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Java > Open Source Codes > com > caucho > amber > expr > fun > SizeFunExpr


1 /*
2  * Copyright (c) 1998-2006 Caucho Technology -- all rights reserved
3  *
4  * This file is part of Resin(R) Open Source
5  *
6  * Each copy or derived work must preserve the copyright notice and this
7  * notice unmodified.
8  *
9  * Resin Open Source is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * Resin Open Source is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17  * of NON-INFRINGEMENT. See the GNU General Public License for more
18  * details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with Resin Open Source; if not, write to the
22  * Free Software Foundation, Inc.
23  * 59 Temple Place, Suite 330
24  * Boston, MA 02111-1307 USA
25  *
26  * @author Scott Ferguson
27  */
28
29 package com.caucho.amber.expr.fun;
30
31 import com.caucho.amber.expr.*;
32 import com.caucho.amber.query.*;
33 import com.caucho.amber.table.*;
34 import com.caucho.util.CharBuffer;
35 import com.caucho.util.L10N;
36
37 import java.util.ArrayList JavaDoc;
38
39
40 /**
41  * SIZE function expression
42  */
43 public class SizeFunExpr extends FunExpr {
44   private static final L10N L = new L10N(SizeFunExpr.class);
45
46   /**
47    * Creates a new expression
48    */
49   protected SizeFunExpr(QueryParser parser,
50                         ArrayList JavaDoc<AmberExpr> args)
51   {
52     super(parser, "size", args, false);
53   }
54
55   public static FunExpr create(QueryParser parser,
56                                ArrayList JavaDoc<AmberExpr> args)
57   {
58     return new SizeFunExpr(parser, args);
59   }
60
61   /**
62    * Generates the where expression.
63    */
64   public void generateWhere(CharBuffer cb)
65   {
66     generateInternalWhere(cb, true);
67   }
68
69   /**
70    * Generates the (update) where expression.
71    */
72   public void generateUpdateWhere(CharBuffer cb)
73   {
74     generateInternalWhere(cb, false);
75   }
76
77   /**
78    * Generates the where clause.
79    */
80   void generateInternalWhere(CharBuffer cb,
81                              boolean select)
82   {
83     cb.append("count(");
84
85     AmberExpr arg = _args.get(0);
86
87     if (arg instanceof OneToManyExpr) {
88
89       // jpa/119m
90
91       OneToManyExpr oneToMany = (OneToManyExpr) arg;
92
93       FromItem fromItem = oneToMany.getChildFromItem();
94
95       cb.append(fromItem.getName());
96       cb.append('.');
97
98       LinkColumns linkColumns = oneToMany.getLinkColumns();
99       ForeignColumn fkColumn = linkColumns.getColumns().get(0);
100
101       cb.append(fkColumn.getName());
102     }
103     else {
104       if (select)
105         arg.generateWhere(cb);
106       else
107         arg.generateUpdateWhere(cb);
108     }
109
110     cb.append(')');
111   }
112 }
113
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