org.apache.derby.impl.sql.compile
Class ReplaceAggregatesWithCRVisitor

java.lang.Object
  extended by org.apache.derby.impl.sql.compile.ReplaceAggregatesWithCRVisitor
All Implemented Interfaces:
Visitor

public class ReplaceAggregatesWithCRVisitor
extends java.lang.Object
implements Visitor

Replace all aggregates with result columns.


Field Summary
private  ResultColumnList rcl
           
private  java.lang.Class skipOverClass
           
private  int tableNumber
           
 
Constructor Summary
ReplaceAggregatesWithCRVisitor(ResultColumnList rcl, java.lang.Class nodeToSkip)
          Replace all aggregates with column references.
ReplaceAggregatesWithCRVisitor(ResultColumnList rcl, int tableNumber)
          Replace all aggregates with column references.
ReplaceAggregatesWithCRVisitor(ResultColumnList rcl, int tableNumber, java.lang.Class skipOverClass)
           
 
Method Summary
 boolean skipChildren(Visitable node)
          Don't visit childen under the skipOverClass node, if it isn't null.
 boolean stopTraversal()
          Method that is called to see if query tree traversal should be stopped before visiting all nodes.
 Visitable visit(Visitable node)
          Don't do anything unless we have an aggregate node.
 boolean visitChildrenFirst(Visitable node)
          Method that is called to see if visit() should be called on the children of node before it is called on node itself.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

rcl

private ResultColumnList rcl

skipOverClass

private java.lang.Class skipOverClass

tableNumber

private int tableNumber
Constructor Detail

ReplaceAggregatesWithCRVisitor

public ReplaceAggregatesWithCRVisitor(ResultColumnList rcl,
                                      int tableNumber)
Replace all aggregates with column references. Add the reference to the RCL. Delegates most work to AggregateNode.replaceAggregatesWithColumnReferences(rcl, tableNumber).

Parameters:
rcl - the result column list
tableNumber - The tableNumber for the new CRs

ReplaceAggregatesWithCRVisitor

public ReplaceAggregatesWithCRVisitor(ResultColumnList rcl,
                                      int tableNumber,
                                      java.lang.Class skipOverClass)

ReplaceAggregatesWithCRVisitor

public ReplaceAggregatesWithCRVisitor(ResultColumnList rcl,
                                      java.lang.Class nodeToSkip)
Replace all aggregates with column references. Add the reference to the RCL. Delegates most work to AggregateNode.replaceAggregatesWithColumnReferences(rcl). Doesn't traverse below the passed in class.

Parameters:
rcl - the result column list
nodeToSkip - don't examine anything below nodeToSkip
Method Detail

visit

public Visitable visit(Visitable node)
                throws StandardException
Don't do anything unless we have an aggregate node.

Specified by:
visit in interface Visitor
Parameters:
node - the node to process
Returns:
me
Throws:
StandardException - on error

skipChildren

public boolean skipChildren(Visitable node)
Don't visit childen under the skipOverClass node, if it isn't null.

Specified by:
skipChildren in interface Visitor
Parameters:
node - the node to process
Returns:
true/false

visitChildrenFirst

public boolean visitChildrenFirst(Visitable node)
Description copied from interface: Visitor
Method that is called to see if visit() should be called on the children of node before it is called on node itself. If this method always returns true, the visitor will walk the tree bottom-up. If it always returns false, the tree is visited top-down.

Specified by:
visitChildrenFirst in interface Visitor
Parameters:
node - the top node of a sub-tree about to be visited
Returns:
true if node's children should be visited before node, false otherwise

stopTraversal

public boolean stopTraversal()
Description copied from interface: Visitor
Method that is called to see if query tree traversal should be stopped before visiting all nodes. Useful for short circuiting traversal if we already know we are done.

Specified by:
stopTraversal in interface Visitor
Returns:
true/false

Built on Thu 2011-03-10 11:54:14+0000, from revision ???

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