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Java > Open Source Codes > com > db4o > test > CollectionSubQuery


1 /* Copyright (C) 2004 - 2006 db4objects Inc. http://www.db4o.com
2
3 This file is part of the db4o open source object database.
4
5 db4o is free software; you can redistribute it and/or modify it under
6 the terms of version 2 of the GNU General Public License as published
7 by the Free Software Foundation and as clarified by db4objects' GPL
8 interpretation policy, available at
9 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 CollectionSubQuery {
29     private final static String JavaDoc ID="X";
30     
31     public static class Data {
32         public String JavaDoc id;
33
34         public Data(String JavaDoc id) {
35             this.id = id;
36         }
37     }
38     
39     public List list;
40     
41     public void storeOne(){
42         this.list=new ArrayList();
43         this.list.add(new Data(ID));
44     }
45     
46     public void test(){
47         Query q = Test.query();
48         q.constrain(CollectionSubQuery.class);
49         Query sub=q.descend("list");
50         // Commenting out this constraint doesn't effect behavior
51 sub.constrain(Data.class);
52         // If this subsub constraint is commented out, the result
53 // contains a Data instance as expected. With this constraint,
54 // we get the containing ArrayList.
55 Query subsub=sub.descend("id");
56         subsub.constrain(ID);
57         ObjectSet result=sub.execute();
58         Test.ensure(result.size()==1);
59         Test.ensure(result.next().getClass()==Data.class);
60     }
61     
62     public static void main(String JavaDoc[] args) {
63         AllTests.run(CollectionSubQuery.class);
64     }
65 }
66
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