be.SIRAPRISE.typeimplementations

Class AGGREGATE

java.lang.Object

be.SIRAPRISE.typeimplementations.RelationalOperator

be.SIRAPRISE.typeimplementations.AGGREGATE

All Implemented Interfaces:

OperatorGenerator

@OperatorGeneratorCharacteristics(maximumArgumentCount=2,
                                  minimumArgumentCount=2,
                                  name="AGGREGATE",
                                  signature={EXPRESSION,STRING})
 @MonoRelationOperator
public abstract class AGGREGATE
extends RelationalOperator

AGGREGATE

Author:

erwin

Constructor Summary

Constructors

Constructor and Description
AGGREGATE()

Method Summary

Modifier and Type	Method and Description
static Relation	computeAggregate(Relation relation, java.util.Map<NameIdentifier,java.lang.String> expressions)
OperatorImplementation_V0105	getOperatorImplementation(OperatorGeneratorArgument[] args) Gets an implementation instance of the operator.

Methods inherited from class be.SIRAPRISE.typeimplementations.RelationalOperator

getInvocationName, getMaximumArgumentCount, getMinimumArgumentCount, getName, getOperatorGeneratorSignature, isMonoRelationOperator, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AGGREGATE

public AGGREGATE()

Method Detail

computeAggregate

public static Relation computeAggregate(Relation relation,
                                        java.util.Map<NameIdentifier,java.lang.String> expressions)

Parameters:

relation - the relation to be aggregated

expressions - the expressions defining which aggregations to compute, mapped to the attribute names for the respective aggregation results in the relation returned

Returns:

the result of aggregating the given relation according to the given specs

getOperatorImplementation

public OperatorImplementation_V0105 getOperatorImplementation(OperatorGeneratorArgument[] args)

Description copied from interface: OperatorGenerator

Gets an implementation instance of the operator.

Parameters:

args - The arguments from which the instance is to be created. There must be exactly as many arguments as there are elements in the list returned from OperatorGenerator.getOperatorGeneratorSignature(). The correspondence between OperatorGeneratorArgumentType values and OperatorGeneratorArgument types is given in the table below :

correspondence between OperatorGeneratorArgumentType values and OperatorGeneratorArgument types

OperatorGeneratorArgumentType value	OperatorGeneratorArgument type
EXPRESSION	NonScalarOperatorGeneratorExpressionArgument
EXPRESSIONWITHSCOPE	NonScalarOperatorGeneratorExpressionArgument
STRING	NonScalarOperatorGeneratorTextArgument

Returns:

an instance of the operator