/// <summary>
/// Builds a query result corresponding to the given graph
/// </summary>
public static RDFDescribeQueryResult FromRDFGraph(RDFGraph graph) {
RDFDescribeQueryResult result = new RDFDescribeQueryResult(String.Empty);
if (graph != null) {
//Transform the graph into a datatable and assign it to the query result
result.DescribeResults = graph.ToDataTable();
}
return result;
}
/// <summary>
/// Gets a query result corresponding to the given memory store
/// </summary>
public static RDFDescribeQueryResult FromRDFMemoryStore(RDFMemoryStore store)
{
RDFDescribeQueryResult result = new RDFDescribeQueryResult(string.Empty);
if (store != null)
{
//Transform the memory store into a datatable and assign it to the query result
result.DescribeResults = store.ToDataTable();
}
return(result);
}
/// <summary>
/// Gets a query result corresponding to the given graph
/// </summary>
public static RDFDescribeQueryResult FromRDFGraph(RDFGraph graph)
{
RDFDescribeQueryResult result = new RDFDescribeQueryResult(string.Empty);
if (graph != null)
{
//Transform the graph into a datatable and assign it to the query result
result.DescribeResults = graph.ToDataTable();
}
return(result);
}
/// <summary>
/// Applies the query to the given store
/// </summary>
public RDFDescribeQueryResult ApplyToStore(RDFStore store)
{
if (store != null)
{
this.PatternGroupResultTables.Clear();
this.PatternResultTables.Clear();
RDFDescribeQueryResult describeResult = new RDFDescribeQueryResult(this.ToString());
if (!this.IsEmpty)
{
//Iterate the pattern groups of the query
foreach (RDFPatternGroup patternGroup in this.PatternGroups)
{
//Step 1: Get the intermediate result tables of the current pattern group
RDFDescribeQueryEngine.EvaluatePatterns(this, patternGroup, store);
//Step 2: Get the result table of the current pattern group
RDFDescribeQueryEngine.CombinePatterns(this, patternGroup);
//Step 3: Apply the filters of the current pattern group to its result table
RDFDescribeQueryEngine.ApplyFilters(this, patternGroup);
}
//Step 4: Get the result table of the query
DataTable queryResultTable = RDFQueryEngine.CombineTables(this.PatternGroupResultTables.Values.ToList <DataTable>(), false);
//Step 5: Describe the terms from the result table
DataTable describeResultTable = RDFDescribeQueryEngine.DescribeTerms(this, store, queryResultTable);
//Step 6: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFDescribeQueryEngine.ApplyModifiers(this, describeResultTable);
}
else
{
//In this case the only chance to proceed is to have resources in the describe terms,
//which will be used to search for S-P-O data. Variables are omitted in this scenario.
if (this.DescribeTerms.Any(dt => dt is RDFResource))
{
//Step 1: Describe the terms from the result table
DataTable describeResultTable = RDFDescribeQueryEngine.DescribeTerms(this, store, new DataTable());
//Step 2: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFDescribeQueryEngine.ApplyModifiers(this, describeResultTable);
}
}
return(describeResult);
}
throw new RDFQueryException("Cannot execute DESCRIBE query because given \"store\" parameter is null.");
}
/// <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);
}
/// <summary>
/// Applies the query to the given federation
/// </summary>
public RDFDescribeQueryResult ApplyToFederation(RDFFederation federation) {
if (federation != null) {
this.PatternGroupResultTables.Clear();
this.PatternResultTables.Clear();
RDFDescribeQueryResult describeResult = new RDFDescribeQueryResult(this.ToString());
if (!this.IsEmpty) {
//Iterate the pattern groups of the query
var fedPatternResultTables = new Dictionary<RDFPatternGroup, List<DataTable>>();
foreach (RDFPatternGroup patternGroup in this.PatternGroups) {
#region TrueFederations
foreach (RDFStore store in federation.Stores.Values) {
//Step 1: Evaluate the patterns of the current pattern group on the current store
RDFDescribeQueryEngine.EvaluatePatterns(this, patternGroup, store);
//Step 2: Federate the patterns of the current pattern group on the current store
if (!fedPatternResultTables.ContainsKey(patternGroup)) {
fedPatternResultTables.Add(patternGroup, this.PatternResultTables[patternGroup]);
}
else {
fedPatternResultTables[patternGroup].ForEach(fprt =>
fprt.Merge(this.PatternResultTables[patternGroup].Single(prt => prt.TableName.Equals(fprt.TableName, StringComparison.Ordinal)), true, MissingSchemaAction.Add));
}
}
this.PatternResultTables[patternGroup] = fedPatternResultTables[patternGroup];
#endregion
//Step 3: Get the result table of the current pattern group
RDFDescribeQueryEngine.CombinePatterns(this, patternGroup);
//Step 4: Apply the filters of the current pattern group to its result table
RDFDescribeQueryEngine.ApplyFilters(this, patternGroup);
}
//Step 5: Get the result table of the query
DataTable queryResultTable = RDFQueryEngine.CombineTables(this.PatternGroupResultTables.Values.ToList<DataTable>(), false);
//Step 6: Describe the terms on each store and merge them in the federated result table
DataTable describeResultTable = new DataTable(this.ToString());
foreach (RDFStore store in federation.Stores.Values) {
describeResultTable.Merge(RDFDescribeQueryEngine.DescribeTerms(this, store, queryResultTable), true, MissingSchemaAction.Add);
}
//Step 7: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFDescribeQueryEngine.ApplyModifiers(this, describeResultTable);
}
else {
//In this case the only chance to proceed is to have resources in the describe terms,
//which will be used to search for S-P-O data. Variables are ignored in this scenario.
