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Tools : SPARQL
- Wikidata is a free and open knowledge base that can be read and edited by both humans and machines.
- Wikidata acts as central storage for the structured data of its Wikimedia sister projects including Wikipedia, Wikivoyage, Wiktionary, Wikisource, and others.
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Creating a dictionary using Wikidata Query Service/SPARQL saves time and energy. Wikidata is a knowledge database and SPARQL is a language to formulate queries using knowledge databases.
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To start with, open the home page of WDQS/SPARQL : https://www.wikidata.org/wiki/Wikidata:WikiFactMine/Core_SPARQL
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From the list on the left hand side of the home page, go to Query Service, this takes you to: https : //query.wikidata.org/
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This opens the SPARQL query page where you can add your query. If you find any trouble in creating a SPARQL Query, you can create it from: https://www.wikidata.org/wiki/Wikidata:SPARQL_query_service/Query_Helper#How_to_create_a_Query?
OR You can create a query without knowing SPARQL, it's too easy. Go to Query Helper on the left side of Query Editor and apply filters to your search, then test it by running the query and so on.
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Wikidata Query Service provides various tools to build a SPARQL Query. One of them is Wikidata Query Builder :
https://tools.wmflabs.org/wd-query-builder/
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Just do the related search and Click on 'Show Query', this has built a SPARQL Query for you. eg. in my case, the property is Crossref Funder ID (P3153).
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Set the limit of your results, it is by default 20, you can change it by clicking on to 'Query Options', I changed it to 20000 and got 13442 results.
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Go to 'Search results': You will get a list of the items which you are searching for.
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Go to 'link' and then 'SPARQL endpoint' and it's done.
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The dictionary created is : https://github.com/petermr/openVirus/blob/master/dictionaries/funders/sparql%20(4)
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Reference TUTORIAL for creating queries : https://www.youtube.com/watch?v=kJph4q0Im98
We often need the human-readable labels for an Item. Almost all items have labels. However you have to use a label SERVICE
for this:
SELECT ?funder ?funderLabel WHERE {
?funder wdt:P3153 ?crossrefid .
SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
}
Every item has a label
defined by adding Label
as a suffix. So funder
has funderLabel
. The label is not a property but has to be generated. This is through a SERVICE
SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
This is not easy to remember. It will generate labels for all the variables (i.e. ?foo
) in the SELECT.
Here's the first part of my output:
funder. funderLabel
wd:Q750619 Chugai Pharmaceutical Co.
wd:Q746879 British Medical Research Council
wd:Q782600 Linköping University