com.metamatrix.query.sql.symbol
Class Reference

java.lang.Object
  com.metamatrix.query.sql.symbol.Reference

All Implemented Interfaces:

LanguageObject, Expression, java.io.Serializable, java.lang.Cloneable

public class Reference
extends java.lang.Object
implements Expression

This class represents a reference within a SQL statement to some other source of data. This reference may resolve to many different values during evaluation. For any particular bound value, it is treated as a constant.

See Also:

Serialized Form

Constructor Summary

Reference(int refIndex)
Constructor for Reference.

Reference(int refIndex, Expression expression)
Constructor for Reference.

Method Summary

void	acceptVisitor(LanguageVisitor visitor) Method for accepting a visitor.
java.lang.Object	clone() Implement clone to make objects cloneable.
boolean	equals(java.lang.Object obj) Compare this constant to another constant for equality.
java.util.Map	getDataElements()
Expression	getExpression()
int	getIndex()
java.util.List	getTuple()
java.lang.Class	getType() Get the return type of this expression.
java.lang.Object	getValue(LookupEvaluator dataMgr, CommandContext context)
int	hashCode() Define hash code to be that of the underlying object to make it stable.
boolean	isCorrelated()
boolean	isPositional()
boolean	isResolved() Return true if expression has been fully resolved.
void	setCorrelated(boolean correlated)
void	setData(java.util.Map elements, java.util.List tuple) Set value provider for this reference
void	setExpression(Expression expression)
void	setPositional(boolean positional)
void	setValue(java.lang.Object value)
java.lang.String	toString() Return a String representation of this object using SQLStringVisitor.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Reference

public Reference(int refIndex)

Constructor for Reference.

Reference

public Reference(int refIndex,
                 Expression expression)

Constructor for Reference.

Method Detail

isResolved

public boolean isResolved()

Description copied from interface: Expression

Return true if expression has been fully resolved. Typically the QueryResolver component will handle resolution of an expression.

Specified by:

isResolved in interface Expression

Returns:

True if resolved

getIndex

public int getIndex()

setExpression

public void setExpression(Expression expression)

getExpression

public Expression getExpression()

getType

public java.lang.Class getType()

Description copied from interface: Expression

Get the return type of this expression. This method will not necessarily work right before resolution (Expression.isResolved() returns true).

Specified by:

getType in interface Expression

Returns:

Java class name

setData

public void setData(java.util.Map elements,
                    java.util.List tuple)

Set value provider for this reference

Parameters:

provider - Provider of values for this reference

getDataElements

public java.util.Map getDataElements()

getTuple

public java.util.List getTuple()

getValue

public java.lang.Object getValue(LookupEvaluator dataMgr,
                                 CommandContext context)
                          throws ExpressionEvaluationException,
                                 MetaMatrixComponentException

Throws:

ExpressionEvaluationException

MetaMatrixComponentException

acceptVisitor

public void acceptVisitor(LanguageVisitor visitor)

Description copied from interface: LanguageObject

Method for accepting a visitor. It is the responsibility of the language object to call back on the visitor.

Specified by:

acceptVisitor in interface LanguageObject

Parameters:

visitor - Visitor being used

clone

public java.lang.Object clone()

Description copied from interface: LanguageObject

Implement clone to make objects cloneable.

Specified by:

clone in interface LanguageObject

Overrides:

clone in class java.lang.Object

Returns:

Deep clone of this object

See Also:

Object.clone()

equals

public boolean equals(java.lang.Object obj)

Compare this constant to another constant for equality.

Overrides:

equals in class java.lang.Object

Parameters:

obj - Other object

Returns:

True if constants are equal

hashCode

public int hashCode()

Define hash code to be that of the underlying object to make it stable.

Overrides:

hashCode in class java.lang.Object

Returns:

Hash code, based on value

toString

public java.lang.String toString()

Return a String representation of this object using SQLStringVisitor.

Overrides:

toString in class java.lang.Object

Returns:

String representation using SQLStringVisitor

isCorrelated

public boolean isCorrelated()

setCorrelated

public void setCorrelated(boolean correlated)

setValue

public void setValue(java.lang.Object value)

isPositional

public boolean isPositional()

setPositional

public void setPositional(boolean positional)