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Java > Open Source Codes > com > sun > jdo > api > persistence > model > mapping > MappingTableElement


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 in
5  * compliance with the License.
6  *
7  * You can obtain a copy of the license at
8  * https://glassfish.dev.java.net/public/CDDLv1.0.html or
9  * glassfish/bootstrap/legal/CDDLv1.0.txt.
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 Notice in each file and include the License file
15  * at glassfish/bootstrap/legal/CDDLv1.0.txt.
16  * If applicable, add the following below the CDDL Header,
17  * with the fields enclosed by brackets [] replaced by
18  * you own identifying information:
19  * "Portions Copyrighted [year] [name of copyright owner]"
20  *
21  * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
22  */
23
24 /*
25  * MappingTableElement.java
26  *
27  * Created on March 3, 2000, 1:11 PM
28  */
29
30 package com.sun.jdo.api.persistence.model.mapping;
31
32 import java.util.ArrayList JavaDoc;
33
34 import org.netbeans.modules.dbschema.TableElement;
35 import org.netbeans.modules.dbschema.ColumnElement;
36
37 import com.sun.jdo.api.persistence.model.ModelException;
38
39 /**
40  * This is an element which represents a database table. It exists (separately
41  * from TableElement in the database model) to allow the runtime to use a
42  * description of the underlying table that differs from the actual database.
43  * For example, mapping table contains a key which can be thought of as a
44  * "fake primary key" and designates the columns which the runtime will use
45  * to identify rows. It is analagous to the primary key of the underlying
46  * database table and is typically the same, however the important point
47  * is that it is not a requirement. The table in the database may have a
48  * different primary key or may have no primary key at all. Similarly, the
49  * mapping table contains a list of reference keys which can be thought of as
50  * "fake foreign key" objects and designate the column pairs used to join
51  * the primary table with a secondary table. These are analagous to
52  * foreign keys and may in fact contain identical pairs as the foreign key,
53  * but again, this is not a requirement. The foreign key may define a
54  * different set of pairs or may not exist at all. Although any set of pairs
55  * is legal, the user should be careful to define pairs which represent a
56  * logical relationship between the two tables.
57  * Any mapping table elements which are designated as primary tables have
58  * their key set up automatically. Any mapping table elements which are
59  * designated as secondary tables should not have their keys set up directly;
60  * the setup is automatically part of the pair definition which makes up the
61  * reference key.
62  *
63  * @author Mark Munro
64  * @author Rochelle Raccah
65  * @version %I%
66  */
67 public interface MappingTableElement extends MappingMemberElement
68 {
69     //======================= table handling ===========================
70
71     /** Returns the name of the table element used by this mapping table.
72      * @return the table name for this mapping table
73      */
74     public String JavaDoc getTable ();
75
76     /** Set the table element for this mapping table to the supplied table.
77      * @param table table element to be used by the mapping table.
78      * @exception ModelException if impossible
79      */
80     public void setTable (TableElement table) throws ModelException;
81
82     /** Returns true if the table element used by this mapping table is equal
83      * to the supplied table.
84      * @return <code>true</code> if table elements are equal,
85      * <code>false</code> otherwise.
86      */
87     public boolean isEqual (TableElement table);
88
89     //===================== primary key handling ===========================
90
91     /** Returns the list of column names in the primary key for this
92      * mapping table.
93      * @return the names of the columns in the primary key for this
94      * mapping table
95      */
96     public ArrayList JavaDoc getKey ();
97
98     /** Adds a column to the primary key of columns in this mapping table.
99      * This method should only be used to manipulate the key columns of the
100      * primary table. The secondary table key columns should be manipulated
101      * using MappingReferenceKeyElement methods for pairs.
102      * @param column column element to be added
103      * @exception ModelException if impossible
104      */
105     public void addKeyColumn (ColumnElement column) throws ModelException;
106
107     /** Removes a column from the primary key of columns in this mapping table.
108      * This method should only be used to manipulate the key columns of the
109      * primary table. The secondary table key columns should be manipulated
110      * using MappingReferenceKeyElement methods for pairs.
111      * @param columnName the relative name of the column to be removed
112      * @exception ModelException if impossible
113      */
114     public void removeKeyColumn (String JavaDoc columnName) throws ModelException;
115
116     //===================== reference key handling ===========================
117
118     /** Returns the list of keys (MappingReferenceKeyElements) for this
119      * mapping table. There will be keys for foreign keys and "fake" foreign
120      * keys.
121      * @return the reference key elements for this mapping table
122      */
123     public ArrayList JavaDoc getReferencingKeys ();
124
125     /** Adds a referencing key to the list of keys in this mapping table.
126      * @param referencingKey referencing key element to be added
127      * @exception ModelException if impossible
128      */
129     public void addReferencingKey (MappingReferenceKeyElement referencingKey)
130         throws ModelException;
131
132     /** Removes the referencing key for the supplied table element from list
133      * of keys in this mapping table.
134      * @param table mapping table element for which to remove referencing keys
135      * @exception ModelException if impossible
136      */
137     public void removeReference (MappingTableElement table)
138         throws ModelException;
139 }
140
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