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1   /*
2    * SymmetricDS is an open source database synchronization solution.
3    *   
4    * Copyright (C) Chris Henson <chenson42@users.sourceforge.net>
5    *
6    * This library is free software; you can redistribute it and/or
7    * modify it under the terms of the GNU Lesser General Public
8    * License as published by the Free Software Foundation; either
9    * version 3 of the License, or (at your option) any later version.
10   *
11   * This library is distributed in the hope that it will be useful,
12   * but WITHOUT ANY WARRANTY; without even the implied warranty of
13   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14   * Lesser General Public License for more details.
15   *
16   * You should have received a copy of the GNU Lesser General Public
17   * License along with this library; if not, see
18   * <http://www.gnu.org/licenses/>.
19   */
20  
21  package org.jumpmind.symmetric.db.mysql;
22  
23  import java.sql.Connection;
24  import java.sql.SQLException;
25  
26  import org.apache.commons.logging.Log;
27  import org.apache.commons.logging.LogFactory;
28  import org.jumpmind.symmetric.Version;
29  import org.jumpmind.symmetric.db.AbstractDbDialect;
30  import org.jumpmind.symmetric.db.BinaryEncoding;
31  import org.jumpmind.symmetric.db.IDbDialect;
32  import org.jumpmind.symmetric.model.Trigger;
33  
34  public class MySqlDbDialect extends AbstractDbDialect implements IDbDialect {
35  
36      static final Log logger = LogFactory.getLog(MySqlDbDialect.class);
37  
38      static final String TRANSACTION_ID_FUNCTION_NAME = "fn_transaction_id";
39  
40      static final String SYNC_TRIGGERS_DISABLED_USER_VARIABLE = "@sync_triggers_disabled";
41  
42      private boolean supportsTransactionId = false;
43  
44      protected void initForSpecificDialect() {
45          int[] versions = Version.parseVersion(getProductVersion());
46          if (getMajorVersion() == 5
47                  && (getMinorVersion() == 0 || (getMinorVersion() == 1 && versions[2] < 23))) {
48              logger.info("Enabling transaction ID support");
49              supportsTransactionId = true;
50          }
51      }
52  
53      @Override
54      protected void createRequiredFunctions() {
55          String[] functions = sqlTemplate.getFunctionsToInstall();
56          for (String funcName : functions) {
57              if (! funcName.equals("fn_transaction_id") || supportsTransactionId) {
58                  if (jdbcTemplate.queryForInt(sqlTemplate.getFunctionInstalledSql(funcName)) == 0) {
59                      jdbcTemplate.update(sqlTemplate.getFunctionSql(funcName));
60                      logger.info("Just installed " + funcName);
61                  }
62              }
63          }
64      }
65  
66      @Override
67      protected boolean doesTriggerExistOnPlatform(String catalog, String schema, String tableName, String triggerName) {
68          catalog = catalog == null ? (getDefaultCatalog() == null ? null : getDefaultCatalog()) : catalog;
69          String checkCatalogSql = (catalog != null && catalog.length() > 0) ? " and trigger_schema='" + catalog + "'"
70                  : "";
71          return jdbcTemplate.queryForInt(
72                  "select count(*) from information_schema.triggers where trigger_name like ? and event_object_table like ?"
73                          + checkCatalogSql, new Object[] { triggerName, tableName }) > 0;
74      }
75  
76      // TODO this belongs in SqlTemplate
77      public void removeTrigger(String catalogName, String schemaName, String triggerName, String tableName) {
78          catalogName = catalogName == null ? "" : (catalogName + ".");
79          try {
80              jdbcTemplate.update("drop trigger " + catalogName + triggerName);
81          } catch (Exception e) {
82              logger.warn("Trigger does not exist");
83          }
84      }
85  
86      public void disableSyncTriggers() {
87          jdbcTemplate.update("set " + SYNC_TRIGGERS_DISABLED_USER_VARIABLE + "=1");
88      }
89  
90      public void enableSyncTriggers() {
91          jdbcTemplate.update("set " + SYNC_TRIGGERS_DISABLED_USER_VARIABLE + "=null");
92      }
93  
94      public String getSyncTriggersExpression() {
95          return SYNC_TRIGGERS_DISABLED_USER_VARIABLE + " is null";
96      }
97  
98      // Mister CHenson, what is this non-sense?
99      public String getTransactionTriggerExpression(Trigger trigger) {
100         if (supportsTransactionId) {
101             String defaultCatalog = "";
102             if (trigger.getSourceCatalogName() != null) {
103                 defaultCatalog = this.getDefaultCatalog() + ".";
104             }
105             return defaultCatalog + TRANSACTION_ID_FUNCTION_NAME + "()";
106         }
107         return "null";
108     }
109 
110     public boolean supportsTransactionId() {
111         return supportsTransactionId;
112     }
113 
114     public String getSelectLastInsertIdSql(String sequenceName) {
115         return "select last_insert_id()";
116     }
117 
118     public boolean isCharSpacePadded() {
119         return false;
120     }
121 
122     public boolean isCharSpaceTrimmed() {
123         return true;
124     }
125 
126     public boolean isEmptyStringNulled() {
127         return false;
128     }
129 
130     public void purge() {
131     }
132 
133     public String getDefaultSchema() {
134         return null;
135     }
136 
137     public String getDefaultCatalog() {
138         return (String) jdbcTemplate.queryForObject("select database()", String.class);
139     }
140 
141     protected String switchCatalogForTriggerInstall(String catalog, Connection c) throws SQLException {
142         if (catalog != null) {
143             String previousCatalog = c.getCatalog();
144             c.setCatalog(catalog);
145             return previousCatalog;
146         } else {
147             return null;
148         }
149     }
150 
151     /***
152      * According to the documentation (and experience) the jdbc driver for mysql
153      * requires the fetch size to be as follows.
154      */
155     @Override
156     public int getStreamingResultsFetchSize() {
157         return Integer.MIN_VALUE;
158     }
159 
160     public BinaryEncoding getBinaryEncoding() {
161         return BinaryEncoding.HEX;
162     }
163     
164     public String getIdentifierQuoteString()
165     {
166         return "";
167     }
168 
169 }