Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Hello, Speaking about horsepower on Linked data, this could be a project to follow : http://linkeddatafragments.org/ Cheers, Nicola Vitucci nicola.vitu...@gmail.com a écrit : Hi all, sorry for the late answer. First of all, thanks for the encouraging comments! In order to track suggestions and bugs more easily I've created a Github repo here: https://github.com/nvitucci/wikisparql-project I'll try and write up stuff as things progress, but feel free to start using the issue tracker. @Paul: You can generally run those O.K. on the DBpedia SPARQL endpoint. It would be nice to see a few more horsepower put behind this. You're definitely right. Speaking of pure horsepower the machine hosting WikiSPARQL is not that big right now (32 GB of RAM, 8-thread CPU, no SSDs), but there are a couple things I'd like to do from the backend side in order to try and improve this kind of queries. @Markus: By the way, if you can control the output UI completely, you may consider adding this: instead of a property or item URI, always display its label (in a selected language), and merely show the URI as a tooltip or similar. This could be done after querying with Javascript so that people don't need to do many join+filter parts in queries just to retrieve the labels. Showing a (localized) label in place of a URI is a neat idea, I planned to do that but my main concern is for when you get a lot of URIs as a result of your query, because this might add some overhead - to be tried though. P.S. Your interface is very nice, but as Paul remarked it seems that some of the queries are a little slow. Could you maybe rewire the SPARQL execution to our endpoint at http://milenio.dcc.uchile.cl/sparql? It seems to be faster. Of course, I understand if you want to use it for your own testing, but if your main interest is in the UI and not the backend, this might be a nice cooperation. I decided to spend some time on the UI because it makes the use of the endpoint easier, but my main goal is to try and understand together with the community what can be done to make the use of an endpoint as efficient as possible, not only by tuning the right parameters (e.g. should there be a timeout on the queries? how much RAM should I make available? etc.) but even by looking at different technologies. It's great though to have a chance to compare results with other endpoints, and it might be a good idea to give a chance to decide which endpoint(s) to use as you suggested, thus I can see many chances for cooperation. By the way, can I reuse your queries as example queries? @Kingsley: SPARQL URLs should work across SPARQL endpoints. Basically, you should only change the host part of the URL to execute the same query across different endpoints. Indeed, that would be pretty easy, provided that SPARQL variants (e.g. the use of parentheses around aggregate expressions, or magic properties) are handled correctly. Cheers, Nicola ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.orghttps://lists.wikimedia.org/mailman/listinfo/wikidata-l Jean-Baptiste Pressac Traitement et analyse de bases de données Centre de Recherche Bretonne et Celtique 20 rue Duquesne CS 93837 29238 BREST cedex 3 tel : +33 (0)2 98 01 68 95 fax : +33 (0)2 98 01 63 93 ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
This is a great development!
I managed to run some simple queries, but I am having trouble with
profiling-type queries such as
select
?p (count(*) as ?cnt)
{ ?s ?p ?o}
group by ?p
order by desc(?cnt)
You can generally run those O.K. on the DBpedia SPARQL endpoint. It would
be nice to see a few more horsepower put behind this.
On Wed, Apr 8, 2015 at 7:11 PM, Nicola Vitucci nicola.vitu...@gmail.com
wrote:
Il 08/04/2015 23:43, Markus Krötzsch ha scritto:
On 08.04.2015 17:24, Nicola Vitucci wrote:
Il 08/04/2015 16:36, Markus Krötzsch ha scritto:
On 08.04.2015 15:07, Nicola Vitucci wrote:
Hi Markus,
would you recommend to add some sort of patch until the new dumps
are
out, either in the data (by adding some triples to a temporary
graph) or
just in the Web interface for the external links?
If you need it ASAP, you could actually just implement it in our Java
code and make a pull request. It should not be too much effort. You can
use the issue to ask about details if you are not sure what to do.
Otherwise the ETA would be end of April/beginning of May (several other
RDF extensions are currently being worked on and will happen first,
e.g., ranks in RDF).
I don't need it right now, so given the short ETA I'd wait. Anyway, in
order to let people use external links more easily, I could just
manually drop the last letter (or apply any other rule) only in the
href links for now, while leaving the URIs intact. Do you see any harm
in this?
Ah, you mean for dispayling links in HTML? No, there is no harm in this
at all. Most likely, the final life exports will also redirect to the
property entity exports (which would make most sense for LOD crawlers).
Indeed. I made this temporary change on WikiSPARQL, so that links like
in Jean-Baptiste's examples may work properly. If you try this:
http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/Q18335803%3E
and then click on the external link on any property, now you should be
redirected to the right wiki page.
Nicola
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*Applying Schemas for Natural Language Processing, Distributed Systems,
Classification and Text Mining and Data Lakes*
(607) 539 6254paul.houle on Skype ontolo...@gmail.com
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http://legalentityidentifier.info/lei/lookup
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Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
On 09.04.2015 01:11, Nicola Vitucci wrote:
...
Indeed. I made this temporary change on WikiSPARQL, so that links like
in Jean-Baptiste's examples may work properly. If you try this:
http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/Q18335803%3E
and then click on the external link on any property, now you should be
redirected to the right wiki page.
Nice, here is a query to make good use of this:
All properties used on Wikidata to connect too humans, ordered by the
number of times that they are used in this way
http://wikisparql.org/sparql?query=PREFIX+%3A+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2F%3E%0D%0ASELECT+DISTINCT+%3Fproperty+%28COUNT%28DISTINCT+%3Fperson1%29+as+%3FpersonCount%29%0D%0AWHERE+{%0D%0A+++%3Fperson1+a+%3AQ5+.%0D%0A+++%3Fperson2+a+%3AQ5+.%0D%0A+++%3Fperson1+%3Fproperty+%3Fperson2+%0D%0A}+ORDER+BY+DESC%28%3FpersonCount%29
Most of the properties with less than, say, 5 uses are probably errors
(one could do other queries to find out which humans have this
particular connection).
