Skip to main content
aboutsummaryrefslogtreecommitdiffstats
blob: 3af72e5211b35f1a7371d46b07cc91297fc44289 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii" />
<meta http-equiv="Content-Style-Type" content="text/css" />
<meta http-equiv="Content-Script-Type" content="text/javascript" />
<title>Many-to-One Mapping</title>
<meta name="copyright" content="Copyright (c) 2000, 2009 oracle . All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this distribution, and is available at http://www.eclipse.org/legal/epl-v10.html. Contributors: Oracle - initial API and implementation" />
<meta name="generator" content="Oracle DARB XHTML Converter (Mode = ohj/ohw) - Version 1.0.11" />
<meta name="date" content="2012-09-13T10:27:41Z" />
<meta name="robots" content="noarchive" />
<meta name="doctitle" content="Many-to-One Mapping" />
<meta name="relnum" content="Release 3.2" />
<meta name="partnum" content="Release 3.2" />
<link rel="copyright" href="dcommon/html/cpyr.htm" title="Copyright" type="text/html" />
<link rel="stylesheet" href="dcommon/css/blafdoc.css" title="Oracle BLAFDoc" type="text/css" />
</head>
<body>
<p class="betadraftsubtitle">Beta Draft: 2012-09-13</p>
<p><a id="CACHAEDB" name="CACHAEDB"></a></p>
<div class="sect3"><!-- infolevel="all" infotype="General" -->
<h1><a id="sthref491" name="sthref491"></a><a id="sthref492" name="sthref492"></a><a id="sthref493" name="sthref493"></a>Many-to-One Mapping</h1>
<div class="inftblhruleinformal">
<table class="HRuleInformal" summary="JPA Details view, One-to-one page" dir="ltr" border="1" width="100%" frame="hsides" rules="rows" cellpadding="3" cellspacing="0">
<col width="29%" />
<col width="*" />
<col width="24%" />
<thead>
<tr align="left" valign="top">
<th align="left" valign="bottom" id="r1c1-t35">Property</th>
<th align="left" valign="bottom" id="r1c2-t35">Description</th>
<th align="left" valign="bottom" id="r1c3-t35">Default</th>
</tr>
</thead>
<tbody>
<tr align="left" valign="top">
<td align="left" id="r2c1-t35" headers="r1c1-t35">
<p>Target entity</p>
</td>
<td align="left" headers="r2c1-t35 r1c2-t35">
<p>The persistent entity to which the attribute is mapped.</p>
<p>You do not need to explicitly specify the target entity, since it can be inferred from the type of object being referenced.</p>
</td>
<td align="left" headers="r2c1-t35 r1c3-t35">
<p>null</p>
</td>
</tr>
<tr align="left" valign="top">
<td align="left" id="r3c1-t35" headers="r1c1-t35">
<p>Fetch</p>
</td>
<td align="left" headers="r3c1-t35 r1c2-t35">
<p>Defines how data is loaded from the database:</p>
<ul>
<li>
<p>Eager &ndash; Data is loaded in before it is actually needed.</p>
</li>
<li>
<p>Lazy &ndash; Data is loaded only when required by the transaction.</p>
</li>
</ul>
</td>
<td align="left" headers="r3c1-t35 r1c3-t35">
<p>Lazy</p>
</td>
</tr>
<tr align="left" valign="top">
<td align="left" id="r4c1-t35" headers="r1c1-t35">
<p>Join fetch</p>
</td>
<td align="left" headers="r4c1-t35 r1c2-t35">
<p>The type of fetch to use:</p>
<ul>
<li>
<p>Inner &ndash; Provides the inner join fetching of the related object.</p>
<p><span class="bold">Note</span>: Inner joining does not allow for null or empty values</p>
</li>
<li>
<p>Outer &ndash; Provides the outer join fetching of the related object</p>
<p><span class="bold">Note</span>: Outer joining allows for null or empty values.</p>
</li>
</ul>
</td>
<td align="left" headers="r4c1-t35 r1c3-t35"><br /></td>
</tr>
<tr align="left" valign="top">
<td align="left" id="r5c1-t35" headers="r1c1-t35">
<p>Optional</p>
</td>
<td align="left" headers="r5c1-t35 r1c2-t35">
<p>Specifies if this field is can be null.</p>
</td>
<td align="left" headers="r5c1-t35 r1c3-t35">
<p>True</p>
</td>
</tr>
<tr align="left" valign="top">
<td align="left" id="r6c1-t35" headers="r1c1-t35">
<p>Cascade</p>
</td>
<td align="left" headers="r6c1-t35 r1c2-t35">
<p>Specify which operations are propagated throughout the entity.</p>
<ul>
<li>
<p>All &ndash; All operations</p>
</li>
<li>
<p>Persist</p>
</li>
<li>
<p>Merge</p>
</li>
<li>
<p>Move</p>
</li>
<li>
<p>Remove</p>
</li>
<li>
<p>Refresh</p>
</li>
</ul>
</td>
<td align="left" headers="r6c1-t35 r1c3-t35">
<p>True</p>
</td>
</tr>
</tbody>
</table>
<br /></div>
<!-- class="inftblhruleinformal" -->
<p>Many-to-one mappings also include the following areas:</p>
<ul>
<li>
<p><a href="reference039.htm#CACIJEGI">Joining Strategy</a></p>
</li>
<li>
<p><a href="reference040.htm#CACGHHGB">Derived Identity</a></p>
</li>
</ul>
</div>
<!-- class="sect3" -->
<!-- Start Footer -->
<div class="footer">
<table class="simple oac_no_warn" summary="" cellspacing="0" cellpadding="0" width="100%">
<col width="86%" />
<col width="*" />
<tr>
<td align="left"><span class="copyrightlogo">Copyright&nbsp;&copy;&nbsp;2011, 2012,&nbsp;Oracle&nbsp;and/or&nbsp;its&nbsp;affiliates.&nbsp;All&nbsp;rights&nbsp;reserved.</span><br />
<a href="dcommon/html/cpyr.htm"><span class="copyrightlogo">Legal Notices</span></a></td>
</tr>
</table>
</div>
<!-- class="footer" -->
</body>
</html>

Back to the top