org.axiondb.functions

Class NullIfFunction

public class NullIfFunction extends BaseFunction implements ScalarFunction, FunctionFactory

The NULLIF function returns a null value if the arguments are equal, otherwise it returns the value of the first argument.

The result of using NULLIF(e1,e2) is the same as using the expression CASE WHEN e1=e2 THEN NULL ELSE e1 END

Version: $Revision: 1.5 $ $Date: 2005/12/20 18:32:28 $

Author: Ahimanikya Satapathy

Constructor Summary
NullIfFunction()
Method Summary
Objectevaluate(RowDecorator row)
DataTypegetDataType()
booleanisValid()
ConcreteFunctionmakeNewInstance()

Constructor Detail

NullIfFunction

public NullIfFunction()

Method Detail

evaluate

public Object evaluate(RowDecorator row)

getDataType

public DataType getDataType()
AnyType

isValid

public boolean isValid()

makeNewInstance

public ConcreteFunction makeNewInstance()