Getting started with DBpedia

Question

I want to get started using DBpedia. At the moment all I know is that DBpedia is a structured form of Wikipedia data and it can be queried using SPARQL. To me the basic idea of DBpedia (giving structure to wikipedia data) seems truly amazing, so please go easy if my question is basic.

My goal

Get simple data extracts from DBpedia. For example the countries of the world and their capitals and populations. Or get 100 random famous people, their dates and places of birth and a short description. Eventually I want to query the metadata to find what types of 'entity' are in DBpedia (eg mountains? Rivers? Cities?) and their 'properties'. But that is a separate question and I can experiment once I get the basics working.

What I found so far

In Google I found http://wiki.dbpedia.org/develop/getting-started but I think it's about installing all of DBpedia, and I only want to query it.

Also I found https://mickael.kerjean.me/2016/05/20/walkthrough-dbpedia-and-triplestore/ but it assumes you already have SPARQL or SNORQL set up, and I can't see how to do this.

Aso I found https://docs.data.world/tutorials/sparql/Your_First_Sparql_Query.html which is a guide to SPARQL but again it assumes you are using their own DataWorld environment.

On Stackoverflow I found List countries from DBpedia and List countries from DBpedia but again they assume you have set up the SPARQL environment.

Question(s)

What software do I use to write simple queries on DBpedia data - do I need SPARQL or SNORQL? Do I install them locally or can I use web-based tools? I use Windows 10 and I'm happy with SQL queries.
Once I have the software set up, what is the simplest query to get the list of countries of the world and capitals and populations?
Also how can I write a basic query to return (say) 100 random people and their basic details?

That's not a specific question, it sounds like How to query Semantic Web data in general?. — UninformedUser
"do I need SPARQL or SNORQL" -> SPARQL is the query language for RDF, it's not a software. There are a lots of APIs/tools for querying RDF data via SPARQL. Any search engine is your friend — UninformedUser
"what is the simplest query to get the list of countries of the world and capitals and populations" -> write the SPARQL query? Figure out the relations that connect countries to their capital and population. You're asking how? Well, look at some sample DBpedia countries maybe? — UninformedUser
"100 random people and their basic details" -> figure out the class for persons in DBpedia, look at the SPARQL specs for the random function + order by + limit. Figure out the properties that you think of as "basic details" . That's it — UninformedUser
Thanks for the prompt comments. I have to admit I don't know enough about DBpedia to find the relations, or how to find out a class or to find properties. Also I don't know the easiest way of querying DBpedia, is SPARQL the most widely used and best option? I was hoping for a "hello world" sort of example to get me started, eg use ABC application, type in XYZ etc. — Ubercoder

Coder Coder · Accepted Answer · 2018-02-15T14:10:45

The answer regarding your first question,actually SPARQL is a query language not a software and you can write your queries here https://dbpedia.org/sparql.

In-order to obtain countries ,their capital and respective population :

PREFIX dbo: <http://dbpedia.org/ontology/>
PREFIX dbp: <http://dbpedia.org/property/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>

SELECT  min(?country_name) as ?Country_name min(?capital_name) as ?Capital_name min(?population) as ?Population
WHERE {
?country a dbo:Country.
?country rdfs:label ?country_name.
?country dbo:capital ?capital.
?capital  rdfs:label ?capital_name.
?country ?p ?population .
FILTER(?p = dbo:populationTotal || ?p = dbp:populationCensus). 
FILTER NOT EXISTS { ?country dbo:dissolutionYear ?year }
FILTER langMatches( lang(?country_name), "en"  ).
FILTER langMatches( lang(?capital_name), "en"  ).}
GROUP BY ?country_name

For your third question, this is an example solution :

SELECT  distinct ?link ?person_full_name ?birth_year   WHERE { 
     ?link a foaf:Person. 
     ?link ?p ?person_full_name. 
     FILTER(?p IN(dbo:birthName,dbp:birthName,dbp:fullname,dbp:name)). 
     ?link rdfs:label ?person_name .    
     ?person_name bif:contains "abdul" . 
     OPTIONAL { ?link dbo:birthYear ?birth_year .  }
     FILTER(langMatches(lang(?person_full_name), "en"))
     }
     LIMIT 100

Getting started with DBpedia

2 Answers