1 package org.apache.torque.adapter;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.sql.Connection;
23 import java.sql.SQLException;
24 import java.sql.Statement;
25
26 import org.apache.commons.logging.Log;
27 import org.apache.commons.logging.LogFactory;
28 import org.apache.torque.sql.Query;
29
30 /**
31 * This is used in order to connect to a MySQL database using the MM
32 * drivers. Simply comment the above and uncomment this code below and
33 * fill in the appropriate values for DB_NAME, DB_HOST, DB_USER,
34 * DB_PASS.
35 *
36 * <P><a href="http://www.mysql.com/">http://www.mysql.com/</a>
37 * <p>"jdbc:mysql://" + DB_HOST + "/" + DB_NAME + "?user=" +
38 * DB_USER + "&password=" + DB_PASS;
39 *
40 * @author <a href="mailto:jon@clearink.com">Jon S. Stevens</a>
41 * @author <a href="mailto:bmclaugh@algx.net">Brett McLaughlin</a>
42 * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
43 * @version $Id: MysqlAdapter.java 1355228 2012-06-29 03:38:08Z tfischer $
44 */
45 public class MysqlAdapter extends AbstractAdapter
46 {
47 /**
48 * Serial version
49 */
50 private static final long serialVersionUID = 7547291410802807010L;
51
52 /** The class log. */
53 private static Log log = LogFactory.getLog(DerbyAdapter.class);
54
55 /**
56 * Empty protected constructor.
57 */
58 protected MysqlAdapter()
59 {
60 // empty
61 }
62
63 /**
64 * This method is used to ignore case.
65 *
66 * @param in The string to transform to upper case.
67 * @return The upper case string.
68 */
69 @Override
70 public String toUpperCase(String in)
71 {
72 return in;
73 }
74
75 /**
76 * This method is used to ignore case.
77 *
78 * @param in The string whose case to ignore.
79 * @return The string in a case that can be ignored.
80 */
81 @Override
82 public String ignoreCase(String in)
83 {
84 return in;
85 }
86
87 /**
88 * @see org.apache.torque.adapter.Adapter#getIDMethodType()
89 */
90 @Override
91 public IDMethod getIDMethodType()
92 {
93 return IDMethod.AUTO_INCREMENT;
94 }
95
96 /**
97 * Returns the SQL to get the database key of the last row
98 * inserted, which in this case is <code>SELECT
99 * LAST_INSERT_ID()</code>.
100 *
101 * @see org.apache.torque.adapter.Adapter#getIDMethodSQL(Object obj)
102 */
103 @Override
104 public String getIDMethodSQL(Object obj)
105 {
106 return "SELECT LAST_INSERT_ID()";
107 }
108
109 /**
110 * Locks the specified table.
111 *
112 * @param con The JDBC connection to use.
113 * @param table The name of the table to lock.
114 * @exception SQLException No Statement could be created or
115 * executed.
116 */
117 @Override
118 public void lockTable(Connection con, String table) throws SQLException
119 {
120 Statement statement = null;
121 try
122 {
123 statement = con.createStatement();
124 StringBuffer stmt = new StringBuffer();
125 stmt.append("LOCK TABLE ").append(table).append(" WRITE");
126 statement.executeUpdate(stmt.toString());
127 statement.close();
128 statement = null;
129 }
130 finally
131 {
132 if (statement != null)
133 {
134 try
135 {
136 statement.close();
137 }
138 catch (SQLException e)
139 {
140 log.warn("Could not close statement", e);
141 }
142 }
143 }
144 }
145
146 /**
147 * Unlocks the specified table.
148 *
149 * @param con The JDBC connection to use.
150 * @param table The name of the table to unlock.
151 * @exception SQLException No Statement could be created or
152 * executed.
153 */
154 @Override
155 public void unlockTable(Connection con, String table) throws SQLException
156 {
157 Statement statement = null;
158 try
159 {
160 statement = con.createStatement();
161 statement.executeUpdate("UNLOCK TABLES");
162 statement.close();
163 statement = null;
164 }
165 finally
166 {
167 if (statement != null)
168 {
169 try
170 {
171 statement.close();
172 }
173 catch (SQLException e)
174 {
175 log.warn("Could not close statement", e);
176 }
177 }
178 }
179 }
180
181 /**
182 * Generate a LIMIT offset, limit clause if offset > 0
183 * or an LIMIT limit clause if limit is > 0 and offset
184 * is 0.
185 *
186 * @param query The query to modify
187 * @param offset the offset Value
188 * @param limit the limit Value
189 */
190 @Override
191 public void generateLimits(Query query, long offset, int limit)
192 {
193 if (offset > 0)
194 {
195 if (limit >= 0)
196 {
197 query.setLimit(Integer.toString(limit));
198 }
199 else
200 {
201 // Limit must always be set in mysql if offset is set
202 query.setLimit("18446744073709551615");
203 }
204 query.setOffset(Long.toString(offset));
205 }
206 else
207 {
208 if (limit >= 0)
209 {
210 query.setLimit(Integer.toString(limit));
211 }
212 }
213
214 query.setPreLimit(null);
215 query.setPostLimit(null);
216 }
217
218 /**
219 * Return true for MySQL
220 * @see org.apache.torque.adapter.AbstractAdapter#supportsNativeLimit()
221 */
222 @Override
223 public boolean supportsNativeLimit()
224 {
225 return true;
226 }
227
228 /**
229 * Return true for MySQL
230 * @see org.apache.torque.adapter.AbstractAdapter#supportsNativeOffset()
231 */
232 @Override
233 public boolean supportsNativeOffset()
234 {
235 return true;
236 }
237 }