org.apache.hadoop.hive.ql.exec
Class ExprNodeColumnEvaluator

java.lang.Object
  extended by org.apache.hadoop.hive.ql.exec.ExprNodeEvaluator
      extended by org.apache.hadoop.hive.ql.exec.ExprNodeColumnEvaluator

public class ExprNodeColumnEvaluator
extends ExprNodeEvaluator

This evaluator gets the column from the row object.


Field Summary
protected  ExprNodeColumnDesc expr
           
 
Constructor Summary
ExprNodeColumnEvaluator(ExprNodeColumnDesc expr)
           
 
Method Summary
 Object evaluate(Object row)
          Evaluate the expression given the row.
 ObjectInspector initialize(ObjectInspector rowInspector)
          Initialize should be called once and only once.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

expr

protected ExprNodeColumnDesc expr
Constructor Detail

ExprNodeColumnEvaluator

public ExprNodeColumnEvaluator(ExprNodeColumnDesc expr)
Method Detail

initialize

public ObjectInspector initialize(ObjectInspector rowInspector)
                           throws HiveException
Description copied from class: ExprNodeEvaluator
Initialize should be called once and only once. Return the ObjectInspector for the return value, given the rowInspector.

Specified by:
initialize in class ExprNodeEvaluator
Throws:
HiveException

evaluate

public Object evaluate(Object row)
                throws HiveException
Description copied from class: ExprNodeEvaluator
Evaluate the expression given the row. This method should use the rowInspector passed in from initialize to inspect the row object. The return value will be inspected by the return value of initialize.

Specified by:
evaluate in class ExprNodeEvaluator
Throws:
HiveException


Copyright © 2011 The Apache Software Foundation