if (this.DescribeTerms.Any(dt => dt is RDFResource)) {
//Step 1: Describe the terms on each store and merge them in the federated result table
DataTable describeResultTable = new DataTable(this.ToString());
foreach (RDFStore store in federation.Stores.Values) {
describeResultTable.Merge(RDFDescribeQueryEngine.DescribeTerms(this, store, new DataTable()), true, MissingSchemaAction.Add);
}
//Step 2: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFDescribeQueryEngine.ApplyModifiers(this, describeResultTable);
}
}
return describeResult;
}
throw new RDFQueryException("Cannot execute DESCRIBE query because given \"federation\" parameter is null.");
}
/// <summary>
/// Applies the query to the given store
/// </summary>
public RDFDescribeQueryResult ApplyToStore(RDFStore store) {
if (store != null) {
this.PatternGroupResultTables.Clear();
this.PatternResultTables.Clear();
RDFDescribeQueryResult describeResult = new RDFDescribeQueryResult(this.ToString());
if (!this.IsEmpty) {
//Iterate the pattern groups of the query
foreach (RDFPatternGroup patternGroup in this.PatternGroups) {
//Step 1: Get the intermediate result tables of the current pattern group
RDFDescribeQueryEngine.EvaluatePatterns(this, patternGroup, store);
//Step 2: Get the result table of the current pattern group
RDFDescribeQueryEngine.CombinePatterns(this, patternGroup);
//Step 3: Apply the filters of the current pattern group to its result table
RDFDescribeQueryEngine.ApplyFilters(this, patternGroup);
}
//Step 4: Get the result table of the query
DataTable queryResultTable = RDFQueryEngine.CombineTables(this.PatternGroupResultTables.Values.ToList<DataTable>(), false);
//Step 5: Describe the terms from the result table
DataTable describeResultTable = RDFDescribeQueryEngine.DescribeTerms(this, store, queryResultTable);
//Step 6: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFDescribeQueryEngine.ApplyModifiers(this, describeResultTable);
}
else {
//In this case the only chance to proceed is to have resources in the describe terms,
//which will be used to search for S-P-O data. Variables are omitted in this scenario.
if (this.DescribeTerms.Any(dt => dt is RDFResource)) {
//Step 1: Describe the terms from the result table
DataTable describeResultTable = RDFDescribeQueryEngine.DescribeTerms(this, store, new DataTable());
//Step 2: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFDescribeQueryEngine.ApplyModifiers(this, describeResultTable);
}
}
return describeResult;
}
throw new RDFQueryException("Cannot execute DESCRIBE query because given \"store\" parameter is null.");
}
/// <summary>
/// Applies the query to the given federation
/// </summary>
public RDFDescribeQueryResult ApplyToFederation(RDFFederation federation)
{
if (federation != null)
{
this.PatternGroupResultTables.Clear();
this.PatternResultTables.Clear();
RDFDescribeQueryResult describeResult = new RDFDescribeQueryResult(this.ToString());
if (!this.IsEmpty)
{
//Iterate the pattern groups of the query
var fedPatternResultTables = new Dictionary <RDFPatternGroup, List <DataTable> >();
foreach (RDFPatternGroup patternGroup in this.PatternGroups)
{
#region TrueFederations
foreach (RDFStore store in federation.Stores.Values)
{
//Step 1: Evaluate the patterns of the current pattern group on the current store
RDFDescribeQueryEngine.EvaluatePatterns(this, patternGroup, store);
//Step 2: Federate the patterns of the current pattern group on the current store
if (!fedPatternResultTables.ContainsKey(patternGroup))
{
fedPatternResultTables.Add(patternGroup, this.PatternResultTables[patternGroup]);
}
else
{
fedPatternResultTables[patternGroup].ForEach(fprt =>
fprt.Merge(this.PatternResultTables[patternGroup].Single(prt => prt.TableName.Equals(fprt.TableName, StringComparison.Ordinal)), true, MissingSchemaAction.Add));
}
}
this.PatternResultTables[patternGroup] = fedPatternResultTables[patternGroup];
#endregion
//Step 3: Get the result table of the current pattern group
RDFDescribeQueryEngine.CombinePatterns(this, patternGroup);
//Step 4: Apply the filters of the current pattern group to its result table
RDFDescribeQueryEngine.ApplyFilters(this, patternGroup);
}
//Step 5: Get the result table of the query
DataTable queryResultTable = RDFQueryEngine.CombineTables(this.PatternGroupResultTables.Values.ToList <DataTable>(), false);
//Step 6: Describe the terms on each store and merge them in the federated result table
DataTable describeResultTable = new DataTable(this.ToString());
foreach (RDFStore store in federation.Stores.Values)
{
describeResultTable.Merge(RDFDescribeQueryEngine.DescribeTerms(this, store, queryResultTable), true, MissingSchemaAction.Add);
}
//Step 7: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFDescribeQueryEngine.ApplyModifiers(this, describeResultTable);
}
else
{
//In this case the only chance to proceed is to have resources in the describe terms,
//which will be used to search for S-P-O data. Variables are ignored in this scenario.
