com.hp.hpl.jena.sparql.expr.aggregate
Interface Aggregator

All Known Implementing Classes:

AggAvg, AggAvgDistinct, AggCount, AggCountDistinct, AggCountVar, AggCountVarDistinct, AggGroupConcat, AggGroupConcatDistinct, AggMax, AggMaxDistinct, AggMin, AggMinDistinct, AggNull, AggregatorBase, AggSample, AggSampleDistinct, AggSum, AggSumDistinct

public interface Aggregator

An Aggregator is the processor for the whole result stream. BindingKeys identify which section of a group we're in.

Method Summary

Aggregator	copy(Expr expr)
Aggregator	copyTransform(NodeTransform transform)
Accumulator	createAccumulator() Create an accumulator for this aggregator
boolean	equals(Object other)
Expr	getExpr() Get the expression - may be null (e.g COUNT(*)) ;
Node	getValueEmpty() Value if there are no elements in any group : return null for no result
int	hashCode()
String	key()
String	toPrefixString()

Method Detail

createAccumulator

Accumulator createAccumulator()

Create an accumulator for this aggregator

getValueEmpty

Node getValueEmpty()

Value if there are no elements in any group : return null for no result

toPrefixString

String toPrefixString()

key

String key()

getExpr

Expr getExpr()

Get the expression - may be null (e.g COUNT(*)) ;

copy

Aggregator copy(Expr expr)

copyTransform

Aggregator copyTransform(NodeTransform transform)

hashCode

int hashCode()

Overrides:

hashCode in class Object

equals

boolean equals(Object other)

Overrides:

equals in class Object