de.fuberlin.wiwiss.d2rq.algebra
Class Expression

java.lang.Object
  extended by de.fuberlin.wiwiss.d2rq.algebra.Expression

public class Expression
extends Object

An SQL expression. TODO: Shouldn't call to SQL so much

Version:
$Id: Expression.java,v 1.6 2006/09/15 20:38:05 cyganiak Exp $
Author:
Richard Cyganiak (richard@cyganiak.de)

Field Summary
static Expression FALSE
           
static Expression TRUE
           
 
Constructor Summary
Expression(List expressions)
           
Expression(String expression)
           
 
Method Summary
 Expression and(Expression other)
           
 Set columns()
           
 boolean equals(Object other)
          An expression equals another expression iff their SQL strings are identical.
 int hashCode()
           
 boolean isTrue()
           
 Expression renameColumns(ColumnRenamer columnRenamer)
           
 String toSQL(ConnectedDB database)
           
 String toString()
           
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

TRUE

public static final Expression TRUE

FALSE

public static final Expression FALSE
Constructor Detail

Expression

public Expression(String expression)

Expression

public Expression(List expressions)
Method Detail

isTrue

public boolean isTrue()

columns

public Set columns()

renameColumns

public Expression renameColumns(ColumnRenamer columnRenamer)

and

public Expression and(Expression other)

toSQL

public String toSQL(ConnectedDB database)

toString

public String toString()
Overrides:
toString in class Object

equals

public boolean equals(Object other)
An expression equals another expression iff their SQL strings are identical.

Overrides:
equals in class Object

hashCode

public int hashCode()
Overrides:
hashCode in class Object