if (this.DescribeTerms.Any(dt => dt is RDFResource))
{
//Step 1: Describe the terms on each store and merge them in the federated result table
DataTable describeResultTable = new DataTable(this.ToString());
foreach (RDFStore store in federation.Stores.Values)
{
describeResultTable.Merge(RDFDescribeQueryEngine.DescribeTerms(this, store, new DataTable()), true, MissingSchemaAction.Add);
}
//Step 2: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFDescribeQueryEngine.ApplyModifiers(this, describeResultTable);
}
}
return(describeResult);
}
throw new RDFQueryException("Cannot execute DESCRIBE query because given \"federation\" parameter is null.");
}
/// <summary>
/// Applies the query to the given datasource
/// </summary>
internal RDFDescribeQueryResult ApplyToDataSource(RDFDataSource datasource)
{
this.PatternGroupResultTables.Clear();
this.PatternResultTables.Clear();
RDFDescribeQueryResult describeResult = new RDFDescribeQueryResult(this.ToString());
if (this.PatternGroups.Any())
{
//Iterate the pattern groups of the query
var fedPatternResultTables = new Dictionary <RDFPatternGroup, List <DataTable> >();
foreach (var patternGroup in this.PatternGroups)
{
//Step 1: Get the intermediate result tables of the current pattern group
if (datasource.IsFederation())
{
#region TrueFederations
foreach (var store in (RDFFederation)datasource)
{
//Step FED.1: Evaluate the patterns of the current pattern group on the current store
RDFQueryEngine.EvaluatePatterns(this, patternGroup, store);
//Step FED.2: Federate the patterns of the current pattern group on the current store
if (!fedPatternResultTables.ContainsKey(patternGroup))
{
fedPatternResultTables.Add(patternGroup, this.PatternResultTables[patternGroup]);
}
else
{
fedPatternResultTables[patternGroup].ForEach(fprt =>
fprt.Merge(this.PatternResultTables[patternGroup].Single(prt => prt.TableName.Equals(fprt.TableName, StringComparison.Ordinal)), true, MissingSchemaAction.Add));
}
}
this.PatternResultTables[patternGroup] = fedPatternResultTables[patternGroup];
#endregion
}
else
{
RDFQueryEngine.EvaluatePatterns(this, patternGroup, datasource);
}
//Step 2: Get the result table of the current pattern group
RDFQueryEngine.CombinePatterns(this, patternGroup);
//Step 3: Apply the filters of the current pattern group to its result table
RDFQueryEngine.ApplyFilters(this, patternGroup);
}
//Step 4: Get the result table of the query
DataTable queryResultTable = RDFQueryEngine.CombineTables(this.PatternGroupResultTables.Values.ToList(), false);
//Step 5: Describe the terms from the result table
DataTable describeResultTable = new DataTable(this.ToString());
if (datasource.IsFederation())
{
#region TrueFederations
foreach (var store in (RDFFederation)datasource)
{
describeResultTable.Merge(RDFQueryEngine.DescribeTerms(this, store, queryResultTable), true, MissingSchemaAction.Add);
}
#endregion
}
else
{
describeResultTable = RDFQueryEngine.DescribeTerms(this, datasource, queryResultTable);
}
//Step 6: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFQueryEngine.ApplyModifiers(this, describeResultTable);
}
else
{
//In this case the only chance to proceed is to have resources in the describe terms,
//which will be used to search for S-P-O data. Variables are ignored in this scenario.
if (this.DescribeTerms.Any(dt => dt is RDFResource))
{
//Step 1: Describe the terms from the result table
DataTable describeResultTable = new DataTable(this.ToString());
if (datasource.IsFederation())
{
#region TrueFederations
foreach (var store in (RDFFederation)datasource)
{
describeResultTable.Merge(RDFQueryEngine.DescribeTerms(this, store, new DataTable()), true, MissingSchemaAction.Add);
}
#endregion
}
else
{
describeResultTable = RDFQueryEngine.DescribeTerms(this, datasource, new DataTable());
}
//Step 2: Apply the modifiers of the query to the result table
describeResult.DescribeResults = RDFQueryEngine.ApplyModifiers(this, describeResultTable);
}
}
return(describeResult);
}