001: package com.quadcap.sql;
002:
003: /* Copyright 1999 - 2003 Quadcap Software. All rights reserved.
004: *
005: * This software is distributed under the Quadcap Free Software License.
006: * This software may be used or modified for any purpose, personal or
007: * commercial. Open Source redistributions are permitted. Commercial
008: * redistribution of larger works derived from, or works which bundle
009: * this software requires a "Commercial Redistribution License"; see
010: * http://www.quadcap.com/purchase.
011: *
012: * Redistributions qualify as "Open Source" under one of the following terms:
013: *
014: * Redistributions are made at no charge beyond the reasonable cost of
015: * materials and delivery.
016: *
017: * Redistributions are accompanied by a copy of the Source Code or by an
018: * irrevocable offer to provide a copy of the Source Code for up to three
019: * years at the cost of materials and delivery. Such redistributions
020: * must allow further use, modification, and redistribution of the Source
021: * Code under substantially the same terms as this license.
022: *
023: * Redistributions of source code must retain the copyright notices as they
024: * appear in each source code file, these license terms, and the
025: * disclaimer/limitation of liability set forth as paragraph 6 below.
026: *
027: * Redistributions in binary form must reproduce this Copyright Notice,
028: * these license terms, and the disclaimer/limitation of liability set
029: * forth as paragraph 6 below, in the documentation and/or other materials
030: * provided with the distribution.
031: *
032: * The Software is provided on an "AS IS" basis. No warranty is
033: * provided that the Software is free of defects, or fit for a
034: * particular purpose.
035: *
036: * Limitation of Liability. Quadcap Software shall not be liable
037: * for any damages suffered by the Licensee or any third party resulting
038: * from use of the Software.
039: */
040:
041: import java.io.Externalizable;
042: import java.io.IOException;
043: import java.io.ObjectInput;
044: import java.io.ObjectOutput;
045: import java.io.OutputStream;
046:
047: import java.sql.SQLException;
048:
049: import com.quadcap.util.Debug;
050: import com.quadcap.sql.io.Extern;
051:
052: /**
053: * Log step to add a table to a database.
054: *
055: * @author Stan Bailes
056: */
057: public class AddTable extends LogStep implements Externalizable {
058: Relation table;
059:
060: /**
061: * Default constructor
062: */
063: public AddTable() {
064: }
065:
066: /**
067: * Explicit constructor from table
068: */
069: public AddTable(Session session, Relation table) {
070: super (session);
071: this .table = table;
072: }
073:
074: /**
075: * LogStep.redo(): Add the table to the database
076: */
077: public void redo(Session session) throws IOException, SQLException {
078: Database db = session.getDatabase();
079: db.addRelation(table);
080: }
081:
082: /**
083: * LogStep.undo(): Remove the table from the database
084: */
085: public void undo(Session session) throws IOException, SQLException {
086: Database db = session.getDatabase();
087: db.removeRelation(table.getName());
088: }
089:
090: /**
091: * LogStep.prepare(): We check for already-existing table and throw
092: * exception early, rather than let the user proceed under false
093: * illusions.
094: */
095: public void prepare(Session session) throws IOException,
096: SQLException {
097: Database db = session.getDatabase();
098: if (db.getRelation(table.getName()) != null) {
099: throw new SQLException("Table/view already exists: "
100: + table.getName(), "42000");
101: }
102: }
103:
104: /**
105: * Read me from a stream
106: */
107: public void readExternal(ObjectInput in) throws IOException,
108: ClassNotFoundException {
109: super .readExternal(in);
110: table = (Relation) in.readObject();
111: }
112:
113: /**
114: * Write me to a stream
115: */
116: public void writeExternal(ObjectOutput out) throws IOException {
117: super .writeExternal(out);
118: out.writeObject(table);
119: }
120:
121: //#ifdef DEBUG
122: /**
123: * Return a displayable representation for debugging
124: */
125: public String toString() {
126: StringBuffer sb = new StringBuffer(super .toString());
127: sb.append(" AddTable(");
128: sb.append(table.toString());
129: sb.append(')');
130: return sb.toString();
131: }
132:
133: //#endif
134:
135: static Extern extern;
136:
137: public void setExtern(Extern extern) {
138: AddTable.extern = extern;
139: }
140:
141: public Extern getExtern() {
142: return extern;
143: }
144: }
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