01: /*
02: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
03: *
04: * This file is part of Resin(R) Open Source
05: *
06: * Each copy or derived work must preserve the copyright notice and this
07: * notice unmodified.
08: *
09: * Resin Open Source is free software; you can redistribute it and/or modify
10: * it under the terms of the GNU General Public License as published by
11: * the Free Software Foundation; either version 2 of the License, or
12: * (at your option) any later version.
13: *
14: * Resin Open Source is distributed in the hope that it will be useful,
15: * but WITHOUT ANY WARRANTY; without even the implied warranty of
16: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17: * of NON-INFRINGEMENT. See the GNU General Public License for more
18: * details.
19: *
20: * You should have received a copy of the GNU General Public License
21: * along with Resin Open Source; if not, write to the
22: * Free SoftwareFoundation, Inc.
23: * 59 Temple Place, Suite 330
24: * Boston, MA 02111-1307 USA
25: *
26: * @author Scott Ferguson
27: */
28:
29: package com.caucho.db.sql;
30:
31: import com.caucho.log.Log;
32: import com.caucho.util.L10N;
33:
34: import java.sql.SQLException;
35: import java.util.ArrayList;
36: import java.util.logging.Logger;
37:
38: public class SubSelectEvalExpr extends Expr {
39: protected static final L10N L = new L10N(SubSelectEvalExpr.class);
40: private static final Logger log = Log.open(SubSelectEvalExpr.class);
41:
42: private SubSelectExpr _subselect;
43:
44: SubSelectEvalExpr(SubSelectExpr subselect) {
45: _subselect = subselect;
46: }
47:
48: /**
49: * Returns the expected result type of the expression.
50: */
51: public Class getType() {
52: return boolean.class;
53: }
54:
55: /**
56: * Returns the cost based on the given FromList.
57: */
58: public long subCost(ArrayList<FromItem> fromList) {
59: return _subselect.subCost(fromList);
60: }
61:
62: /**
63: * Evaluates the expression as a boolean.
64: *
65: * @param rows the current database tuple
66: *
67: * @return the string value
68: */
69: public int evalBoolean(QueryContext context) throws SQLException {
70: _subselect.evaluate(context);
71:
72: return TRUE;
73: }
74:
75: /**
76: * Evaluates the expression as a string.
77: *
78: * @param rows the current database tuple
79: *
80: * @return the string value
81: */
82: public String evalString(QueryContext context) throws SQLException {
83: throw new UnsupportedOperationException();
84: }
85:
86: public String toString() {
87: return "SubSelectEvalExpr[" + _subselect.getSubSelect() + "]";
88: }
89: }
|