As soon as we have the explicit links to the property entities, it will
also be possible to create the (more useful) list of property labels.
By the way, if you can control the output UI completely, you may
consider adding this: instead of a property or item URI, always display
its label (in a selected language), and merely show the URI as a tooltip
or similar. This could be done after querying with Javascript so that
people don't need to do many join+filter parts in queries just to
retrieve the labels.
Markus
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Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
P.S. Your interface is very nice, but as Paul remarked it seems that
some of the queries are a little slow. Could you maybe rewire the SPARQL
execution to our endpoint at http://milenio.dcc.uchile.cl/sparql? It
seems to be faster. Of course, I understand if you want to use it for
your own testing, but if your main interest is in the UI and not the
backend, this might be a nice cooperation.
Cheers,
Markus
On 09.04.2015 22:16, Markus Krötzsch wrote:
On 09.04.2015 01:11, Nicola Vitucci wrote:
...
Indeed. I made this temporary change on WikiSPARQL, so that links like
in Jean-Baptiste's examples may work properly. If you try this:
http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/Q18335803%3E
and then click on the external link on any property, now you should be
redirected to the right wiki page.
Nice, here is a query to make good use of this:
All properties used on Wikidata to connect too humans, ordered by the
number of times that they are used in this way
http://wikisparql.org/sparql?query=PREFIX+%3A+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2F%3E%0D%0ASELECT+DISTINCT+%3Fproperty+%28COUNT%28DISTINCT+%3Fperson1%29+as+%3FpersonCount%29%0D%0AWHERE+{%0D%0A+++%3Fperson1+a+%3AQ5+.%0D%0A+++%3Fperson2+a+%3AQ5+.%0D%0A+++%3Fperson1+%3Fproperty+%3Fperson2+%0D%0A}+ORDER+BY+DESC%28%3FpersonCount%29
Most of the properties with less than, say, 5 uses are probably errors
(one could do other queries to find out which humans have this
particular connection).
As soon as we have the explicit links to the property entities, it will
also be possible to create the (more useful) list of property labels.
By the way, if you can control the output UI completely, you may
consider adding this: instead of a property or item URI, always display
its label (in a selected language), and merely show the URI as a tooltip
or similar. This could be done after querying with Javascript so that
people don't need to do many join+filter parts in queries just to
retrieve the labels.
Markus
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Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
On 08.04.2015 17:24, Nicola Vitucci wrote: Il 08/04/2015 16:36, Markus Krötzsch ha scritto: On 08.04.2015 15:07, Nicola Vitucci wrote: Hi Markus, would you recommend to add some sort of patch until the new dumps are out, either in the data (by adding some triples to a temporary graph) or just in the Web interface for the external links? If you need it ASAP, you could actually just implement it in our Java code and make a pull request. It should not be too much effort. You can use the issue to ask about details if you are not sure what to do. Otherwise the ETA would be end of April/beginning of May (several other RDF extensions are currently being worked on and will happen first, e.g., ranks in RDF). I don't need it right now, so given the short ETA I'd wait. Anyway, in order to let people use external links more easily, I could just manually drop the last letter (or apply any other rule) only in the href links for now, while leaving the URIs intact. Do you see any harm in this? Ah, you mean for dispayling links in HTML? No, there is no harm in this at all. Most likely, the final life exports will also redirect to the property entity exports (which would make most sense for LOD crawlers). Markus ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Il 08/04/2015 23:43, Markus Krötzsch ha scritto: On 08.04.2015 17:24, Nicola Vitucci wrote: Il 08/04/2015 16:36, Markus Krötzsch ha scritto: On 08.04.2015 15:07, Nicola Vitucci wrote: Hi Markus, would you recommend to add some sort of patch until the new dumps are out, either in the data (by adding some triples to a temporary graph) or just in the Web interface for the external links? If you need it ASAP, you could actually just implement it in our Java code and make a pull request. It should not be too much effort. You can use the issue to ask about details if you are not sure what to do. Otherwise the ETA would be end of April/beginning of May (several other RDF extensions are currently being worked on and will happen first, e.g., ranks in RDF). I don't need it right now, so given the short ETA I'd wait. Anyway, in order to let people use external links more easily, I could just manually drop the last letter (or apply any other rule) only in the href links for now, while leaving the URIs intact. Do you see any harm in this? Ah, you mean for dispayling links in HTML? No, there is no harm in this at all. Most likely, the final life exports will also redirect to the property entity exports (which would make most sense for LOD crawlers). Indeed. I made this temporary change on WikiSPARQL, so that links like in Jean-Baptiste's examples may work properly. If you try this: http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/Q18335803%3E and then click on the external link on any property, now you should be redirected to the right wiki page. Nicola ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Hello, Thank you for this initiative. However, there is a little problem with the Properties on the result pages. For instance on the result page of this query http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/Q18335803%3E all Wikidata properties have an extra letter after the property ID, for instance P463 https://www.wikidata.org/wiki/Property:P463 