001    package org.apache.ojb.broker.query;
002    
003    /* Copyright 2002-2005 The Apache Software Foundation
004     *
005     * Licensed under the Apache License, Version 2.0 (the "License");
006     * you may not use this file except in compliance with the License.
007     * You may obtain a copy of the License at
008     *
009     *     http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    
018    /**
019     * SelectionCriteria for 'is null' and 'is not null'
020     * 
021     * @author <a href="mailto:jbraeuchi@gmx.ch">Jakob Braeuchi</a>
022     * @version $Id: NullCriteria.java,v 1.1 2007-08-24 22:17:36 ewestfal Exp $
023     */
024    public class NullCriteria extends ValueCriteria
025    {
026            NullCriteria(String anAttribute, String aClause, String anAlias)
027            {
028                    super(anAttribute, null, aClause, anAlias);
029            }
030    
031            NullCriteria(String anAttribute, String aClause, UserAlias anAlias)
032            {
033                    super(anAttribute, null, aClause, anAlias);
034            }
035    
036        public String toString()
037        {
038            return getAttribute() + getClause();
039        }
040    
041        /**
042         * @see SelectionCriteria#isBound()
043         */
044        public boolean isBound()
045        {
046            return true;
047        }
048    
049        /**
050         * @see SelectionCriteria#isBindable()
051         */
052        protected boolean isBindable()
053        {
054            return false;
055        }
056    
057    }