/// <summary>
/// Applies the query to the given SPARQL endpoint
/// </summary>
public RDFDescribeQueryResult ApplyToSPARQLEndpoint(RDFSPARQLEndpoint sparqlEndpoint)
{
RDFDescribeQueryResult describeResult = new RDFDescribeQueryResult(this.ToString());
if (sparqlEndpoint != null)
{
RDFQueryEvents.RaiseDESCRIBEQueryEvaluation(String.Format("Evaluating DESCRIBE query on SPARQL endpoint '{0}'...", sparqlEndpoint));
//Establish a connection to the given SPARQL endpoint
using (WebClient webClient = new WebClient())
{
//Insert reserved "query" parameter
webClient.QueryString.Add("query", HttpUtility.UrlEncode(this.ToString()));
//Insert user-provided parameters
webClient.QueryString.Add(sparqlEndpoint.QueryParams);
//Insert request headers
webClient.Headers.Add(HttpRequestHeader.Accept, "application/turtle");
webClient.Headers.Add(HttpRequestHeader.Accept, "text/turtle");
//Send querystring to SPARQL endpoint
var sparqlResponse = webClient.DownloadData(sparqlEndpoint.BaseAddress);
//Parse response from SPARQL endpoint
if (sparqlResponse != null)
{
using (var sStream = new MemoryStream(sparqlResponse))
{
describeResult = RDFDescribeQueryResult.FromRDFGraph(RDFGraph.FromStream(RDFModelEnums.RDFFormats.Turtle, sStream));
}
describeResult.DescribeResults.TableName = this.ToString();
}
}
//Eventually adjust column names (should start with "?")
Int32 columnsCount = describeResult.DescribeResults.Columns.Count;
for (Int32 i = 0; i < columnsCount; i++)
{
if (!describeResult.DescribeResults.Columns[i].ColumnName.StartsWith("?"))
{
describeResult.DescribeResults.Columns[i].ColumnName = "?" + describeResult.DescribeResults.Columns[i].ColumnName;
}
}
RDFQueryEvents.RaiseDESCRIBEQueryEvaluation(String.Format("Evaluated DESCRIBE query on SPARQL endpoint '{0}': Found '{1}' results.", sparqlEndpoint, describeResult.DescribeResultsCount));
}
return(describeResult);
}
/// <summary>
/// Applies the query to the given SPARQL endpoint
/// </summary>
public RDFDescribeQueryResult ApplyToSPARQLEndpoint(RDFSPARQLEndpoint sparqlEndpoint)
{
string describeQueryString = this.ToString();
RDFDescribeQueryResult describeResult = new RDFDescribeQueryResult(describeQueryString);
if (sparqlEndpoint != null)
{
//Establish a connection to the given SPARQL endpoint
using (WebClient webClient = new WebClient())
{
//Insert reserved "query" parameter
webClient.QueryString.Add("query", HttpUtility.UrlEncode(describeQueryString));
//Insert user-provided parameters
webClient.QueryString.Add(sparqlEndpoint.QueryParams);
//Insert request headers
webClient.Headers.Add(HttpRequestHeader.Accept, "application/turtle");
webClient.Headers.Add(HttpRequestHeader.Accept, "text/turtle");
//Send querystring to SPARQL endpoint
byte[] sparqlResponse = webClient.DownloadData(sparqlEndpoint.BaseAddress);
//Parse response from SPARQL endpoint
if (sparqlResponse != null)
{
using (MemoryStream sStream = new MemoryStream(sparqlResponse))
describeResult = RDFDescribeQueryResult.FromRDFGraph(RDFGraph.FromStream(RDFModelEnums.RDFFormats.Turtle, sStream));
describeResult.DescribeResults.TableName = describeQueryString;
}
}
//Eventually adjust column names (should start with "?")
int columnsCount = describeResult.DescribeResults.Columns.Count;
for (int i = 0; i < columnsCount; i++)
{
if (!describeResult.DescribeResults.Columns[i].ColumnName.StartsWith("?"))
{
describeResult.DescribeResults.Columns[i].ColumnName = string.Concat("?", describeResult.DescribeResults.Columns[i].ColumnName);
}
}
}
return(describeResult);
}
