de.fuberlin.wiwiss.d2rq.expr
Class Expression

java.lang.Object
  extended by de.fuberlin.wiwiss.d2rq.expr.Expression
Direct Known Subclasses:
AttributeExpr, BinaryOperator, BooleanToIntegerCaseExpression, Concatenation, Conjunction, Constant, Disjunction, Equality, Negation, NotNull, SQLExpression, UnaryMinus

public abstract class Expression
extends Object

A SQL expression.

Author:
Richard Cyganiak (richard@cyganiak.de)

Field Summary
static Expression FALSE
           
static Expression TRUE
           
 
Constructor Summary
Expression()
           
 
Method Summary
 Expression and(Expression other)
           
abstract  Set<Attribute> attributes()
           
abstract  boolean isFalse()
           
abstract  boolean isTrue()
           
 Expression or(Expression other)
           
abstract  Expression renameAttributes(ColumnRenamer columnRenamer)
           
abstract  String toSQL(ConnectedDB database, AliasMap aliases)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

TRUE

public static final Expression TRUE

FALSE

public static final Expression FALSE
Constructor Detail

Expression

public Expression()
Method Detail

isTrue

public abstract boolean isTrue()

isFalse

public abstract boolean isFalse()

attributes

public abstract Set<Attribute> attributes()

renameAttributes

public abstract Expression renameAttributes(ColumnRenamer columnRenamer)

toSQL

public abstract String toSQL(ConnectedDB database,
                             AliasMap aliases)

and

public Expression and(Expression other)

or

public Expression or(Expression other)