com.metamatrix.query.optimizer.relational
Class AliasGenerator

java.lang.Object
  com.metamatrix.query.sql.LanguageVisitor
      com.metamatrix.query.sql.navigator.AbstractNavigator
          com.metamatrix.query.sql.navigator.PreOrPostOrderNavigator
              com.metamatrix.query.sql.navigator.PreOrderNavigator
                  com.metamatrix.query.optimizer.relational.AliasGenerator

public class AliasGenerator
extends PreOrderNavigator

Adds safe (generated) aliases to the source command The structure is a little convoluted: AliasGenerator - structure navigator, alters the command by adding alias symbols NamingVisitor - changes the output names of Element and Group symbols SQLNamingContext - a hierarchical context for tracking Element and Group names

Field Summary

Fields inherited from class com.metamatrix.query.sql.navigator.PreOrPostOrderNavigator

POST_ORDER, PRE_ORDER

Constructor Summary

AliasGenerator(boolean aliasGroups)

Method Summary

void	visit(ExistsCriteria obj)
void	visit(OrderBy obj)
void	visit(Query obj) visit the query in definition order
void	visit(Reference obj)
void	visit(ScalarSubquery obj)
void	visit(Select obj)
void	visit(SetQuery obj) visit the branches other than the first with individual naming contexts Aliases are being added in all cases, even though they may only be needed in the order by case.
void	visit(SubqueryCompareCriteria obj)
void	visit(SubqueryFromClause obj)
void	visit(SubquerySetCriteria obj)
void	visit(UnaryFromClause obj)

Methods inherited from class com.metamatrix.query.sql.navigator.PreOrderNavigator

doVisit

Methods inherited from class com.metamatrix.query.sql.navigator.PreOrPostOrderNavigator

doVisit, postVisitVisitor, preVisitVisitor, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit

Methods inherited from class com.metamatrix.query.sql.navigator.AbstractNavigator

getVisitor, visitNode, visitNodes, visitVisitor

Methods inherited from class com.metamatrix.query.sql.LanguageVisitor

setAbort, shouldAbort, visit

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AliasGenerator

public AliasGenerator(boolean aliasGroups)

Method Detail

visit

public void visit(SetQuery obj)

visit the branches other than the first with individual naming contexts Aliases are being added in all cases, even though they may only be needed in the order by case. Adding the same alias to all branches ensures cross db support (db2 in particular)

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(Select obj)

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(Query obj)

visit the query in definition order

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(SubqueryFromClause obj)

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(UnaryFromClause obj)

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(ScalarSubquery obj)

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(SubqueryCompareCriteria obj)

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(SubquerySetCriteria obj)

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(ExistsCriteria obj)

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(OrderBy obj)

Overrides:

visit in class PreOrPostOrderNavigator

visit

public void visit(Reference obj)

Overrides:

visit in class PreOrPostOrderNavigator