has an extra s (P463s) so that the link to this property (on the arrow icon) leads to a bad request page. A click on this link : http://www.wikidata.org/entity/P463s Brings you on this page rather than http://www.wikidata.org/entity/P463. There is also a problem with the link to the wikidata ontology on this page http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/VTe085defe2fad71c9445145ec538e724c%3E. For instance time precision has a link to http://www.wikidata.org/ontology#timePrecision which does not exists. Cheers, Jean-Baptiste Pressac Traitement et analyse de bases de données Production et diffusion de corpus numériques Centre de Recherche Bretonne et Celtique Unité mixte de service (UMS) 3554 20 rue Duquesne CS 93837 29238 Brest cedex 3 tel : +33 (0)2 98 01 68 95 fax : +33 (0)2 98 01 63 93 Le 23/03/2015 12:51, Marco Fossati a écrit : Hi everyone, I'd just like to announce another experimental Wikidata SPARQL endpoint [1], kindly provided by the folks at SpazioDati [2]. It contains both the simplified and the complete dumps, as per [3]. Each dump file is stored under a different named graph. We are collecting the query logs, and will share the most frequent queries. Cheers! [1] http://wikisparql.org/ [2] http://spaziodati.eu/en/ [3] http://tools.wmflabs.org/wikidata-exports/rdf/exports/20150223/ On 3/21/15 1:00 PM, wikidata-l-requ...@lists.wikimedia.org wrote: On 3/20/15 2:08 PM, Markus Kroetzsch wrote: Dear all, Thanks to the people at the Center of Semantic Web Research in Chile [1], we have a very first public SPARQL endpoint for Wikidata running. This is very preliminary, so do not rely on it in applications and expect things to fail, but you may still enjoy some things. http://milenio.dcc.uchile.cl/sparql You have a SPARQL that provides access to Wikidata dumps loaded into an RDF compliant RDBMS (in this case a Virtuoso RDBMS instance). I emphasis a because the first isn't accurate. There are other endpoints that provide access to Wikidata dumps: [1]http://lod.openlinksw.com/sparql -- 61 Billion+ RDF triples culled from across the LOD Cloud (if you lookup Wikidata URIs that are objects of owl:sameAs relations you'll end up in Wikidata own Linked Data Space) [2]http://wikidata.metaphacts.com/sparql -- another endpoint I discovered yesterday . attachment: Jean-Baptiste_Pressac.vcf___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
2015-03-23 16:37 GMT+01:00 Markus Krötzsch mar...@semantic-mediawiki.org: Brilliant, we should set up a page with a list of SPARQL endpoits for Wikidata! For production usage, it is great to have a variety to chose from. strong +1 Also, would you mind if the examples you shared on this list are reused on the other projects? I specifically have in mind to use them to provide example queries on Wikidata-LDF?[1] Thank you, Cristian [1] http://wikidataldf.com/ ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
On 4/8/15 6:14 AM, Cristian Consonni wrote: 2015-03-23 16:37 GMT+01:00 Markus Krötzschmar...@semantic-mediawiki.org: Brilliant, we should set up a page with a list of SPARQL endpoits for Wikidata! For production usage, it is great to have a variety to chose from. strong +1 Also, would you mind if the examples you shared on this list are reused on the other projects? I specifically have in mind to use them to provide example queries on Wikidata-LDF?[1] Thank you, Cristian [1]http://wikidataldf.com/ See: http://www.wikidata.org/wiki/Wikidata:Data_access re., current SPARQL Endpoint list. -- Regards, Kingsley Idehen Founder CEO OpenLink Software Company Web: http://www.openlinksw.com Personal Weblog 1: http://kidehen.blogspot.com Personal Weblog 2: http://www.openlinksw.com/blog/~kidehen Twitter Profile: https://twitter.com/kidehen Google+ Profile: https://plus.google.com/+KingsleyIdehen/about LinkedIn Profile: http://www.linkedin.com/in/kidehen Personal WebID: http://kingsley.idehen.net/dataspace/person/kidehen#this smime.p7s Description: S/MIME Cryptographic Signature ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Hi Jean-Baptiste, Your observation is correct. This is because a single Wikidata statement (with one Wikidata property) does not translate into a single triple (with one RDF property) in RDF. Rather, several RDF triples are used, they need to use more than one property, and these properties have different declarations (e.g., some are DatatypeProperties and some are ObjectProperties). Therefore, we create property variants, currently by appending letters like s. The current RDF encoding is documented in our ISWC 2014 paper: https://ddll.inf.tu-dresden.de/web/Inproceedings4005/en You are still right that there is a problem here in that you cannot get from P123s to P123 in the current RDF. This is being worked on: https://github.com/Wikidata/Wikidata-Toolkit/issues/84 The dumps will hopefully have this soon. Regards, Markus On 08.04.2015 12:05, Jean-Baptiste Pressac wrote: Hello, Thank you for this initiative. However, there is a little problem with the Properties on the result pages. For instance on the result page of this query http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/Q18335803%3E all Wikidata properties have an extra letter after the property ID, for instance P463 https://www.wikidata.org/wiki/Property:P463 has an extra s (P463s) so that the link to this property (on the arrow icon) leads to a bad request page. A click on this link : http://www.wikidata.org/entity/P463s Brings you on this page rather than http://www.wikidata.org/entity/P463. There is also a problem with the link to the wikidata ontology on this page http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/VTe085defe2fad71c9445145ec538e724c%3E. For instance time precision has a link to http://www.wikidata.org/ontology#timePrecision which does not exists. Cheers, Jean-Baptiste Pressac Traitement et analyse de bases de données Production et diffusion de corpus numériques Centre de Recherche Bretonne et Celtique Unité mixte de service (UMS) 3554 20 rue Duquesne CS 93837 29238 Brest cedex 3 tel : +33 (0)2 98 01 68 95 fax : +33 (0)2 98 01 63 93 Le 23/03/2015 12:51, Marco Fossati a écrit : Hi everyone, I'd just like to announce another experimental Wikidata SPARQL endpoint [1], kindly provided by the folks at SpazioDati [2]. It contains both the simplified and the complete dumps, as per [3]. Each dump file is stored under a different named graph. We are collecting the query logs, and will share the most frequent queries. Cheers! [1] http://wikisparql.org/ [2] http://spaziodati.eu/en/ [3] http://tools.wmflabs.org/wikidata-exports/rdf/exports/20150223/ On 3/21/15 1:00 PM, wikidata-l-requ...