/// <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.");
}
