org.teiid.query.function.aggregate
Class AggregateFunction

java.lang.Object
  org.teiid.query.function.aggregate.AggregateFunction

Direct Known Subclasses:

ArrayAgg, ConstantFunction, Count, Max, Min, SortingFilter, StatsFunction, Sum, TextAgg, XMLAgg

public abstract class AggregateFunction
extends java.lang.Object

This represents the interface for an aggregate function. The basic lifecycle is that the AggregateFunction is initialize()'d with the type of the element being aggregated, then addInput() is called for every row in the group, then getResult() is called to retrieve the result.

Constructor Summary

AggregateFunction()

Method Summary

void	addInput(java.util.List<?> tuple)
abstract void	addInputDirect(java.lang.Object input, java.util.List<?> tuple) Called for the element value in every row of a group.
abstract java.lang.Object	getResult() Called after all values have been processed to get the result.
void	initialize(java.lang.Class<?> dataType, java.lang.Class<?> inputType) Called to initialize the function.
abstract void	reset() Called to reset the state of the function.
void	setExpressionIndex(int expressionIndex)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AggregateFunction

public AggregateFunction()

Method Detail

setExpressionIndex

public void setExpressionIndex(int expressionIndex)

initialize

public void initialize(java.lang.Class<?> dataType,
                       java.lang.Class<?> inputType)

Called to initialize the function. In the future this may expand with additional information.

Parameters:

dataType - Data type of element begin aggregated

inputType -

reset

public abstract void reset()

Called to reset the state of the function.

addInput

public void addInput(java.util.List<?> tuple)
              throws TeiidComponentException,
                     TeiidProcessingException

Throws:

TeiidComponentException

TeiidProcessingException

addInputDirect

public abstract void addInputDirect(java.lang.Object input,
                                    java.util.List<?> tuple)
                             throws TeiidComponentException,
                                    TeiidProcessingException

Called for the element value in every row of a group.

Parameters:

input - Input value, may be null

tuple -

Throws:

TeiidProcessingException

TeiidComponentException

getResult

public abstract java.lang.Object getResult()
                                    throws FunctionExecutionException,
                                           ExpressionEvaluationException,
                                           TeiidComponentException,
                                           TeiidProcessingException

Called after all values have been processed to get the result.

Returns:

Result value

Throws:

TeiidProcessingException

FunctionExecutionException

ExpressionEvaluationException

TeiidComponentException