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Java > Open Source Codes > org > xquark > extractor > sql > SqlJoin


1 /*
2  * This file belongs to the XQuark distribution.
3  * Copyright (C) 2003 Universite de Versailles Saint-Quentin.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307.
18  * You can also get it at http://www.gnu.org/licenses/lgpl.html
19  *
20  * For more information on this software, see http://www.xquark.org.
21  */
22
23 package org.xquark.extractor.sql;
24
25 import java.util.ArrayList JavaDoc;
26 import java.util.Iterator JavaDoc;
27 import java.util.List JavaDoc;
28
29 public class SqlJoin extends SqlExpression
30 {
31     private static final String JavaDoc RCSRevision = "$Revision: 1.3 $";
32     private static final String JavaDoc RCSName = "$Name: $";
33
34     protected List JavaDoc _relationList;
35
36     public SqlJoin()
37     {
38         _relationList = new ArrayList JavaDoc();
39     }
40
41     public SqlJoin(List JavaDoc operandList)
42     {
43         setOperandList(operandList);
44     }
45
46     public List JavaDoc getOperandList()
47     {
48         return _relationList;
49     }
50
51     public void setOperandList(List JavaDoc operandList)
52     {
53         _relationList = operandList;
54     }
55     
56     public void addOperand(SqlExpression operand) {
57         _relationList.add(operand);
58     }
59     
60     public String JavaDoc toSql (Context context)
61     {
62         //Trace.enter(this,"toSql(Context context)");
63
64         StringBuffer JavaDoc retVal = new StringBuffer JavaDoc();
65
66         Iterator JavaDoc it = _relationList.iterator();
67         while (it.hasNext()) {
68             SqlExpression relation = (SqlExpression)it.next();
69
70             if (relation instanceof SqlSelect) {
71                 retVal.append('(');
72                 retVal.append(relation.toSql(context));
73                 retVal.append(')');
74             }
75             else {
76                 retVal.append(relation.toSql(context));
77             }
78             retVal.append(", "); // NOTE: not needed anymore since a SqlJoin node exists
79 }
80         retVal.setLength(retVal.length() - 2);
81
82         //Trace.exit(this,"toSql(Context context)");
83 return retVal.toString();
84     }
85 }
86
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