01: package com.quadcap.sql;
02:
03: /* Copyright 1999 - 2003 Quadcap Software. All rights reserved.
04: *
05: * This software is distributed under the Quadcap Free Software License.
06: * This software may be used or modified for any purpose, personal or
07: * commercial. Open Source redistributions are permitted. Commercial
08: * redistribution of larger works derived from, or works which bundle
09: * this software requires a "Commercial Redistribution License"; see
10: * http://www.quadcap.com/purchase.
11: *
12: * Redistributions qualify as "Open Source" under one of the following terms:
13: *
14: * Redistributions are made at no charge beyond the reasonable cost of
15: * materials and delivery.
16: *
17: * Redistributions are accompanied by a copy of the Source Code or by an
18: * irrevocable offer to provide a copy of the Source Code for up to three
19: * years at the cost of materials and delivery. Such redistributions
20: * must allow further use, modification, and redistribution of the Source
21: * Code under substantially the same terms as this license.
22: *
23: * Redistributions of source code must retain the copyright notices as they
24: * appear in each source code file, these license terms, and the
25: * disclaimer/limitation of liability set forth as paragraph 6 below.
26: *
27: * Redistributions in binary form must reproduce this Copyright Notice,
28: * these license terms, and the disclaimer/limitation of liability set
29: * forth as paragraph 6 below, in the documentation and/or other materials
30: * provided with the distribution.
31: *
32: * The Software is provided on an "AS IS" basis. No warranty is
33: * provided that the Software is free of defects, or fit for a
34: * particular purpose.
35: *
36: * Limitation of Liability. Quadcap Software shall not be liable
37: * for any damages suffered by the Licensee or any third party resulting
38: * from use of the Software.
39: */
40:
41: import java.io.IOException;
42:
43: import java.sql.SQLException;
44:
45: import com.quadcap.sql.types.Value;
46: import com.quadcap.sql.types.ValueDefault;
47:
48: import com.quadcap.util.Debug;
49:
50: /**
51: * One part of a compiled <b>UPDATE</b> statement, including a column name and
52: * an expression which generates a value.
53: *
54: * @author Stan Bailes
55: */
56: public class UpdateItem {
57: String name;
58: Expression e;
59: Value v;
60: int col = -1;
61:
62: public UpdateItem(String name, Expression e) {
63: this .name = name;
64: this .e = e;
65: }
66:
67: void evaluate(Session session, Relation r, Cursor cursor)
68: throws SQLException, IOException {
69: if (col < 0) {
70: Column c = cursor.getColumn(name);
71: if (c == null) {
72: throw new SQLException("Bad column: " + name, "42000");
73: }
74: col = c.getColumn();
75: }
76: v = e.getValue(session, cursor);
77: if (v instanceof ValueDefault) {
78: Column c = r.getColumn(col);
79: Expression ex = c.getDefault();
80: if (ex != null) {
81: v = ex.getValue(session, cursor);
82: }
83: }
84: }
85:
86: public void update(Session session, Row row) throws SQLException,
87: IOException {
88: row.set(col, v);
89: }
90: }
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