org.castor.cpa.persistence.sql.query.condition
Class IsNullPredicate

java.lang.Object
  org.castor.cpa.persistence.sql.query.QueryObject
      org.castor.cpa.persistence.sql.query.condition.Condition
          org.castor.cpa.persistence.sql.query.condition.Predicate
              org.castor.cpa.persistence.sql.query.condition.IsNullPredicate

public final class IsNullPredicate
extends Predicate

Predicate that checks expressions for being null or not null.

Version:

$Revision$ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $

Author:

Ahmad Hassan, Ralf Joachim

Constructor Summary

IsNullPredicate(Expression expression)
Construct a predicate that checks the given expression for being null.

IsNullPredicate(Expression expression, boolean evaluateTo)
Construct a predicate that checks the given expression for being null.

Method Summary

void	toString(QueryContext ctx) Append a string representation of the object to the given QueryContext.

Methods inherited from class org.castor.cpa.persistence.sql.query.condition.Predicate

evaluateTo, expression, not

Methods inherited from class org.castor.cpa.persistence.sql.query.condition.Condition

and, or

Methods inherited from class org.castor.cpa.persistence.sql.query.QueryObject

toString

Methods inherited from class java.lang.Object

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

Constructor Detail

IsNullPredicate

public IsNullPredicate(Expression expression)

Construct a predicate that checks the given expression for being null.

Parameters:

expression - Expression to check for null.

IsNullPredicate

public IsNullPredicate(Expression expression,
                       boolean evaluateTo)

Construct a predicate that checks the given expression for being null.

Parameters:

expression - Expression to check for null.

evaluateTo - What is the expected result of the evaluation?

Method Detail

toString

public void toString(QueryContext ctx)

Description copied from class: QueryObject

Append a string representation of the object to the given QueryContext. In general, this toString method appends a string that "textually represents" this object. The result should be a string in valid SQL syntax. It is required that all subclasses override this method.

Specified by:

toString in class QueryObject

Parameters:

ctx - QueryContext to append the string representation of the object to.