Class GroupBy

Represents a Grouping.

Inheritance

object

GroupBy

Implements

IUnaryOperator

ISparqlAlgebra

IVisitable

IProcessable

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: VDS.RDF.Query.Algebra

Assembly: dotNetRdf.dll

Syntax

public class GroupBy : IUnaryOperator, ISparqlAlgebra, IVisitable, IProcessable

Constructors

GroupBy(ISparqlAlgebra, ISparqlGroupBy, IEnumerable<SparqlVariable>)

Creates a new Group By.

Declaration

public GroupBy(ISparqlAlgebra pattern, ISparqlGroupBy grouping, IEnumerable<SparqlVariable> aggregates)

Parameters

Type	Name	Description
ISparqlAlgebra	pattern	Pattern.
ISparqlGroupBy	grouping	Grouping to use.
IEnumerable<SparqlVariable>	aggregates	Aggregates to calculate.

Properties

Aggregates

Gets the Aggregates that will be applied.

Declaration

public IEnumerable<SparqlVariable> Aggregates { get; }

Property Value

Type	Description
IEnumerable<SparqlVariable>

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
IEnumerable<string>

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
IEnumerable<string>

Grouping

Gets the Grouping that is used.

Declaration

public ISparqlGroupBy Grouping { get; }

Property Value

Type	Description
ISparqlGroupBy

Remarks

If the Query supplied in the SparqlEvaluationContext is non-null and has a GROUP BY clause then that is applied rather than the clause with which the GroupBy algebra is instantiated.

InnerAlgebra

Gets the Inner Algebra.

Declaration

public ISparqlAlgebra InnerAlgebra { get; }

Property Value

Type	Description
ISparqlAlgebra

Variables

Gets the Variables used in the Algebra.

Declaration

public IEnumerable<string> Variables { get; }

Property Value

Type	Description
IEnumerable<string>

Methods

Accept<T>(ISparqlAlgebraVisitor<T>)

Accept a simple algebra visitor.

Declaration

public T Accept<T>(ISparqlAlgebraVisitor<T> visitor)

Parameters

Type	Name	Description
ISparqlAlgebraVisitor<T>	visitor	The visitor implementation.

Returns

Type	Description
T

Type Parameters

Name	Description
T	The type returned by the Visit methods of the visitor.

Accept<TResult, TContext>(ISparqlQueryAlgebraProcessor<TResult, TContext>, TContext)

Called by an algebra visitor to process an item by invoking the appropriate method on the processor passed in.

Declaration

public TResult Accept<TResult, TContext>(ISparqlQueryAlgebraProcessor<TResult, TContext> processor, TContext context)

Parameters

Type	Name	Description
ISparqlQueryAlgebraProcessor<TResult, TContext>	processor	The processor to invoke.
TContext	context	The context to pass to the processor.

Returns

Type	Description
TResult	The result of invoking the processor method.

Type Parameters

Name	Description
TResult	The type of result returned by the processor.
TContext	The type of the context object to be provided to the processor.

ToGraphPattern()

Throws an exception since GroupBy() cannot be converted to a Graph Pattern.

Declaration

public GraphPattern ToGraphPattern()

Returns

Type	Description
GraphPattern

Exceptions

Type	Condition
NotSupportedException	Thrown since GroupBy() cannot be converted to a GraphPattern.

ToQuery()

Converts the Algebra back to a SPARQL Query.

Declaration

public SparqlQuery ToQuery()

Returns

Type	Description
SparqlQuery

ToString()

Gets the String representation of the.

Declaration

public override string ToString()

Returns

Type	Description
string

Overrides

object.ToString()

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

IUnaryOperator

ISparqlAlgebra

IVisitable

IProcessable

Extension Methods

Extensions.ToSafeString(object)

Extensions.AsEnumerable<T>(T)