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Java > Open Source Codes > oracle > toplink > essentials > internal > parsing > CountNode


1 /*
2  * The contents of this file are subject to the terms
3  * of the Common Development and Distribution License
4  * (the "License"). You may not use this file except
5  * in compliance with the License.
6  *
7  * You can obtain a copy of the license at
8  * glassfish/bootstrap/legal/CDDLv1.0.txt or
9  * https://glassfish.dev.java.net/public/CDDLv1.0.html.
10  * See the License for the specific language governing
11  * permissions and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL
14  * HEADER in each file and include the License file at
15  * glassfish/bootstrap/legal/CDDLv1.0.txt. If applicable,
16  * add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your
18  * own identifying information: Portions Copyright [yyyy]
19  * [name of copyright owner]
20  */
21 // Copyright (c) 1998, 2006, Oracle. All rights reserved.
22 package oracle.toplink.essentials.internal.parsing;
23
24 import oracle.toplink.essentials.queryframework.ObjectLevelReadQuery;
25 import oracle.toplink.essentials.queryframework.ReportQuery;
26 import oracle.toplink.essentials.expressions.Expression;
27
28 /**
29  * INTERNAL
30  * <p><b>Purpose</b>: Model a COUNT
31  * <p><b>Responsibilities</b>:<ul>
32  * <li> Apply itself to a query correctly
33  * </ul>
34  * @author Jon Driscoll
35  * @since TopLink 5.0
36  */
37 public class CountNode extends AggregateNode {
38
39     /**
40      * INTERNAL
41      * Apply this node to the passed query
42      */
43     public void applyToQuery(ObjectLevelReadQuery theQuery, GenerationContext context) {
44         if (theQuery.isReportQuery()) {
45             ReportQuery reportQuery = (ReportQuery)theQuery;
46             if (getLeft().isDotNode()) {
47                 //BUG 3240484: ReportQueries and COUNT will be handled by the normalization
48 //process in the expression framework
49 reportQuery.addCount(resolveAttribute(),
50                                      getArgumentExpression(context), Long JavaDoc.class);
51             } else {
52                 reportQuery.addCount("COUNT", getArgumentExpression(context), Long JavaDoc.class);
53             }
54         }
55     }
56
57     /**
58      * INTERNAL
59      * Validate node and calculate its type.
60      */
61     public void validate(ParseTreeContext context) {
62         if (left != null) {
63             left.validate(context);
64             TypeHelper typeHelper = context.getTypeHelper();
65             setType(typeHelper.getLongClassType());
66         }
67     }
68
69     /**
70      * INTERNAL
71      * Return a TopLink expression generated using the left node
72      */
73     public Expression generateExpression(GenerationContext context) {
74         return getArgumentExpression(context).count();
75     }
76
77     /**
78      * INTERNAL
79      * Is this node a CountNode
80      */
81     public boolean isCountNode() {
82         return true;
83     }
84     /**
85      * INTERNAL
86      * Get the string representation of this node.
87      */
88     public String JavaDoc getAsString() {
89         return "COUNT(" + left.getAsString() + ")";
90     }
91 }
92
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