Sparql endpoint

The following contains some sparql query examples

Query 1, find events which have country location, city location, start date, end date, and home page

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX swivt: <http://semantic-mediawiki.org/swivt/1.0#>
PREFIX property: <http://openresearch.org/Special:URIResolver/Property-3A>
PREFIX category: <http://openresearch.org/Special:URIResolver/Category-3A>
PREFIX wiki: <http://openresearch.org/Special:URIResolver/>
PREFIX icaltzd: <https://www.w3.org/2002/12/cal/icaltzd#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>

SELECT ?event ?endDate ?startDate ?city ?country ?wikipage ?homepage WHERE {
  ?e property:Has_location_country category:Germany.
  ?e rdfs:label ?event.
  ?e property:Has_location_city ?city.
  ?e property:Has_location_country ?country.
  ?e icaltzd:dtend ?endDate.
  ?e icaltzd:dtstart ?startDate.
  ?e foaf:homepage ?homepage.
  ?e swivt:page ?wikipage.
} ORDER BY DESC(?startDate) LIMIT 100

Query 2, get events happen in Europe between 2016-01-01 and 2017-01-01, with acceptance rate less than 25%, with related to "semantic web"

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX swivt: <http://semantic-mediawiki.org/swivt/1.0#>
PREFIX property: <http://openresearch.org/Special:URIResolver/Property-3A>
PREFIX category: <http://openresearch.org/Special:URIResolver/Category-3A>
PREFIX wiki: <http://openresearch.org/Special:URIResolver/>
PREFIX site: <http://openresearch.org/Special:ExportRDF/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX icaltzd: <https://www.w3.org/2002/12/cal/icaltzd#>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>

SELECT ?event ?endDate ?startDate ?city ?country ?wikipage ?acceptanceRate ?continent WHERE {
  ?e rdfs:label ?event.
  ?e property:Has_location_country ?country.
  ?country rdfs:subClassOf ?partContinent.
  ?partContinent rdfs:subClassOf ?continent.
  ?continent rdfs:isDefinedBy site:Category:Europe.
  ?e a category:Semantic_Web.
  ?e icaltzd:dtstart ?startDate.
  ?e icaltzd:dtend ?endDate.
  ?e property:Acceptance_rate ?acceptanceRate.
  ?e property:Has_location_city ?city.
  ?e swivt:page ?wikipage.
  FILTER (?acceptanceRate < 25.0 && ?startDate >= "2016-01-01"^^xsd:date && ?endDate < "2017-01-01"^^xsd:date).
} ORDER BY DESC(?startDate) LIMIT 100

Query 3, get pc members and general chairs who involve semantic web related events in last 7 years

PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX swivt: <http://semantic-mediawiki.org/swivt/1.0#>
PREFIX urir: <http://openresearch.org/Special:URIResolver/>
PREFIX property: <http://openresearch.org/Special:URIResolver/Property-3A>
PREFIX category: <http://openresearch.org/Special:URIResolver/Category-3A>
PREFIX wiki: <http://openresearch.org/Special:URIResolver/>
PREFIX site: <http://openresearch.org/Special:ExportRDF/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX icaltzd: <https://www.w3.org/2002/12/cal/icaltzd#>


SELECT ?event ?endDate ?startDate ?pcMember ?geMember WHERE {
  ?e rdfs:label ?event.
  ?e property:Has_PC_member ?pcMember.
  ?e property:Has_general_chair ?geMember.
  ?e a category:Semantic_Web.
  ?e icaltzd:dtstart ?startDate.
  ?e icaltzd:dtend ?endDate.
  minus {?e property:Has_PC_member urir:Some_person.}
  FILTER (?startDate >= "2010-01-01"^^xsd:date && ?endDate < "2017-01-01"^^xsd:date).
} ORDER BY DESC(?startDate) LIMIT 10

Query 4, Which period of year have had the most number of events organized for a specific field or topic

        PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
        PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
        PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
        PREFIX property: <http://openresearch.org/Special:URIResolver/Property-3A>
        PREFIX category: <http://openresearch.org/Special:URIResolver/Category-3A>
        PREFIX icaltzd: <https://www.w3.org/2002/12/cal/icaltzd#>


        SELECT ?month (count(?e) as ?numEvents) WHERE
        {
          ?e rdfs:label ?event.
          ?e icaltzd:dtend ?endDate.
          ?e icaltzd:dtstart ?startDate.
          ?e a category:Semantic_Web.
          Filter (datatype(?endDate) != xsd:double && datatype(?startDate) != xsd:double)
          FILTER (?startDate >= "2016-01-01"^^xsd:date && ?endDate < "2017-01-01"^^xsd:date).
          VALUES ?month {1 2 3 4 5 6 7 8 9 10 11 12}
          FILTER ( month(?startDate) <= ?month && ?month <= month(?endDate) )
        } GROUP BY ?month