@lists.wikimedia.org wrote: On 3/20/15 2:08 PM, Markus Kroetzsch wrote: Dear all, Thanks to the people at the Center of Semantic Web Research in Chile [1], we have a very first public SPARQL endpoint for Wikidata running. This is very preliminary, so do not rely on it in applications and expect things to fail, but you may still enjoy some things. http://milenio.dcc.uchile.cl/sparql You have a SPARQL that provides access to Wikidata dumps loaded into an RDF compliant RDBMS (in this case a Virtuoso RDBMS instance). I emphasis a because the first isn't accurate. There are other endpoints that provide access to Wikidata dumps: [1]http://lod.openlinksw.com/sparql -- 61 Billion+ RDF triples culled from across the LOD Cloud (if you lookup Wikidata URIs that are objects of owl:sameAs relations you'll end up in Wikidata own Linked Data Space) [2]http://wikidata.metaphacts.com/sparql -- another endpoint I discovered yesterday . ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Thank you, I will have a look to your publication to have a better understanding of the mecanism of RDFisation. Are you also going to solve the problem with the links to the wikidata ontology ? For instance on this page http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/VTe085defe2fad71c9445145ec538e724c%3E time precision has a link to http://www.wikidata.org/ontology#timePrecision which does not exists. Regards, Jean-Baptiste Pressac Traitement et analyse de bases de données Production et diffusion de corpus numériques Centre de Recherche Bretonne et Celtique Unité mixte de service (UMS) 3554 20 rue Duquesne CS 93837 29238 Brest cedex 3 tel : +33 (0)2 98 01 68 95 fax : +33 (0)2 98 01 63 93 Le 08/04/2015 15:07, Nicola Vitucci a écrit : Hi Markus, would you recommend to add some sort of patch until the new dumps are out, either in the data (by adding some triples to a temporary graph) or just in the Web interface for the external links? Cheers, Nicola (wikisparql.org) Il 08/04/2015 14:49, Markus Krötzsch ha scritto: Hi Jean-Baptiste, Your observation is correct. This is because a single Wikidata statement (with one Wikidata property) does not translate into a single triple (with one RDF property) in RDF. Rather, several RDF triples are used, they need to use more than one property, and these properties have different declarations (e.g., some are DatatypeProperties and some are ObjectProperties). Therefore, we create property variants, currently by appending letters like s. The current RDF encoding is documented in our ISWC 2014 paper: https://ddll.inf.tu-dresden.de/web/Inproceedings4005/en You are still right that there is a problem here in that you cannot get from P123s to P123 in the current RDF. This is being worked on: https://github.com/Wikidata/Wikidata-Toolkit/issues/84 The dumps will hopefully have this soon. Regards, Markus On 08.04.2015 12:05, Jean-Baptiste Pressac wrote: Hello, Thank you for this initiative. However, there is a little problem with the Properties on the result pages. For instance on the result page of this query http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/Q18335803%3E all Wikidata properties have an extra letter after the property ID, for instance P463 https://www.wikidata.org/wiki/Property:P463 has an extra s (P463s) so that the link to this property (on the arrow icon) leads to a bad request page. A click on this link : http://www.wikidata.org/entity/P463s Brings you on this page rather than http://www.wikidata.org/entity/P463. There is also a problem with the link to the wikidata ontology on this page http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/VTe085defe2fad71c9445145ec538e724c%3E. For instance time precision has a link to http://www.wikidata.org/ontology#timePrecision which does not exists. Cheers, Jean-Baptiste Pressac Traitement et analyse de bases de données Production et diffusion de corpus numériques Centre de Recherche Bretonne et Celtique Unité mixte de service (UMS) 3554 20 rue Duquesne CS 93837 29238 Brest cedex 3 tel : +33 (0)2 98 01 68 95 fax : +33 (0)2 98 01 63 93 Le 23/03/2015 12:51, Marco Fossati a écrit : Hi everyone, I'd just like to announce another experimental Wikidata SPARQL endpoint [1], kindly provided by the folks at SpazioDati [2]. It contains both the simplified and the complete dumps, as per [3]. Each dump file is stored under a different named graph. We are collecting the query logs, and will share the most frequent queries. Cheers! [1] http://wikisparql.org/ [2] http://spaziodati.eu/en/ [3] http://tools.wmflabs.org/wikidata-exports/rdf/exports/20150223/ On 3/21/15 1:00 PM, wikidata-l-requ...@lists.wikimedia.org wrote: On 3/20/15 2:08 PM, Markus Kroetzsch wrote: Dear all, Thanks to the people at the Center of Semantic Web Research in Chile [1], we have a very first public SPARQL endpoint for Wikidata running. This is very preliminary, so do not rely on it in applications and expect things to fail, but you may still enjoy some things. http://milenio.dcc.uchile.cl/sparql You have a SPARQL that provides access to Wikidata dumps loaded into an RDF compliant RDBMS (in this case a Virtuoso RDBMS instance). I emphasis a because the first isn't accurate. There are other endpoints that provide access to Wikidata dumps: [1]http://lod.openlinksw.com/sparql -- 61 Billion+ RDF triples culled from across the LOD Cloud (if you lookup Wikidata URIs that are objects of owl:sameAs relations you'll end up in Wikidata own Linked Data Space) [2]http://wikidata.metaphacts.com/sparql -- another endpoint I discovered yesterday . ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Il 08/04/2015 16:36, Markus Krötzsch ha scritto: On 08.04.2015 15:07, Nicola Vitucci wrote: Hi Markus, would you recommend to add some sort of patch until the new dumps are out, either in the data (by adding some triples to a temporary graph) or just in the Web interface for the external links? If you need it ASAP, you could actually just implement it in our Java code and make a pull request. It should not be too much effort. You can use the issue to ask about details if you are not sure what to do. Otherwise the ETA would be end of April/beginning of May (several other RDF extensions are currently being worked on and will happen first, e.g., ranks in RDF). I don't need it right now, so given the short ETA I'd wait. Anyway, in order to let people use external links more easily, I could just manually drop the last letter (or apply any other rule) only in the href links for now, while leaving the URIs intact. Do you see any harm in this? Nicola ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
On 08.04.2015 15:07, Nicola Vitucci wrote: Hi Markus, would you recommend to add some sort of patch until the new dumps are out, either in the data (by adding some triples to a temporary graph) or just in the Web interface for the external links? If you need it ASAP, you could actually just implement it in our Java code and make a pull request. It should not be too much effort. You can use the issue to ask about details if you are not sure what to do. Otherwise the ETA would be end of April/beginning of May (several other RDF extensions are currently being worked on and will happen first, e.g., ranks in RDF). Cheers Markus Cheers, Nicola (wikisparql.org) Il 08/04/2015 14:49, Markus Krötzsch ha scritto: Hi Jean-Baptiste, Your observation is correct. This is because a single Wikidata statement (with one Wikidata property) does not translate into a single triple (with one RDF property) in RDF. Rather, several RDF triples are used, they need to use more than one property, and these properties have different declarations (e.g., some are DatatypeProperties and some are ObjectProperties). Therefore, we create property variants, currently by appending letters like s. The current RDF encoding is documented in our ISWC 2014 paper: https://ddll.inf.tu-dresden.de/web/Inproceedings4005/en You are still right that there is a problem here in that you cannot get from P123s to P123 in the current RDF. This is being worked on: https://github.com/Wikidata/Wikidata-Toolkit/issues/84 The dumps will hopefully have this soon. Regards, Markus On 08.04.2015 12:05, Jean-Baptiste Pressac wrote: Hello, Thank you for this initiative. However, there is a little problem with the Properties on the result pages. For instance on the result page of this query http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/Q18335803%3E all Wikidata properties have an extra letter after the property ID, for instance P463 https://www.wikidata.org/wiki/Property:P463 has an extra s (P463s) so that the link to this property (on the arrow icon) leads to a bad request page. A click on this link : http://www.wikidata.org/entity/P463s Brings you on this page rather than http://www.wikidata.org/entity/P463. There is also a problem with the link to the wikidata ontology on this page http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/VTe085defe2fad71c9445145ec538e724c%3E. For instance time precision has a link to http://www.wikidata.org/ontology#timePrecision which does not exists. Cheers, Jean-Baptiste Pressac Traitement et analyse de bases de données Production et diffusion de corpus numériques Centre de Recherche Bretonne et Celtique Unité mixte de service (UMS) 3554 20 rue Duquesne CS 93837 29238 Brest cedex 3 tel : +33 (0)2 98 01 68 95 fax : +33 (0)2 98 01 63 93 Le 23/03/2015 12:51, Marco Fossati a écrit : Hi everyone, I'd just like to announce another experimental Wikidata SPARQL endpoint [1], kindly provided by the folks at SpazioDati [2]. It contains both the simplified and the complete dumps, as per [3]. Each dump file is stored under a different named graph. We are collecting the query logs, and will share the most frequent queries. Cheers! [1] http://wikisparql.org/ [2] http://spaziodati.eu/en/ [3] http://tools.wmflabs.org/wikidata-exports/rdf/exports/20150223/ On 3/21/15 1:00 PM, wikidata-l-requ...@lists.wikimedia.org wrote: On 3/20/15 2:08 PM, Markus Kroetzsch wrote: Dear all, Thanks to the people at the Center of Semantic Web Research in Chile [1], we have a very first public SPARQL endpoint for Wikidata running. This is very preliminary, so do not rely on it in applications and expect things to fail, but you may still enjoy some things. http://milenio.dcc.uchile.cl/sparql You have a SPARQL that provides access to Wikidata dumps loaded into an RDF compliant RDBMS (in this case a Virtuoso RDBMS instance). I emphasis a because the first isn't accurate. There are other endpoints that provide access to Wikidata dumps: [1]http://lod.openlinksw.com/sparql -- 61 Billion+ RDF triples culled from across the LOD Cloud (if you lookup Wikidata URIs that are objects of owl:sameAs relations you'll end up in Wikidata own Linked Data Space) [2]http://wikidata.metaphacts.com/sparql -- another endpoint I discovered yesterday . ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
