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Java > Open Source Codes > smallsql > database > ExpressionInSelect


1 /* =============================================================
2  * SmallSQL : a free Java DBMS library for the Java(tm) platform
3  * =============================================================
4  *
5  * (C) Copyright 2004-2006, by Volker Berlin.
6  *
7  * Project Info: http://www.smallsql.de/
8  *
9  * This library is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU Lesser General Public License as published by
11  * the Free Software Foundation; either version 2.1 of the License, or
12  * (at your option) any later version.
13  *
14  * This library is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17  * License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with this library; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
22  * USA.
23  *
24  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
25  * in the United States and other countries.]
26  *
27  * ---------------
28  * ExpressionInSelect.java
29  * ---------------
30  * Author: Volker Berlin
31  *
32  * Created on 07.08.2004
33  */
34 package smallsql.database;
35
36
37
38 /**
39  * @author Volker Berlin
40  */
41 class ExpressionInSelect extends ExpressionArithmetic {
42
43     final private CommandSelect cmdSel;
44     final private Index index = new Index(true);
45     final private SSConnection con;
46     
47     
48     ExpressionInSelect(SSConnection con, Expression left, CommandSelect cmdSel, int operation) {
49         super(left, (Expressions)null, operation);
50         this.cmdSel = cmdSel;
51         this.con = con;
52     }
53
54     
55     private void loadInList() throws Exception JavaDoc{
56         if(cmdSel.compile(con)){
57             cmdSel.join.execute();
58             if(cmdSel.columnExpressions.size() != 1)
59                 throw Utils.createSQLException("Count of columns in subquery must be 1 and not "+cmdSel.columnExpressions.size());
60             index.clear();
61             while(cmdSel.next()){
62                 try{
63                     index.addValues(0, cmdSel.columnExpressions );
64                 }catch(Exception JavaDoc e){
65                     //double values can not add
66 }
67             }
68         }
69     }
70     
71     boolean isInList() throws Exception JavaDoc{
72         loadInList();
73         return index.findRows( getParams(), null ) != null;
74     }
75 }
76
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