1 /*
2 * $Source$
3 * $Revision$
4 *
5 * Copyright (C) 2000 William Chesters
6 *
7 * Part of Melati (http://melati.org), a framework for the rapid
8 * development of clean, maintainable web applications.
9 *
10 * Melati is free software; Permission is granted to copy, distribute
11 * and/or modify this software under the terms either:
12 *
13 * a) the GNU General Public License as published by the Free Software
14 * Foundation; either version 2 of the License, or (at your option)
15 * any later version,
16 *
17 * or
18 *
19 * b) any version of the Melati Software License, as published
20 * at http://melati.org
21 *
22 * You should have received a copy of the GNU General Public License and
23 * the Melati Software License along with this program;
24 * if not, write to the Free Software Foundation, Inc.,
25 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26 * GNU General Public License and visit http://melati.org to obtain the
27 * Melati Software License.
28 *
29 * Feel free to contact the Developers of Melati (http://melati.org),
30 * if you would like to work out a different arrangement than the options
31 * outlined here. It is our intention to allow Melati to be used by as
32 * wide an audience as possible.
33 *
34 * This program is distributed in the hope that it will be useful,
35 * but WITHOUT ANY WARRANTY; without even the implied warranty of
36 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
37 * GNU General Public License for more details.
38 *
39 * Contact details for copyright holder:
40 *
41 * William Chesters <williamc At paneris.org>
42 * http://paneris.org/~williamc
43 * Obrechtstraat 114, 2517VX Den Haag, The Netherlands
44 */
45
46 package org.melati.poem;
47
48 /**
49 * A cached instance of an SQL <code>count</code> > 0 query.
50 */
51 public class CachedExists extends CachedCount {
52
53 /**
54 * Constructor.
55 *
56 * @param table the Table we are dealing with
57 * @param whereClause SQL snippet
58 * @param otherTables Array of other tables referred to in whereClause, if any
59 */
60 public CachedExists(final Table<?> table,
61 final String whereClause,
62 final Table<?> otherTables[]) {
63 super(table, whereClause, otherTables);
64 }
65
66 /**
67 * @param table the Table we are dealing with
68 * @param whereClause SQL snippet
69 */
70 public CachedExists(final Table<?> table, final String whereClause) {
71 this(table, whereClause, null);
72 }
73
74 /**
75 * @return whether any record match the criteria or not
76 */
77 public boolean exists() {
78 compute();
79 return ((Integer)this.rows.elementAt(0)).intValue() > 0;
80 }
81
82 }