On 08.04.2015 16:02, Jean-Baptiste Pressac wrote: Thank you, I will have a look to your publication to have a better understanding of the mecanism of RDFisation. Are you also going to solve the problem with the links to the wikidata ontology ? For instance on this page http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/VTe085defe2fad71c9445145ec538e724c%3E time precision has a link to http://www.wikidata.org/ontology#timePrecision which does not exists. Yes, all URIs should eventually be resolvable. We could not make this work with our RDF dumps but the ongoing official RDF dump discussions will certainly result in resolvable URIs. There will also be some changes in the URI schemes as part of this process. Stay tuned. ;-) Markus Regards, Jean-Baptiste Pressac ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Thanks, Jean-Baptiste Pressac Traitement et analyse de bases de données Production et diffusion de corpus numériques Centre de Recherche Bretonne et Celtique Unité mixte de service (UMS) 3554 20 rue Duquesne CS 93837 29238 Brest cedex 3 tel : +33 (0)2 98 01 68 95 fax : +33 (0)2 98 01 63 93 Le 08/04/2015 16:33, Markus Krötzsch a écrit : On 08.04.2015 16:02, Jean-Baptiste Pressac wrote: Thank you, I will have a look to your publication to have a better understanding of the mecanism of RDFisation. Are you also going to solve the problem with the links to the wikidata ontology ? For instance on this page http://wikisparql.org/sparql?query=DESCRIBE+%3Chttp%3A//www.wikidata.org/entity/VTe085defe2fad71c9445145ec538e724c%3E time precision has a link to http://www.wikidata.org/ontology#timePrecision which does not exists. Yes, all URIs should eventually be resolvable. We could not make this work with our RDF dumps but the ongoing official RDF dump discussions will certainly result in resolvable URIs. There will also be some changes in the URI schemes as part of this process. Stay tuned. ;-) Markus Regards, Jean-Baptiste Pressac ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l attachment: Jean-Baptiste_Pressac.vcf___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Hi everyone, I'd just like to announce another experimental Wikidata SPARQL endpoint [1], kindly provided by the folks at SpazioDati [2]. It contains both the simplified and the complete dumps, as per [3]. Each dump file is stored under a different named graph. We are collecting the query logs, and will share the most frequent queries. Cheers! [1] http://wikisparql.org/ [2] http://spaziodati.eu/en/ [3] http://tools.wmflabs.org/wikidata-exports/rdf/exports/20150223/ On 3/21/15 1:00 PM, wikidata-l-requ...@lists.wikimedia.org wrote: On 3/20/15 2:08 PM, Markus Kroetzsch wrote: Dear all, Thanks to the people at the Center of Semantic Web Research in Chile [1], we have a very first public SPARQL endpoint for Wikidata running. This is very preliminary, so do not rely on it in applications and expect things to fail, but you may still enjoy some things. http://milenio.dcc.uchile.cl/sparql You have a SPARQL that provides access to Wikidata dumps loaded into an RDF compliant RDBMS (in this case a Virtuoso RDBMS instance). I emphasis a because the first isn't accurate. There are other endpoints that provide access to Wikidata dumps: [1]http://lod.openlinksw.com/sparql -- 61 Billion+ RDF triples culled from across the LOD Cloud (if you lookup Wikidata URIs that are objects of owl:sameAs relations you'll end up in Wikidata own Linked Data Space) [2]http://wikidata.metaphacts.com/sparql -- another endpoint I discovered yesterday . -- Marco Fossati http://about.me/marco.fossati Twitter: @hjfocs Skype: hell_j ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Brilliant, we should set up a page with a list of SPARQL endpoits for Wikidata! For production usage, it is great to have a variety to chose from. ==WARNING== The RDF format is currently in flux. The purpose of the Chilean endpoint http://milenio.dcc.uchile.cl/sparql is to gather feedback that helps us how to possibly the RDF structure for greater utility/simplicity. There will be several updates to the format in the net few weeks. Please help us to find out what is needed by also testing at http://milenio.dcc.uchile.cl/sparql. We gather query logs and are happy to share them. This said, please also tell us if other endpoints work better/differently/worse for you. Any feedback is welcome. Cheers, Markus On 23.03.2015 12:51, Marco Fossati wrote: Hi everyone, I'd just like to announce another experimental Wikidata SPARQL endpoint [1], kindly provided by the folks at SpazioDati [2]. It contains both the simplified and the complete dumps, as per [3]. Each dump file is stored under a different named graph. We are collecting the query logs, and will share the most frequent queries. Cheers! [1] http://wikisparql.org/ [2] http://spaziodati.eu/en/ [3] http://tools.wmflabs.org/wikidata-exports/rdf/exports/20150223/ On 3/21/15 1:00 PM, wikidata-l-requ...@lists.wikimedia.org wrote: On 3/20/15 2:08 PM, Markus Kroetzsch wrote: Dear all, Thanks to the people at the Center of Semantic Web Research in Chile [1], we have a very first public SPARQL endpoint for Wikidata running. This is very preliminary, so do not rely on it in applications and expect things to fail, but you may still enjoy some things. http://milenio.dcc.uchile.cl/sparql You have a SPARQL that provides access to Wikidata dumps loaded into an RDF compliant RDBMS (in this case a Virtuoso RDBMS instance). I emphasis a because the first isn't accurate. There are other endpoints that provide access to Wikidata dumps: [1]http://lod.openlinksw.com/sparql -- 61 Billion+ RDF triples culled from across the LOD Cloud (if you lookup Wikidata URIs that are objects of owl:sameAs relations you'll end up in Wikidata own Linked Data Space) [2]http://wikidata.metaphacts.com/sparql -- another endpoint I discovered yesterday . ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
On 3/20/15 4:09 PM, Markus Kroetzsch wrote:
Hi Dmitriy,
Yes, you are right. There are some countries that have a value for
dissolved or abolished (P576) but no end date for instance of
sovereign state. This includes the United Kingdom of the
Netherlands. Probably these should get an end date for their P31, or
we should use P576 in the query.
