Database query on Wikipedia

Support Query DBpedia SPARQL
1

Good day dbpedia community,

We urgently need help with a database search because we are currently running a school project that has to do with the following data.

Our problem is:

We need from Wikipedia all data entries of the information boxes of all cities and villages throughout Germany

These records are needed:

  • State
  • Government district
  • District
  • Inhabitants
  • Community key
  • Post Code
  • Address
  • Website
  • Coat of Arms (as a .svg file)

I hope you can get this data as we need it for our school project.

Yours sincerely

Thomas Heidrich

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2

Hello, DBpedia itself provides extracted and structured data for more then 140 Wikipedia languages stored as RDF. You can query this data on the public endpoint http://dbpedia.org/sparql, setting up your own RDF store or by processing the raw data dumps which can be found e.g https://databus.dbpedia.org/dbpedia/mappings. If you are new to linked data and rdf i can help you to get started with your tasks to accquire the right data for your purpose. Please pm me at Slack: https://dbpedia-slack.herokuapp.com/ User: marvinh

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3

Hello marvinh, first of all thanks for the quick answer but I am still very new in this area. Although I know how to retrieve SQL databases and uses but have never done anything with SparSQL special with RDF.

4

Okay, SPARQL is quite easy if you know SQL, best way is to lean it on example queries.
Most difficult part is to know which vocabular/ontology is used to query the data reasonably.
DBpedia has its own ontology https://wiki.dbpedia.org/services-resources/ontology

Example query:

PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX rdfs:   <http://www.w3.org/2000/01/rdf-schema#>
SELECT *
{
   ?City a dbo:City ;
   rdfs:label ?Label ;
   dbo:postalCode ?PostalCode .
   Filter ( lang(?Label) = "en" )
} Limit 100

https://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query=PREFIX+dbo%3A+<http%3A%2F%2Fdbpedia.org%2Fontology%2F> PREFIX+rdfs%3A+++<http%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23> SELECT+* { +%3FCity+a+dbo%3ACity+%3B +++++++rdfs%3Alabel+%3FLabel+%3B +++++++dbo%3ApostalCode+%3FPostalCode+. +Filter+(+lang(%3FLabel)+%3D+"en"+) }+Limit+100&format=text%2Fhtml&CXML_redir_for_subjs=121&CXML_redir_for_hrefs=&timeout=30000&debug=on&run=+Run+Query+

“dbo” is used as a substitution for the in the PREFIX section defined URI http://dbpedia.org/ontology/

5

Thanks for your quick response the only problem I still have is how I limit this to Germany
:innocent::grinning:

6

@hopver I’ve now tried to make it like this on the tutorial website and came out:

http://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query=PREFIX+dbo%3A+<http%3A%2F%2Fdbpedia.org%2Fontology%2F> PREFIX+rdfs%3A+<http%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23> SELECT+* { +++%3FCity+a+dbo%3Acity+%3B +++rdfs%3Alabel+%3FLabel%3B +++rdf%3AProperty+%3Fpopulation+%3B +++rdfs%3AsubClassOf+%3Fdistrict+%3B +++rdfs%3Alabel+%3Faddress+%3B +++rdfs%3Alabel+%3Fwebsite+%3B +++dbo%3ApostalCode+%3FPostalCode+. +++Filter+(+lang(%3FLabel)+%3D+"en"+) }+LIMIT+100&format=text%2Fhtml&CXML_redir_for_subjs=121&CXML_redir_for_hrefs=&timeout=30000&debug=on&run=+Run+Query+

7

Better example for https://dbpedia.org/sparql

PREFIX dbr: http://dbpedia.org/resource/
PREFIX dbo: http://dbpedia.org/ontology/
PREFIX rdfs: http://www.w3.org/2000/01/rdf-schema#

SELECT * {

?City a dbo:City ;
rdfs:label ?Label .

Filter( lang(?Label) = ‘de’ )

Optional { ?City dbo:country dbr:Germany . }
Optional { ?City dbo:populationTotal ?Population . }
Optional { ?City dbo:postalCode ?postalCode . }
Optional { ?City dbo:thumbnail ?coatOfArms . }

} Limit 100

Still the Problem that it looks like that EN-DBpedia is missing some Information for your purpose. Maybe they are contained in the DE version. You can have a look at e.g http://global.dbpedia.org/?s=http%3A%2F%2Fdbpedia.org%2Fresource%2FOberschneiding and search for missing properties, in the source column it will show where the data comes from.

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