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Java > Open Source Codes > org > xquark > extractor > algebra > FormatDateTime


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.algebra;
24
25 import java.sql.Types JavaDoc;
26 import java.util.List JavaDoc;
27
28 import org.xquark.extractor.xfunctions.XfCast;
29 import org.xquark.jdbc.typing.DbType;
30
31
32 /**
33  * Formats top-level projections to retrieve a schema valid output for dates.
34  * Adds a cast to string on top of datetime top projection items.
35  * UNUSED
36  */
37 public final class FormatDateTime {
38
39     private static final String JavaDoc RCSRevision = "$Revision: 1.8 $";
40     private static final String JavaDoc RCSName = "$Name: $";
41
42     public FormatDateTime() {
43     }
44
45     public static void formatDateTimes(Expression algebraTree)
46     {
47         //Trace.enter("FormatDateTime","formatDateTime(Expression algebraTree)");
48 TopLevelProjectsVisitor tlpv = new TopLevelProjectsVisitor();
49         tlpv.reinit();
50         algebraTree.accept(tlpv);
51         List JavaDoc projectList = tlpv.getProjectList();
52         UnOpProject project = null;
53         for (int i = 0; i < projectList.size(); i++) {
54             project = (UnOpProject)projectList.get(i);
55             formatDateTimes(project);
56         }
57         //Trace.exit("FormatDateTime","formatDateTime(Expression algebraTree)");
58 }
59
60     private static void formatDateTimes(UnOpProject project)
61     {
62         //Trace.enter("FormatDateTime","formatDateTime(UnOpProject project)");
63
64         List JavaDoc itemList = project.getItemList();
65         Expression item = null;
66         SqlTypeAtom type = null;
67         DbType stringType = new DbType(Types.CHAR);
68         String JavaDoc itemName = null;
69         for (int i = 0; i < itemList.size(); i++) {
70             item = (Expression)itemList.get(i);
71             type = (SqlTypeAtom)item.getType();
72             if (type.isDataTime()) {
73                 itemName = item.getName();
74                 if (item instanceof RenameItem) {
75                     item = ((RenameItem)item).getOperand();
76                 }
77                 item = new XfCast(item,stringType);
78                 if (null != itemName) {
79                     item = new RenameItem(item, itemName);
80                 }
81                 project.setItem(i, item);
82             }
83         }
84         //Trace.exit("FormatDateTime","formatDateTime(UnOpProject project)");
85 }
86
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96
97 }
98
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