A list of all states that have no end date to their P31 sovereign
state but that do have a P576 date:
PREFIX : http://www.wikidata.org/entity/
SELECT ?country ?countryName
WHERE {
?country :P576c ?disolutionDate .
?country :P31s ?statement .
?statement :P31v :Q3624078 .
FILTER NOT EXISTS { ?statement :P582q ?endDate }
?country rdfs:label ?countryName FILTER(lang(?countryName)=en)
}
See:
[1]
http://milenio.dcc.uchile.cl/sparql?default-graph-uri=query=%0D%0APREFIX+%3A+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2F%3E%0D%0ASELECT+%3Fcountry+%3FcountryName%0D%0AWHERE+%7B%0D%0A++%3Fcountry+%3AP576c+%3FdisolutionDate+.%0D%0A++%3Fcountry+%3AP31s+%3Fstatement+.%0D%0A++%3Fstatement+%3AP31v+%3AQ3624078+.%0D%0A+FILTER+NOT+EXISTS+%7B+%3Fstatement+%3AP582q+%3FendDate+%7D%0D%0A++%3Fcountry+rdfs%3Alabel+%3FcountryName+FILTER%28lang%28%3FcountryName%29%3D%22en%22%29%0D%0A%7D+format=text%2Fhtmltimeout=0debug=on
A list of all states that have an end date to their P31 sovereign
state but that do not have a P576 date:
PREFIX : http://www.wikidata.org/entity/
SELECT ?country ?countryName
WHERE {
?country :P31s ?statement .
?statement :P31v :Q3624078 .
?statement :P582q ?endDate .
FILTER NOT EXISTS { ?country :P576c ?disolutionDate }
?country rdfs:label ?countryName FILTER(lang(?countryName)=en)
}
See:
http://milenio.dcc.uchile.cl/sparql?default-graph-uri=query=%0D%0APREFIX+%3A+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2F%3E%0D%0ASELECT+%3Fcountry+%3FcountryName%0D%0AWHERE+%7B%0D%0A++%3Fcountry+%3AP31s+%3Fstatement+.%0D%0A++%3Fstatement+%3AP31v+%3AQ3624078+.%0D%0A++%3Fstatement+%3AP582q+%3FendDate+.%0D%0A+FILTER+NOT+EXISTS+%7B+%3Fcountry+%3AP576c+%3FdisolutionDate+%7D%0D%0A++%3Fcountry+rdfs%3Alabel+%3FcountryName+FILTER%28lang%28%3FcountryName%29%3D%22en%22%29%0D%0A%7D+format=text%2Fhtmltimeout=0debug=on
--
Regards,
Kingsley Idehen
Founder CEO
OpenLink Software
Company Web: http://www.openlinksw.com
Personal Weblog 1: http://kidehen.blogspot.com
Personal Weblog 2: http://www.openlinksw.com/blog/~kidehen
Twitter Profile: https://twitter.com/kidehen
Google+ Profile: https://plus.google.com/+KingsleyIdehen/about
LinkedIn Profile: http://www.linkedin.com/in/kidehen
Personal WebID: http://kingsley.idehen.net/dataspace/person/kidehen#this
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Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
Hi Markus,
Is ?statement :P31v :Q3624078 .
FILTER NOT EXISTS { ?statement :P582q ?endDate }
really enough to filter off currently non-existing countries?
Because I have such code in my Python bot:
http://paste.debian.net/162319/
And even with so many filters, there is a bit strange Kingdom of
Netherlands which duplicates Netherlands but having only few cities.
Dmitriy
On Fri, Mar 20, 2015 at 9:08 PM, Markus Kroetzsch
markus.kroetz...@tu-dresden.de wrote:
Dear all,
Thanks to the people at the Center of Semantic Web Research in Chile [1],
we have a very first public SPARQL endpoint for Wikidata running. This is
very preliminary, so do not rely on it in applications and expect things to
fail, but you may still enjoy some things.
http://milenio.dcc.uchile.cl/sparql
The endpoint has all the data from our current RDF exports in one big
database [2]. Below this email are some example queries to get you started
(this is a bit of a learning-by-doing crash course in SPARQL too, but you
may want to consult a tutorial if you don't know it ;-).
There are some known bugs in the RDF that we will hopefully fix soon [3].
Also, the service uses a dump that is already a few weeks old now. We are
more interested in testing functions right now before going production.
Also, this is a raw API interface, not a proposal for a nice UI.
Feedback (and other interesting queries) are welcome :-)
Cheers,
Markus
[1] http://ciws.cl/ -- a joint team from University of Chile and
Pontificia Universidad Catolica de Chile
[2] http://tools.wmflabs.org/wikidata-exports/rdf/
[3] https://github.com/Wikidata/Wikidata-Toolkit/issues?q=is%
3Aopen+is%3Aissue+label%3A%22RDF+export%22
==Lighthouses (Q39715) with their English label (LIMIT 100 for demo)==
PREFIX : http://www.wikidata.org/entity/
SELECT *
WHERE {
?lighthouse a :Q39715 .
?lighthouse rdfs:label ?label FILTER(LANG(?label) = en)
} LIMIT 100
(Just paste the query into the box at http://milenio.dcc.uchile.cl/sparql)
The actual query condition is in the WHERE {...} part. Things starting
with ? are variables. Basic conditions take the form of triples: subject
property value. For example, ?lighthouse a :Q39715 looks for things that
are a lighthouse (a is short for rdf:type which we use to encode P31
statements without qualifiers). The dot . is used as a separator between
triples.
Note that the label output is a bit cumbersome because you want to filter
by language (without the FILTER you get all labels in all languages). A
future UI would better fetch the labels after the query, similar to WDQ, to
get smaller faster queries.
