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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  import org.jumpmind.symmetric.model.TriggerHistory;
34  
35  public class MySqlDbDialect extends AbstractDbDialect implements IDbDialect {
36  
37      static final Log logger = LogFactory.getLog(MySqlDbDialect.class);
38  
39      static final String TRANSACTION_ID_FUNCTION_NAME = "fn_transaction_id";
40  
41      static final String SYNC_TRIGGERS_DISABLED_USER_VARIABLE = "@sync_triggers_disabled";
42      
43      static final String SYNC_TRIGGERS_DISABLED_NODE_VARIABLE = "@sync_node_disabled";
44  
45      private boolean supportsTransactionId = false;
46  
47      protected void initForSpecificDialect() {
48          int[] versions = Version.parseVersion(getProductVersion());
49          if (getMajorVersion() == 5
50                  && (getMinorVersion() == 0 || (getMinorVersion() == 1 && versions[2] < 23))) {
51              logger.info("Enabling transaction ID support");
52              supportsTransactionId = true;
53          }
54      }
55  
56      @Override
57      protected void createRequiredFunctions() {
58          String[] functions = sqlTemplate.getFunctionsToInstall();
59          for (String funcName : functions) {
60              if (! funcName.equals("fn_transaction_id") || supportsTransactionId) {
61                  if (jdbcTemplate.queryForInt(sqlTemplate.getFunctionInstalledSql(funcName)) == 0) {
62                      jdbcTemplate.update(sqlTemplate.getFunctionSql(funcName));
63                      logger.info("Just installed " + funcName);
64                  }
65              }
66          }
67      }
68  
69      @Override
70      protected boolean doesTriggerExistOnPlatform(String catalog, String schema, String tableName, String triggerName) {
71          catalog = catalog == null ? (getDefaultCatalog() == null ? null : getDefaultCatalog()) : catalog;
72          String checkCatalogSql = (catalog != null && catalog.length() > 0) ? " and trigger_schema='" + catalog + "'"
73                  : "";
74          return jdbcTemplate.queryForInt(
75                  "select count(*) from information_schema.triggers where trigger_name like ? and event_object_table like ?"
76                          + checkCatalogSql, new Object[] { triggerName, tableName }) > 0;
77      }
78  
79      // TODO this belongs in SqlTemplate
80      public void removeTrigger(String catalogName, String schemaName, String triggerName, String tableName, TriggerHistory oldHistory) {
81          catalogName = catalogName == null ? "" : (catalogName + ".");
82          try {
83              jdbcTemplate.update("drop trigger " + catalogName + triggerName);
84          } catch (Exception e) {
85              logger.warn("Trigger does not exist");
86          }
87      }
88  
89      public void disableSyncTriggers(String nodeId) {
90          jdbcTemplate.update("set " + SYNC_TRIGGERS_DISABLED_USER_VARIABLE + "=1");
91          if (nodeId != null) {
92              jdbcTemplate.update("set " + SYNC_TRIGGERS_DISABLED_NODE_VARIABLE + "='" + nodeId + "'");
93          }
94      }
95  
96      public void enableSyncTriggers() {
97          jdbcTemplate.update("set " + SYNC_TRIGGERS_DISABLED_USER_VARIABLE + "=null");
98          jdbcTemplate.update("set " + SYNC_TRIGGERS_DISABLED_NODE_VARIABLE + "=null");
99      }
100 
101     public String getSyncTriggersExpression() {
102         return SYNC_TRIGGERS_DISABLED_USER_VARIABLE + " is null";
103     }
104 
105     // Mister CHenson, what is this non-sense?
106     public String getTransactionTriggerExpression(Trigger trigger) {
107         if (supportsTransactionId) {
108             String defaultCatalog = "";
109             if (trigger.getSourceCatalogName() != null) {
110                 defaultCatalog = this.getDefaultCatalog() + ".";
111             }
112             return defaultCatalog + TRANSACTION_ID_FUNCTION_NAME + "()";
113         }
114         return "null";
115     }
116 
117     public boolean supportsTransactionId() {
118         return supportsTransactionId;
119     }
120 
121     public String getSelectLastInsertIdSql(String sequenceName) {
122         return "select last_insert_id()";
123     }
124 
125     public boolean isCharSpacePadded() {
126         return false;
127     }
128 
129     public boolean isCharSpaceTrimmed() {
130         return true;
131     }
132 
133     public boolean isEmptyStringNulled() {
134         return false;
135     }
136 
137     public void purge() {
138     }
139 
140     public String getDefaultSchema() {
141         return null;
142     }
143 
144     public String getDefaultCatalog() {
145         return (String) jdbcTemplate.queryForObject("select database()", String.class);
146     }
147 
148     protected String switchCatalogForTriggerInstall(String catalog, Connection c) throws SQLException {
149         if (catalog != null) {
150             String previousCatalog = c.getCatalog();
151             c.setCatalog(catalog);
152             return previousCatalog;
153         } else {
154             return null;
155         }
156     }
157 
158     /***
159      * According to the documentation (and experience) the jdbc driver for mysql
160      * requires the fetch size to be as follows.
161      */
162     @Override
163     public int getStreamingResultsFetchSize() {
164         return Integer.MIN_VALUE;
165     }
166 
167     public BinaryEncoding getBinaryEncoding() {
168         return BinaryEncoding.HEX;
169     }
170     
171     public String getIdentifierQuoteString()
172     {
173         return "`";
174     }
175 
176 }