Join


1   /******************************************************************************
2    * The contents of this file are subject to the   Compiere License  Version 1.1
3    * ("License"); You may not use this file except in compliance with the License
4    * You may obtain a copy of the License at http://www.compiere.org/license.html
5    * Software distributed under the License is distributed on an  "AS IS"  basis,
6    * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
7    * the specific language governing rights and limitations under the License.
8    * The Original Code is                  Compiere  ERP & CRM  Business Solution
9    * The Initial Developer of the Original Code is Jorg Janke  and ComPiere, Inc.
10   * Portions created by Jorg Janke are Copyright (C) 1999-2001 Jorg Janke, parts
11   * created by ComPiere are Copyright (C) ComPiere, Inc.;   All Rights Reserved.
12   * Contributor(s): ______________________________________.
13   *****************************************************************************/
14  package org.compiere.dbPort;
15  
16  import org.compiere.util.*;
17  
18  /**
19   *  Join Clause.
20   *  <pre>
21   *  f.AD_Column_ID = c.AD_Column_ID(+)
22   *  </pre>
23   *  @author     Jorg Janke
24   *  @version    $Id: Join.java,v 1.4 2002/08/12 01:55:15 danb Exp $
25   */
26  public class Join
27  {
28      /**
29       *  Constructor
30       *  @param joinClause
31       */
32      public Join (String   joinClause)
33      {
34          if (joinClause == null)
35              throw new IllegalArgumentException  ("Join - clause cannot be null");
36          evaluate (joinClause);
37      }   //  Join
38  
39      private String    m_joinClause;
40      private String    m_mainTable;
41      private String    m_mainAlias;
42      private String    m_joinTable;
43      private String    m_joinAlias;
44      private boolean m_left;
45      private String    m_condition;
46  
47      /**
48       *  Evaluate the clause.
49       *  e.g.    tb.AD_User_ID(+)=?
50       *          f.AD_Column_ID = c.AD_Column_ID(+)
51       *  @param joinClause
52       */
53      private void evaluate (String   joinClause)
54      {
55          m_joinClause = joinClause;
56          int indexEqual = joinClause.indexOf('=');
57          m_left = indexEqual < joinClause.indexOf("(+)");    //  converts to LEFT if true
58          //  get table alias of it
59          if (m_left)     //  f.AD_Column_ID = c.AD_Column_ID(+)  => f / c
60          {
61              m_mainAlias = joinClause.substring
62                  (0, Util.findIndexOf(joinClause, '.','=')).trim();          //  f
63              int end = joinClause.indexOf('.', indexEqual);
64              if (end == -1)  //  no alias
65                  end = joinClause.indexOf('(', indexEqual);
66              m_joinAlias  = joinClause.substring(indexEqual+1, end).trim();  //  c
67          }
68          else            //  f.AD_Column_ID(+) = c.AD_Column_ID  => c / f
69          {
70              int end = joinClause.indexOf('.', indexEqual);
71              if (end == -1)  //  no alias
72                  end = joinClause.length();
73              m_mainAlias  = joinClause.substring(indexEqual+1, end).trim();  //  c
74              m_joinAlias = joinClause.substring
75                  (0, Util.findIndexOf(joinClause, '.','(')).trim();          //  f
76          }
77          m_condition = Util.replace(joinClause, "(+)", "").trim();
78      }   //  evaluate
79  
80      /**
81       *  Get origial Join Clause.
82       *  e.g. f.AD_Column_ID = c.AD_Column_ID(+)
83       *  @return Join cluase
84       */
85      public String   getJoinClause()
86      {
87          return m_joinClause;
88      }   //  getJoinClause
89  
90      /**
91       *  Get Main Table Alias
92       *  @return Main Table Alias
93       */
94      public String   getMainAlias()
95      {
96          return m_mainAlias;
97      }   //  getMainAlias
98  
99      /**
100      *  Get Join Table Alias
101      *  @return Join Table Alias
102      */
103     public String   getJoinAlias()
104     {
105         return m_joinAlias;
106     }   //  getJoinAlias
107 
108     /**
109      *  Is Left Aouter Join
110      *  @return true if left outer join
111      */
112     public boolean isLeft()
113     {
114         return m_left;
115     }   //  isLeft
116 
117     /**
118      *  Get Join condition.
119      *  e.g. f.AD_Column_ID = c.AD_Column_ID
120      *  @return join condition
121      */
122     public String   getCondition()
123     {
124         return m_condition;
125     }   //  getCondition
126 
127     /*************************************************************************/
128 
129     /**
130      *  Set Main Table Name.
131      *  If table name equals alias, the alias is set to ""
132      *  @param mainTable
133      */
134     public void setMainTable(String   mainTable)
135     {
136         if (mainTable == null || mainTable.length() == 0)
137             return;
138         m_mainTable = mainTable;
139         if (m_mainAlias.equals(mainTable))
140             m_mainAlias = "";
141     }   //  setMainTable
142 
143     /**
144      *  Get Main Table Name
145      *  @return Main Table Name
146      */
147     public String   getMainTable()
148     {
149         return m_mainTable;
150     }   //  getMainTable
151 
152     /**
153      *  Set Main Table Name.
154      *  If table name equals alias, the alias is set to ""
155      *  @param joinTable
156      */
157     public void setJoinTable(String   joinTable)
158     {
159         if (joinTable == null || joinTable.length() == 0)
160             return;
161         m_joinTable = joinTable;
162         if (m_joinAlias.equals(joinTable))
163             m_joinAlias = "";
164     }   //  setJoinTable
165 
166     /**
167      *  Get Join Table Name
168      *  @return Join Table Name
169      */
170     public String   getJoinTable()
171     {
172         return m_joinTable;
173     }   //  getJoinTable
174 
175     /*************************************************************************/
176 
177     /**
178      *  This Join is a condition of the first Join.
179      *  e.g. tb.AD_User_ID(+)=?  or tb.AD_User_ID(+)='123'
180      *  @param first
181      *  @return true if condition
182      */
183     public boolean isConditionOf (Join first)
184     {
185         if (m_mainTable == null         //  did not find Table from "Alias"
186             && (first.getJoinTable().equals(m_joinTable)        //  same join table
187                 || first.getMainAlias().equals(m_joinTable)))   //  same main table
188             return true;
189         return false;
190     }   //  isConditionOf
191 
192     /**
193      *  String representation
194      *  @return info
195      */
196     public String   toString()
197     {
198         StringBuffer   sb = new StringBuffer   ("Join[");
199         sb.append(m_joinClause)
200             .append(" - Main=").append(m_mainTable).append("/").append(m_mainAlias)
201             .append(", Join=").append(m_joinTable).append("/").append(m_joinAlias)
202             .append(", Left=").append(m_left)
203             .append(", Condition=").append(m_condition)
204             .append("]");
205         return sb.toString();
206     }   //  toString
207 
208 }   //  Join
209
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