==People born in the same place that they died in==
PREFIX : http://www.wikidata.org/entity/
SELECT ?person ?personname ?placename
WHERE {
?person a :Q5 .
?person :P19c ?place .
?person :P20c ?place .
?person rdfs:label ?personname FILTER(LANG(?personname) = en) .
?place rdfs:label ?placename FILTER(LANG(?placename) = en)
} LIMIT 100
Here we use a few actual Wikidata properties. Properties in their simple
form (Entity-Value) use ids with a c in the end, like :P19c here. Only
qualifier-free statements will be available in this form right now. Note
that we use the variable ?place in two places as a value. This is how we
query for things that have the same place in both cases.
==People who have Wikipedia (Q52) accounts==
PREFIX : http://www.wikidata.org/entity/
SELECT ?person ?personname ?username
WHERE {
?person :P553s ?statement .
?statement :P553v :Q52 .
?statement :P554q ?username .
?person rdfs:label ?personname FILTER(LANG(?personname) = en) .
} LIMIT 100
This query needs to access qualifiers of a statement for website account
on (P553). To do this in RDF (and SPARQL), we access the statement object
instead of using simple property :P553c (which would only give us the
value). The statement is found through an ...s property; its value is
found through a ...v property; its qualifiers are found through ...q
properties. Check out the graph in our paper to get the picture (
http://korrekt.org/page/Introducing_Wikidata_to_the_Linked_Data_Web).
There you can also find how references are accessed.
==Currently existing countries==
PREFIX : http://www.wikidata.org/entity/
SELECT ?country ?countryName
WHERE {
?country :P31s ?statement .
?statement :P31v :Q3624078 .
FILTER NOT EXISTS { ?statement :P582q ?endDate }
?country rdfs:label ?countryName FILTER(lang(?countryName)=en)
}
Similar pattern as with the Wikipedia accounts, but now we check that a
certain qualifier (end time) does not exist. You could also find currently
married people in this way, etc.
==Descendants of Queen Victoria (Q9439) ==
PREFIX : http://www.wikidata.org/entity/
SELECT DISTINCT *
WHERE {
:Q9439 ((^:P25c|^:P22c)+) ?person .
?person rdfs:label ?label
FILTER(LANG(?label) = en)
} LIMIT 1000
Here, ((^:P25c|^:P22c)+) is a regular expression; ^ is for
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
On 3/20/15 2:08 PM, Markus Kroetzsch wrote: Dear all, Thanks to the people at the Center of Semantic Web Research in Chile [1], we have a very first public SPARQL endpoint for Wikidata running. This is very preliminary, so do not rely on it in applications and expect things to fail, but you may still enjoy some things. http://milenio.dcc.uchile.cl/sparql You have a SPARQL that provides access to Wikidata dumps loaded into an RDF compliant RDBMS (in this case a Virtuoso RDBMS instance). I emphasis a because the first isn't accurate. There are other endpoints that provide access to Wikidata dumps: [1] http://lod.openlinksw.com/sparql -- 61 Billion+ RDF triples culled from across the LOD Cloud (if you lookup Wikidata URIs that are objects of owl:sameAs relations you'll end up in Wikidata own Linked Data Space) [2] http://wikidata.metaphacts.com/sparql -- another endpoint I discovered yesterday . #1 was actually loaded a long time ago :) Links: 1. http://lod.openlinksw.com/sparql?default-graph-uri=query=PREFIX+%3A+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2F%3E+SELECT+%3Fcountry+WHERE+%7B+%3Fcountry+%3AP31s%2F%3AP31v+%3AQ3624078+.+%7Dformat=text%2Fhtmltimeout=0debug=on -- LOD Cloud SPARQL Query Results URL 2. http://milenio.dcc.uchile.cl/sparql?default-graph-uri=query=PREFIX+%3A+%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2F%3E+SELECT+%3Fcountry+WHERE+%7B+%3Fcountry+%3AP31s%2F%3AP31v+%3AQ3624078+.+%7Dformat=text%2FhtmlCXML_redir_for_subjs=121CXML_redir_for_hrefs=timeout=0debug=on -- Center of Semantic Web Research in Chile SPARQL Query Results URL . -- Regards, Kingsley Idehen Founder CEO OpenLink Software Company Web: http://www.openlinksw.com Personal Weblog 1: http://kidehen.blogspot.com Personal Weblog 2: http://www.openlinksw.com/blog/~kidehen Twitter Profile: https://twitter.com/kidehen Google+ Profile: https://plus.google.com/+KingsleyIdehen/about LinkedIn Profile: http://www.linkedin.com/in/kidehen Personal WebID: http://kingsley.idehen.net/dataspace/person/kidehen#this smime.p7s Description: S/MIME Cryptographic Signature ___ Wikidata-l mailing list Wikidata-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l
Re: [Wikidata-l] Preliminary SPARQL endpoint for Wikidata
On 20.03.2015 19:08, Markus Kroetzsch wrote:
...
Feedback (and other interesting queries) are welcome :-)
Here's another nice query:
Find all astronomical bodies on which Wikidata has some coordinates,
ordered by the number of coordinates that refer to them:
PREFIX : http://www.wikidata.org/entity/
SELECT ?globe (COUNT(DISTINCT ?coordinatesValue) AS ?globeCount)
WHERE {
?coordinatesValue http://www.wikidata.org/ontology#globe ?globe
} ORDER BY DESC(?globeCount)
This is a bit more costly, so don't try to add labels in the query ;-)
Cheers,
Markus
--
Markus Kroetzsch
Faculty of Computer Science
Technische Universität Dresden
+49 351 463 38486
http://korrekt.org/
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