Package org.eclipse.rdf4j.query.algebra

Class Group

java.lang.Object

org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

org.eclipse.rdf4j.query.algebra.UnaryTupleOperator

org.eclipse.rdf4j.query.algebra.Group

All Implemented Interfaces:

Serializable, Cloneable, QueryModelNode, TupleExpr, VariableScopeChange

public class Group
extends UnaryTupleOperator

A tuple operator that groups tuples that have a specific set of equivalent variable bindings, and that can apply aggregate functions on the grouped results.

Author:

David Huynh, Arjohn Kampman

See Also:

• Serialized Form

Field Summary

Fields inherited from class org.eclipse.rdf4j.query.algebra.UnaryTupleOperator

arg

Constructor Summary

Constructors

Constructor	Description
Group()
Group(TupleExpr arg)
Group(TupleExpr arg, Iterable<String> groupBindingNames)
Group(TupleExpr arg, Iterable<String> groupBindingNames, Iterable<GroupElem> groupElements)

Method Summary

Modifier and Type	Method	Description
void	addGroupBindingName(String bindingName)
void	addGroupElement(GroupElem groupElem)
Group	clone()	Returns a (deep) clone of this query model node.
boolean	equals(Object other)	Returns true if this query model node and its children are recursively equal to o and its children.
Set<String>	getAggregateBindingNames()
Set<String>	getAssuredBindingNames()	Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.
Set<String>	getBindingNames()	Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.
Set<String>	getGroupBindingNames()
List<GroupElem>	getGroupElements()
String	getSignature()	Default implementation of QueryModelNode.getSignature() that prints the name of the node's class.
int	hashCode()
void	replaceChildNode(QueryModelNode current, QueryModelNode replacement)	Replaces one of the child nodes with a new node.
void	setGroupBindingNames(Iterable<String> bindingNames)
void	setGroupBindingNames(List<String> bindingNames)
void	setGroupElements(Iterable<GroupElem> elements)
<X extends Exception> void	visit(QueryModelVisitor<X> visitor)	Visits this node.
<X extends Exception> void	visitChildren(QueryModelVisitor<X> visitor)	Visits the children of this node.

Methods inherited from class org.eclipse.rdf4j.query.algebra.UnaryTupleOperator

getArg, getOrder, getSupportedOrders, setArg, setOrder

Methods inherited from class org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

getCardinality, getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getTotalTimeNanosActual, isCardinalitySet, isVariableScopeChange, nullEquals, replaceNodeInList, replaceWith, resetCardinality, setCardinality, setCostEstimate, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, setVariableScopeChange, shouldCacheCardinality, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.eclipse.rdf4j.query.algebra.QueryModelNode

getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getTotalTimeNanosActual, replaceWith, setCostEstimate, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, toString

Constructor Details

Group

public Group()

Group

public Group(TupleExpr arg)

Group

public Group(TupleExpr arg,
 Iterable<String> groupBindingNames)

Group

public Group(TupleExpr arg,
 Iterable<String> groupBindingNames,
 Iterable<GroupElem> groupElements)

Method Details

getGroupBindingNames

public Set<String> getGroupBindingNames()

addGroupBindingName

public void addGroupBindingName(String bindingName)

setGroupBindingNames

public void setGroupBindingNames(List<String> bindingNames)

setGroupBindingNames

public void setGroupBindingNames(Iterable<String> bindingNames)

getGroupElements

public List<GroupElem> getGroupElements()

addGroupElement

public void addGroupElement(GroupElem groupElem)

setGroupElements

public void setGroupElements(Iterable<GroupElem> elements)

getAggregateBindingNames

public Set<String> getAggregateBindingNames()

getBindingNames

public Set<String> getBindingNames()

Description copied from interface: TupleExpr

Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.

Specified by:

getBindingNames in interface TupleExpr

Overrides:

getBindingNames in class UnaryTupleOperator

Returns:

A set of binding names.

getAssuredBindingNames

public Set<String> getAssuredBindingNames()

Description copied from interface: TupleExpr

Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.

Specified by:

getAssuredBindingNames in interface TupleExpr

Overrides:

getAssuredBindingNames in class UnaryTupleOperator

Returns:

A set of binding names.

visit

public <X extends Exception> void visit(QueryModelVisitor<X> visitor)
                                 throws X

Description copied from interface: QueryModelNode

Visits this node. The node reports itself to the visitor with the proper runtime type.

Throws:

X

visitChildren

public <X extends Exception> void visitChildren(QueryModelVisitor<X> visitor)
                                         throws X

Description copied from interface: QueryModelNode

Visits the children of this node. The node calls QueryModelNode.visit(QueryModelVisitor) on all of its child nodes.

Specified by:

visitChildren in interface QueryModelNode

Overrides:

visitChildren in class UnaryTupleOperator

Throws:

X

replaceChildNode

public void replaceChildNode(QueryModelNode current,
 QueryModelNode replacement)

Description copied from interface: QueryModelNode

Replaces one of the child nodes with a new node.

Specified by:

replaceChildNode in interface QueryModelNode

Overrides:

replaceChildNode in class UnaryTupleOperator

Parameters:

current - The current child node.

replacement - The new child node.

equals

public boolean equals(Object other)

Description copied from interface: QueryModelNode

Returns true if this query model node and its children are recursively equal to o and its children.

Specified by:

equals in interface QueryModelNode

Overrides:

equals in class UnaryTupleOperator

hashCode

public int hashCode()

Overrides:

hashCode in class UnaryTupleOperator

clone

public Group clone()

Description copied from interface: QueryModelNode

Returns a (deep) clone of this query model node. This method recursively clones the entire node tree, starting from this nodes.

Specified by:

clone in interface QueryModelNode

Specified by:

clone in interface TupleExpr

Overrides:

clone in class UnaryTupleOperator

Returns:

A deep clone of this query model node.

getSignature

public String getSignature()

Description copied from class: AbstractQueryModelNode

Default implementation of QueryModelNode.getSignature() that prints the name of the node's class.

Specified by:

getSignature in interface QueryModelNode

Overrides:

getSignature in class AbstractQueryModelNode

Returns:

The node's signature, e.g. SLICE (offset=10, limit=10).