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: *
23: * Free Software Foundation, Inc.
24: * 59 Temple Place, Suite 330
25: * Boston, MA 02111-1307 USA
26: *
27: * @author Scott Ferguson
28: */
29:
30: package com.caucho.db.sql;
31:
32: import com.caucho.db.Database;
33: import com.caucho.db.store.Transaction;
34: import com.caucho.db.table.Table;
35: import com.caucho.db.table.TableIterator;
36: import com.caucho.log.Log;
37: import com.caucho.util.CharBuffer;
38:
39: import java.sql.SQLException;
40: import java.util.logging.Logger;
41:
42: class DeleteQuery extends Query {
43: private static final Logger log = Log.open(DeleteQuery.class);
44:
45: private final Table _table;
46:
47: DeleteQuery(Database db, String sql, Table table)
48: throws SQLException {
49: super (db, sql, null);
50:
51: _table = table;
52:
53: setFromItems(new FromItem[] { new FromItem(table, table
54: .getName()) });
55: }
56:
57: public boolean isReadOnly() {
58: return false;
59: }
60:
61: /**
62: * Executes the query.
63: */
64: public void execute(QueryContext context, Transaction xa)
65: throws SQLException {
66: int count = 0;
67: TableIterator[] rows = new TableIterator[1];
68: rows[0] = _table.createTableIterator();
69: context.init(xa, rows, isReadOnly());
70:
71: try {
72: if (!start(rows, rows.length, context, xa))
73: return;
74:
75: do {
76: rows[0].delete();
77:
78: context.setRowUpdateCount(++count);
79: } while (nextTuple(rows, rows.length, context, xa));
80: } finally {
81: // autoCommitWrite must be before freeRows in case freeRows
82: // throws an exception
83: context.unlock();
84:
85: freeRows(rows, rows.length);
86: }
87: }
88:
89: public String toString() {
90: CharBuffer cb = new CharBuffer();
91: cb.append("DeleteQuery[");
92: if (_whereExpr != null) {
93: cb.append(",where:" + _whereExpr);
94: }
95: cb.append("]");
96:
97: return cb.close();
98: }
99: }
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