01: /* Copyright (C) 2004 - 2007 db4objects Inc. http://www.db4o.com
02:
03: This file is part of the db4o open source object database.
04:
05: db4o is free software; you can redistribute it and/or modify it under
06: the terms of version 2 of the GNU General Public License as published
07: by the Free Software Foundation and as clarified by db4objects' GPL
08: interpretation policy, available at
09: http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
10: Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
11: Suite 350, San Mateo, CA 94403, USA.
12:
13: db4o is distributed in the hope that it will be useful, but WITHOUT ANY
14: WARRANTY; without even the implied warranty of MERCHANTABILITY or
15: FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16: for more details.
17:
18: You should have received a copy of the GNU General Public License along
19: with this program; if not, write to the Free Software Foundation, Inc.,
20: 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21: package com.db4o.test;
22:
23: import java.util.*;
24:
25: import com.db4o.*;
26: import com.db4o.query.*;
27:
28: public class SelectDistinct {
29:
30: public String name;
31:
32: public SelectDistinct() {
33: }
34:
35: public SelectDistinct(String name) {
36: this .name = name;
37: }
38:
39: public void store() {
40: Test.store(new SelectDistinct("a"));
41: Test.store(new SelectDistinct("a"));
42: Test.store(new SelectDistinct("a"));
43: Test.store(new SelectDistinct("b"));
44: Test.store(new SelectDistinct("b"));
45: Test.store(new SelectDistinct("c"));
46: Test.store(new SelectDistinct("c"));
47: Test.store(new SelectDistinct("d"));
48: Test.store(new SelectDistinct("e"));
49: }
50:
51: public void test() {
52:
53: String[] expected = new String[] { "a", "b", "c", "d", "e" };
54:
55: Query q = Test.query();
56: q.constrain(SelectDistinct.class);
57: q.constrain(new Evaluation() {
58:
59: private Hashtable ht = new Hashtable();
60:
61: public void evaluate(Candidate candidate) {
62: SelectDistinct sd = (SelectDistinct) candidate
63: .getObject();
64: boolean isDistinct = ht.get(sd.name) == null;
65: candidate.include(isDistinct);
66: if (isDistinct) {
67: ht.put(sd.name, new Object());
68: }
69:
70: }
71: });
72:
73: ObjectSet objectSet = q.execute();
74: while (objectSet.hasNext()) {
75: SelectDistinct sd = (SelectDistinct) objectSet.next();
76: boolean found = false;
77: for (int i = 0; i < expected.length; i++) {
78: if (sd.name.equals(expected[i])) {
79: expected[i] = null;
80: found = true;
81: break;
82: }
83: }
84: Test.ensure(found);
85: }
86:
87: for (int i = 0; i < expected.length; i++) {
88: Test.ensure(expected[i] == null);
89: }
90: }
91: }
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