public class CountFunction extends BaseAggregateFunction implements AggregateFunction, FunctionFactory
COUNT
: an aggregate function returning the number of rows._hash
Constructor and Description |
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CountFunction() |
Modifier and Type | Method and Description |
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java.lang.Object |
evaluate(RowDecoratorIterator rows) |
DataType |
getDataType() |
ConcreteFunction |
makeNewInstance() |
acceptable, evaluate, isDistinct, isValid, setDistinct, setDistinct
addArgument, getArgument, getArgumentCount, setArgument, setVariableContext, toString
getAlias, getLabel, getName, setAlias, setName
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
isValid
addArgument, getAlias, getArgument, getArgumentCount, getName, setAlias, setArgument
evaluate, getLabel, setVariableContext
public ConcreteFunction makeNewInstance()
makeNewInstance
in interface FunctionFactory
public DataType getDataType()
getDataType
in interface Selectable
getDataType
in class BaseFunction
public java.lang.Object evaluate(RowDecoratorIterator rows) throws AxionException
evaluate
in interface AggregateFunction
AxionException