org.apache.derby.impl.sql.execute

Class SumAggregator

java.lang.Object

org.apache.derby.impl.sql.execute.SystemAggregator

org.apache.derby.impl.sql.execute.OrderableAggregator

org.apache.derby.impl.sql.execute.SumAggregator

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, Formatable, TypedFormat, ExecAggregator

Direct Known Subclasses:

AvgAggregator

public class SumAggregator
extends OrderableAggregator

Aggregator for SUM(). Defers most of its work to OrderableAggregator.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.derby.impl.sql.execute.OrderableAggregator

value

Constructor Summary

Constructors

Constructor and Description
SumAggregator()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	accumulate(DataValueDescriptor addend) Accumulate
int	getTypeFormatId() Get the formatID which corresponds to this class.
ExecAggregator	newAggregator() Return a new initialized copy of this aggregator, any state set by the setup() method of the original Aggregator must be copied into the new aggregator.
java.lang.String	toString()

Methods inherited from class org.apache.derby.impl.sql.execute.OrderableAggregator

getResult, merge, readExternal, setup, writeExternal

Methods inherited from class org.apache.derby.impl.sql.execute.SystemAggregator

accumulate, didEliminateNulls

Methods inherited from class java.lang.Object

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

Constructor Detail

SumAggregator

public SumAggregator()

Method Detail

accumulate

protected void accumulate(DataValueDescriptor addend)
                   throws StandardException

Accumulate

Specified by:

accumulate in class SystemAggregator

Parameters:

addend - value to be added in

Throws:

StandardException - on error

See Also:

ExecAggregator.accumulate(org.apache.derby.iapi.types.DataValueDescriptor, java.lang.Object)

newAggregator

public ExecAggregator newAggregator()

Description copied from interface: ExecAggregator

Return a new initialized copy of this aggregator, any state set by the setup() method of the original Aggregator must be copied into the new aggregator.

Returns:

ExecAggregator the new aggregator

getTypeFormatId

public int getTypeFormatId()

Get the formatID which corresponds to this class.

Returns:

the formatID of this class

toString

public java.lang.String toString()

Overrides:

toString in class OrderableAggregator