Class Select

Represents the Selection step of Query Evaluation.
Inheritance
System.Object
Select
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
Namespace: VDS.RDF.Query.Algebra
Assembly: dotNetRDF.dll
Syntax
public class Select : IUnaryOperator, ISparqlAlgebra
Remarks
Selection trims variables from the Multiset that are not needed in the final output.

Constructors

| Improve this Doc View Source

Select(ISparqlAlgebra, Boolean, IEnumerable<SparqlVariable>)

Creates a new Select.
Declaration
public Select(ISparqlAlgebra pattern, bool selectAll, IEnumerable<SparqlVariable> variables)
Parameters
Type Name Description
ISparqlAlgebra pattern Inner Pattern.
System.Boolean selectAll Whether we are selecting all variables.
System.Collections.Generic.IEnumerable<SparqlVariable> variables Variables to Select.

Properties

| Improve this Doc View Source

FixedVariables

Gets the enumeration of fixed variables in the algebra i.e. variables that are guaranteed to have a bound value.
Declaration
public IEnumerable<string> FixedVariables { get; }
Property Value
Type Description
System.Collections.Generic.IEnumerable<System.String>
| Improve this Doc View Source

FloatingVariables

Gets the enumeration of floating variables in the algebra i.e. variables that are not guaranteed to have a bound value.
Declaration
public IEnumerable<string> FloatingVariables { get; }
Property Value
Type Description
System.Collections.Generic.IEnumerable<System.String>
| Improve this Doc View Source

InnerAlgebra

Gets the Inner Algebra.
Declaration
public ISparqlAlgebra InnerAlgebra { get; }
Property Value
Type Description
ISparqlAlgebra
| Improve this Doc View Source

IsSelectAll

Does this operator select all variables?.
Declaration
public bool IsSelectAll { get; }
Property Value
Type Description
System.Boolean
| Improve this Doc View Source

SparqlVariables

Gets the SPARQL Variables used.
Declaration
public IEnumerable<SparqlVariable> SparqlVariables { get; }
Property Value
Type Description
System.Collections.Generic.IEnumerable<SparqlVariable>
Remarks
If the Query supplied in the SparqlEvaluationContext is non-null then it's Variables are used rather than these.
| Improve this Doc View Source

Variables

Gets the Variables used in the Algebra.
Declaration
public IEnumerable<string> Variables { get; }
Property Value
Type Description
System.Collections.Generic.IEnumerable<System.String>

Methods

| Improve this Doc View Source

Evaluate(SparqlEvaluationContext)

Trims the Results of evaluating the inner pattern to remove Variables which are not Result Variables.
Declaration
public BaseMultiset Evaluate(SparqlEvaluationContext context)
Parameters
Type Name Description
SparqlEvaluationContext context Evaluation Context.
Returns
Type Description
BaseMultiset
| Improve this Doc View Source

ToGraphPattern()

Throws an error as a Select() cannot be converted back to a Graph Pattern.
Declaration
public GraphPattern ToGraphPattern()
Returns
Type Description
GraphPattern
Exceptions
Type Condition
System.NotSupportedException Thrown since a Select() cannot be converted back to a Graph Pattern.
| Improve this Doc View Source

ToQuery()

Converts the Algebra back to a SPARQL Query.
Declaration
public SparqlQuery ToQuery()
Returns
Type Description
SparqlQuery
| Improve this Doc View Source

ToString()

Gets the String representation of the Algebra.
Declaration
public override string ToString()
Returns
Type Description
System.String
Overrides
System.Object.ToString()
| Improve this Doc View Source

Transform(IAlgebraOptimiser)

Transforms the Inner Algebra using the given Optimiser.
Declaration
public ISparqlAlgebra Transform(IAlgebraOptimiser optimiser)
Parameters
Type Name Description
IAlgebraOptimiser optimiser Optimiser.
Returns
Type Description
ISparqlAlgebra

Implements

Extension Methods