>
cc: (unknown charset) "www-rdf-interest@w3.org" <www-rdf-interest@w3.org>
Message-ID: <Pine.GSO.4.44.0211291036180.26043-100000@mail.ilrt.bris.ac.uk>


Personally, I implemented a query language for RDF because I was doing
the same kind of api calls over and over again. I was writing JSPs and
servlets. I didn't want to have to hand code RDF in XML (or RDF by an
API) to create queries. SQL-like query languages like SquishQL, RDFdb's
query language RDQL and Algae, query the RDF model but with a relatively
simple, familiar, SQL-like syntax. The connection with SQL is purely
syntactic; the query is basically a subgraph with bits missing.

If you were automating the generation of queries, then RDF/XML would
probably be ok, but for humans to create (and read), an SQL-like syntax
is easier. Building a query from API calls negates the point of the
convenience of a query language.

cheers

Libby

On Fri, 29 Nov 2002, JeffZhang wrote:

>
> Dear all,
>     I can not understand why syntaxes of several current rdf query languages are so much different
> with the syntax of RDF data. In my opinion, a query is match a pattern(a subgraph with
> undetermined values) against the universal(the big graph in knowledge base). Why not use
> just a small rdf data set with blank nodes to represent the subgraph?
> I think these query languages have more close relation with sql than with rdf model.
>
>
>
> Best regards,
>
>
> JeffZhang
> jeffzhang726@yahoo.com.cn
> 2002-11-29
>
>
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Received on Friday, 29 November 2002 05:51:08 GMT

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