01: /*
02: * $Id: DropViewCommand.java,v 1.5 2005/12/20 18:32:28 ahimanikya Exp $
03: * =======================================================================
04: * Copyright (c) 2002-2006 Axion Development Team. All rights reserved.
05: *
06: * Redistribution and use in source and binary forms, with or without
07: * modification, are permitted provided that the following conditions
08: * are met:
09: *
10: * 1. Redistributions of source code must retain the above
11: * copyright notice, this list of conditions and the following
12: * disclaimer.
13: *
14: * 2. Redistributions in binary form must reproduce the above copyright
15: * notice, this list of conditions and the following disclaimer in
16: * the documentation and/or other materials provided with the
17: * distribution.
18: *
19: * 3. The names "Tigris", "Axion", nor the names of its contributors may
20: * not be used to endorse or promote products derived from this
21: * software without specific prior written permission.
22: *
23: * 4. Products derived from this software may not be called "Axion", nor
24: * may "Tigris" or "Axion" appear in their names without specific prior
25: * written permission.
26: *
27: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
30: * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38: * =======================================================================
39: */
40:
41: package org.axiondb.engine.commands;
42:
43: import java.util.List;
44:
45: import org.axiondb.AxionException;
46: import org.axiondb.Database;
47: import org.axiondb.Table;
48:
49: /**
50: * A <code>DROP VIEW</code> command.
51: * @version $Revision: 1.5 $ $Date: 2005/12/20 18:32:28 $
52: * @author Ahimanikya Satapathy
53: */
54: public class DropViewCommand extends DropCommand {
55:
56: public DropViewCommand(String tableName, boolean exists,
57: boolean cascade) {
58: setObjectName(tableName);
59: setIfExists(exists);
60: setCascade(cascade);
61: }
62:
63: public boolean execute(Database db) throws AxionException {
64: assertNotReadOnly(db);
65: if (!isIfExists() || db.hasTable(getObjectName())) {
66: Table t = db.getTable(getObjectName());
67: if (t != null && t.getType().equals("VIEW")) {
68: dropDepedentViews(db);
69: db.dropTable(getObjectName());
70: } else {
71: throw new AxionException("No view " + getObjectName()
72: + " found");
73: }
74: }
75: return false;
76: }
77:
78: private void dropDepedentViews(Database db) throws AxionException {
79: List depedentViews = db.getDependentViews(getObjectName());
80: if (depedentViews.size() > 0) {
81: if (isCascade()) {
82: db.dropDependentViews(depedentViews);
83: } else {
84: throw new AxionException("Can't drop view: "
85: + getObjectName()
86: + " has reference in another View...");
87: }
88: }
89: }
90: }
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