com.metamatrix.query.sql.lang
Class ExistsCriteria

java.lang.Object
  com.metamatrix.query.sql.lang.Criteria
      com.metamatrix.query.sql.lang.PredicateCriteria
          com.metamatrix.query.sql.lang.ExistsCriteria

All Implemented Interfaces:

SubqueryContainer, LanguageObject, ContextReference, java.io.Serializable, java.lang.Cloneable

public class ExistsCriteria
extends PredicateCriteria
implements SubqueryContainer, ContextReference

This predicate criteria implements the "exists" predicate, which has a subquery in it. For example, "EXISTS (Select EmployeeID FROM Employees WHERE EmployeeName = 'Smith')".

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.metamatrix.query.sql.lang.PredicateCriteria

PredicateCriteria.Negatable

Constructor Summary

ExistsCriteria()
Default constructor

ExistsCriteria(Command subqueryCommand)

Method Summary

void	acceptVisitor(LanguageVisitor visitor) Method for accepting a visitor.
java.lang.Object	clone() Deep copy of object.
boolean	equals(java.lang.Object obj) Override equals() method.
Command	getCommand() Returns the subquery Command object
java.lang.String	getContextSymbol()
Expression	getValueExpression()
int	hashCode() Get hash code.
void	setCommand(Command subqueryCommand) Sets the subquery Command object

Methods inherited from class com.metamatrix.query.sql.lang.Criteria

combineCriteria, combineCriteria, combineCriteria, separateCriteriaByAnd, toConjunctiveNormalForm, toDisjunctiveNormalForm, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ExistsCriteria

public ExistsCriteria()

Default constructor

ExistsCriteria

public ExistsCriteria(Command subqueryCommand)

Method Detail

getContextSymbol

public java.lang.String getContextSymbol()

Specified by:

getContextSymbol in interface ContextReference

getValueExpression

public Expression getValueExpression()

Specified by:

getValueExpression in interface ContextReference

getCommand

public Command getCommand()

Description copied from interface: SubqueryContainer

Returns the subquery Command object

Specified by:

getCommand in interface SubqueryContainer

Returns:

the subquery Command object

See Also:

com.metamatrix.query.sql.lang.SubqueryCriteria#getCommand()

setCommand

public void setCommand(Command subqueryCommand)

Description copied from interface: SubqueryContainer

Sets the subquery Command object

Specified by:

setCommand in interface SubqueryContainer

Parameters:

subqueryCommand - the subquery Command object

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

hashCode

public int hashCode()

Get hash code. WARNING: The hash code is based on data in the criteria. If data values are changed, the hash code will change - don't hash this object and change values.

Overrides:

hashCode in class java.lang.Object

Returns:

Hash code

equals

public boolean equals(java.lang.Object obj)

Override equals() method.

Overrides:

equals in class java.lang.Object

Parameters:

obj - Other object

Returns:

True if equal

clone

public java.lang.Object clone()

Deep copy of object. The values Iterator of this object will not be cloned - it will be null in the new object (see #setValueIterator setValueIterator}).

Specified by:

clone in interface LanguageObject

Specified by:

clone in class PredicateCriteria

Returns:

Deep copy of object

See Also:

Object.clone()