所以我有一个查询,并试图在调试输出中显示它,当我运行文件时,它给了我一个以 iisexpress.exe 开头的输出列表:https ://gyazo.com/fd9eb832dfcc08571b31490103b85b49 但没有实际结果?我第一次尝试使用 dotnetRDF 在 Visual Studios2015 上运行查询。我的代码如下:
public static void Main(String[] args)
{
Debug.WriteLine("SQLAQL query example");
//Define a remote endpoint
//Use the DBPedia SPARQL endpoint with the default Graph set to DBPedia
SparqlRemoteEndpoint endpoint = new SparqlRemoteEndpoint(new Uri("http://dbpedia.org/sparql"), "http://dbpedia.org");
//SPARQL query to show countries, population, capital for countries where population is more than 100000 and limit results to 50
String queryString = "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> " +
"PREFIX type: <http://dbpedia.org/class/yago/> " +
"PREFIX prop: <http://dbpedia.org/property/> " +
"SELECT ?country_name ?population ?cptl " +
"WHERE { " +
"?country rdf:type type:Country108544813. " +
"?country rdfs:label ?country_name. " +
"?country prop:populationEstimate ?population. " +
"?country dbo:capital ?cptl " +
"FILTER (?population > 1000000000) . " +
"}" +
"LIMIT 50 ";
Debug.WriteLine("queryString: [" + queryString + "]");
//Make a SELECT query against the Endpoint
SparqlResultSet results = endpoint.QueryWithResultSet(queryString);
foreach (SparqlResult result in results)
{
Debug.WriteLine(result.ToString());
}
}
刚刚学习 SPARQL,所以这可能是一个非常基本的问题。非常感谢:)