Package io.deephaven.api.agg

Class LastRowKey

java.lang.Object

io.deephaven.api.agg.LastRowKey

All Implemented Interfaces:

Aggregation

@Immutable
public abstract class LastRowKey
extends Object
implements Aggregation

An aggregation that provides a single output column with the last row key from the input table for each aggregation group in the result.

The primary use case for this aggregation is to allow for a subsequent sort on the output column to order aggregated data by current last occurrence in the input table rather than encounter order.

Nested Class Summary

Nested classes/interfaces inherited from interface io.deephaven.api.agg.Aggregation

Aggregation.Visitor

Constructor Summary

Constructors

Constructor	Description
LastRowKey()

Method Summary

Modifier and Type	Method	Description
abstract ColumnName	column()
static LastRowKey	of(ColumnName name)
static LastRowKey	of(String x)
final <V extends Aggregation.Visitor> V	walk(V visitor)	Glue method to deliver this Aggregation to a AggSpec.Visitor.

Methods inherited from class java.lang.Object

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

Constructor Details

LastRowKey

public LastRowKey()

Method Details

of

public static LastRowKey of(ColumnName name)

of

public static LastRowKey of(String x)

column

@Parameter
public abstract ColumnName column()

walk

public final <V extends Aggregation.Visitor> V walk(V visitor)

Description copied from interface: Aggregation

Glue method to deliver this Aggregation to a AggSpec.Visitor.

Specified by:

walk in interface Aggregation

Parameters:

visitor - The visitor

Returns:

The visitor