CountAggregateDefinition
, MaxMinAggregateDefinition
, SumAvgAggregateDefinition
, UserAggregateDefinition
interface AggregateDefinition
TypeDescriptor
Modifier and Type | Method | Description |
---|---|---|
DataTypeDescriptor |
getAggregator(DataTypeDescriptor inputType,
java.lang.StringBuffer aggregatorClassName) |
Get the aggregator that performs the aggregation on the
input datatype at execution time.
|
DataTypeDescriptor getAggregator(DataTypeDescriptor inputType, java.lang.StringBuffer aggregatorClassName) throws StandardException
The aggregator class must implement a zero argument constructor. The aggregator class can be the same class as the AggregateDefinition if it implements both interfaces.
The result datatype may be the same as the input datatype or a different datatype. To create your own type descriptor to return to this method, see com.ibm.db2j.types.TypeFactory.
inputType
- the input type descriptoraggregatorClassName
- output parameter, filled in
with the class name that implements com.ibm.db2j.aggregates.AggregatorStandardException
TypeDescriptor
Apache Derby V10.14 Internals - Copyright © 2004,2018 The Apache Software Foundation. All Rights Reserved.