org.apache.flink.table.planner.functions.aggfunctions

Class ListAggWithRetractAggFunction

java.lang.Object

org.apache.flink.table.functions.UserDefinedFunction

org.apache.flink.table.functions.UserDefinedAggregateFunction<T,ACC>

org.apache.flink.table.functions.AggregateFunction<StringData,ListAggWithRetractAggFunction.ListAggWithRetractAccumulator>

org.apache.flink.table.planner.functions.aggfunctions.ListAggWithRetractAggFunction

All Implemented Interfaces:

Serializable, FunctionDefinition

public final class ListAggWithRetractAggFunction
extends AggregateFunction<StringData,ListAggWithRetractAggFunction.ListAggWithRetractAccumulator>

built-in listagg with retraction aggregate function.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ListAggWithRetractAggFunction.ListAggWithRetractAccumulator The initial accumulator for listagg with retraction aggregate function.

Constructor Summary

Constructors

Constructor and Description
ListAggWithRetractAggFunction()

Method Summary

Modifier and Type	Method and Description
void	accumulate(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc, StringData value)
ListAggWithRetractAggFunction.ListAggWithRetractAccumulator	createAccumulator() Creates and initializes the accumulator for this UserDefinedAggregateFunction.
TypeInformation<ListAggWithRetractAggFunction.ListAggWithRetractAccumulator>	getAccumulatorType() Returns the TypeInformation of the UserDefinedAggregateFunction's accumulator.
TypeInformation<StringData>	getResultType() Returns the TypeInformation of the UserDefinedAggregateFunction's result.
StringData	getValue(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc) Called every time when an aggregation result should be materialized.
void	merge(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc, Iterable<ListAggWithRetractAggFunction.ListAggWithRetractAccumulator> its)
void	resetAccumulator(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc)
void	retract(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc, StringData value)

Methods inherited from class org.apache.flink.table.functions.AggregateFunction

getKind, getRequirements, getTypeInference, requiresOver

Methods inherited from class org.apache.flink.table.functions.UserDefinedFunction

close, functionIdentifier, open, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.table.functions.FunctionDefinition

isDeterministic

Constructor Detail

ListAggWithRetractAggFunction

public ListAggWithRetractAggFunction()

Method Detail

getResultType

public TypeInformation<StringData> getResultType()

Description copied from class: UserDefinedAggregateFunction

Returns the TypeInformation of the UserDefinedAggregateFunction's result.

Overrides:

getResultType in class UserDefinedAggregateFunction<StringData,ListAggWithRetractAggFunction.ListAggWithRetractAccumulator>

Returns:

The TypeInformation of the UserDefinedAggregateFunction's result or null if the result type should be automatically inferred.

getAccumulatorType

public TypeInformation<ListAggWithRetractAggFunction.ListAggWithRetractAccumulator> getAccumulatorType()

Description copied from class: UserDefinedAggregateFunction

Returns the TypeInformation of the UserDefinedAggregateFunction's accumulator.

Overrides:

getAccumulatorType in class UserDefinedAggregateFunction<StringData,ListAggWithRetractAggFunction.ListAggWithRetractAccumulator>

Returns:

The TypeInformation of the UserDefinedAggregateFunction's accumulator or null if the accumulator type should be automatically inferred.

createAccumulator

public ListAggWithRetractAggFunction.ListAggWithRetractAccumulator createAccumulator()

Description copied from class: UserDefinedAggregateFunction

Creates and initializes the accumulator for this UserDefinedAggregateFunction. The accumulator is used to keep the aggregated values which are needed to compute an aggregation result.

Specified by:

createAccumulator in class UserDefinedAggregateFunction<StringData,ListAggWithRetractAggFunction.ListAggWithRetractAccumulator>

Returns:

the accumulator with the initial value

accumulate

public void accumulate(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc,
                       StringData value)
                throws Exception

Throws:

Exception

retract

public void retract(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc,
                    StringData value)
             throws Exception

Throws:

Exception

merge

public void merge(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc,
                  Iterable<ListAggWithRetractAggFunction.ListAggWithRetractAccumulator> its)
           throws Exception

Throws:

Exception

getValue

public StringData getValue(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc)

Description copied from class: AggregateFunction

Called every time when an aggregation result should be materialized. The returned value could be either an early and incomplete result (periodically emitted as data arrive) or the final result of the aggregation.

Specified by:

getValue in class AggregateFunction<StringData,ListAggWithRetractAggFunction.ListAggWithRetractAccumulator>

Parameters:

acc - the accumulator which contains the current aggregated results

Returns:

the aggregation result

resetAccumulator

public void resetAccumulator(ListAggWithRetractAggFunction.ListAggWithRetractAccumulator acc)