1   /**
2    * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3    *
4    * Permission is hereby granted, free of charge, to any person obtaining a copy
5    * of this software and associated documentation files (the "Software"), to deal
6    * in the Software without restriction, including without limitation the rights
7    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8    * copies of the Software, and to permit persons to whom the Software is
9    * furnished to do so, subject to the following conditions:
10   *
11   * The above copyright notice and this permission notice shall be included in
12   * all copies or substantial portions of the Software.
13   *
14   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20   * SOFTWARE.
21   */
22  
23  package com.liferay.portal.dao.orm.common;
24  
25  import com.liferay.portal.kernel.log.Log;
26  import com.liferay.portal.kernel.log.LogFactoryUtil;
27  import com.liferay.portal.kernel.util.StringPool;
28  import com.liferay.portal.tools.sql.DBUtil;
29  import com.liferay.portal.util.PropsValues;
30  
31  import java.util.HashMap;
32  import java.util.Map;
33  
34  /**
35   * <a href="SQLTransformer.java.html"><b><i>View Source</i></b></a>
36   *
37   * @author Brian Wing Shun Chan
38   *
39   */
40  public class SQLTransformer {
41  
42      public static String transform(String sql) {
43          return _instance._transform(sql);
44      }
45  
46      private SQLTransformer() {
47          _sqlMap = new HashMap<String, String>();
48  
49          DBUtil dbUtil = DBUtil.getInstance();
50  
51          if (dbUtil.getType().equals(DBUtil.TYPE_MYSQL)) {
52              _vendorMySQL = true;
53          }
54      }
55  
56      private String _removeLower(String sql) {
57          int x = sql.indexOf(_LOWER_OPEN);
58  
59          if (x == -1) {
60              return sql;
61          }
62  
63          String newSQL = _sqlMap.get(sql);
64  
65          if (newSQL != null) {
66              return newSQL;
67          }
68  
69          StringBuilder sb = new StringBuilder(sql.length());
70  
71          int y = 0;
72  
73          while (true) {
74              sb.append(sql.substring(y, x));
75  
76              y = sql.indexOf(_LOWER_CLOSE, x);
77  
78              if (y == -1) {
79                  sb.append(sql.substring(x));
80  
81                  break;
82              }
83  
84              sb.append(sql.substring(x + _LOWER_OPEN.length(), y));
85  
86              y++;
87  
88              x = sql.indexOf(_LOWER_OPEN, y);
89  
90              if (x == -1) {
91                  sb.append(sql.substring(y));
92  
93                  break;
94              }
95          }
96  
97          newSQL = sb.toString();
98  
99          if (_log.isDebugEnabled()) {
100             _log.debug("Original SQL " + sql);
101             _log.debug("Modified SQL " + newSQL);
102         }
103 
104         _sqlMap.put(sql, newSQL);
105 
106         return newSQL;
107     }
108 
109     private String _transform(String sql) {
110         if (sql == null) {
111             return sql;
112         }
113 
114         if (_vendorMySQL &&
115             !PropsValues.DATABASE_MYSQL_FUNCTION_LOWER_ENABLED) {
116 
117             sql = _removeLower(sql);
118         }
119 
120         return sql;
121     }
122 
123     private static final String _LOWER_CLOSE = StringPool.CLOSE_PARENTHESIS;
124 
125     private static final String _LOWER_OPEN = "lower(";
126 
127     private static Log _log = LogFactoryUtil.getLog(SQLTransformer.class);
128 
129     private static SQLTransformer _instance = new SQLTransformer();
130 
131     private Map<String, String> _sqlMap;
132     private boolean _vendorMySQL;
133 
134 }