1 package org.apache.ojb.broker.query;
2
3 /* Copyright 2002-2005 The Apache Software Foundation
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 /**
19 * SelectionCriteria for [not] exists(sub query)
20 *
21 * @author <a href="mailto:jbraeuchi@gmx.ch">Jakob Braeuchi</a>
22 * @version $Id: ExistsCriteria.java,v 1.1 2007-08-24 22:17:36 ewestfal Exp $
23 */
24 public class ExistsCriteria extends SelectionCriteria
25 {
26 private boolean m_negative = false;
27 /**
28 * Constructor for ExistsCriteria.
29 * @param subQuery
30 * @param negative use negative form
31 */
32 ExistsCriteria(Query subQuery, boolean negative)
33 {
34 super("", subQuery, (String)null);
35 m_negative = negative;
36 }
37
38 /*
39 * @see SelectionCriteria#getClause()
40 */
41 public String getClause()
42 {
43 if (m_negative)
44 {
45 return " NOT EXISTS";
46 }
47 else
48 {
49 return " EXISTS";
50 }
51 }
52 }