org.datanucleus.query.evaluator.memory
Class NullIfFunctionEvaluator

java.lang.Object
  extended by org.datanucleus.query.evaluator.memory.NullIfFunctionEvaluator
All Implemented Interfaces:
InvocationEvaluator

public class NullIfFunctionEvaluator
extends java.lang.Object
implements InvocationEvaluator

Evaluator for the function NULLIF(numExpr, numExpr2). Returns null if the args are equal, otherwise returns the first arg.


Constructor Summary
NullIfFunctionEvaluator()
           
 
Method Summary
 java.lang.Object evaluate(InvokeExpression expr, java.lang.Object ignored, InMemoryExpressionEvaluator eval)
          Method to evaluate the InvokeExpression, as part of the overall evaluation defined by the InMemoryExpressionEvaluator.
protected  java.lang.Object getValueForArgExpression(Expression argExpr, InMemoryExpressionEvaluator eval)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

NullIfFunctionEvaluator

public NullIfFunctionEvaluator()
Method Detail

evaluate

public java.lang.Object evaluate(InvokeExpression expr,
                                 java.lang.Object ignored,
                                 InMemoryExpressionEvaluator eval)
Description copied from interface: InvocationEvaluator
Method to evaluate the InvokeExpression, as part of the overall evaluation defined by the InMemoryExpressionEvaluator.

Specified by:
evaluate in interface InvocationEvaluator
Parameters:
expr - The expression for invocation
ignored - Value on which we are invoking
eval - The overall evaluator for in-memory
Returns:
The result

getValueForArgExpression

protected java.lang.Object getValueForArgExpression(Expression argExpr,
                                                    InMemoryExpressionEvaluator eval)


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