saffron.rel
Class SubqueryFinder

java.lang.Object
  |
  +--openjava.ptree.util.ParseTreeVisitor
        |
        +--openjava.ptree.util.GenericVisitor
              |
              +--saffron.rel.SubqueryFinder

class SubqueryFinder

extends GenericVisitor

Field Summary

(package private) QueryInfo

queryInfo

Constructor Summary

(package private)

SubqueryFinder(QueryInfo queryInfo)

Method Summary

void	visit(BinaryExpression p)
void	visit(UnaryExpression p) Replaces an exists expression.

Methods inherited from class openjava.ptree.util.GenericVisitor

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, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visit, visitGeneric

Methods inherited from class openjava.ptree.util.ParseTreeVisitor

visit

Methods inherited from class java.lang.Object

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

Field Detail

queryInfo

QueryInfo queryInfo

Constructor Detail

SubqueryFinder

SubqueryFinder(QueryInfo queryInfo)

Method Detail

visit

public void visit(BinaryExpression p)
           throws ParseTreeException

Overrides:

visit in class GenericVisitor

ParseTreeException

visit

public void visit(UnaryExpression p)
           throws ParseTreeException

Replaces an exists expression. For example,

select from dept
 where dept.state.equals("CA") && exists (
	   select from emp where emp.deptno == dept.deptno)

becomes

select from dept left join (
		select distinct true from (
			select from emp where emp.deptno == dept.deptno)) as test
 where dept.state.equals("CA") && test

Overrides:

visit in class GenericVisitor

ParseTreeException