blob: feddf4d807a9fef893ef1ed8100a8bc34ff85ad9 (
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
|
<!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>
<!-- Run date = May 21, 2007 6:35:54 -->
<meta name="OAC_IGNORE_SKIP_NAV" content="true" />
<title>Entity</title>
<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" />
<meta name="generator" content="Oracle DARB XHTML Converter - Version 4.5.3 Build 02" />
<meta name="date" content="2005-07-10T12:57:20+08:00" />
<meta name="robots" content="all" scheme="http://www.robotstxt.org/" />
<meta name="doctitle" content="Entity" />
<meta name="relnum" content="Release 1.0.0" />
<meta name="partnum" content="" />
<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" />
<link rel="start" href="../../index.htm" title="Home" type="text/html" />
<link rel="contents" href="toc.htm" title="Contents" type="text/html" />
</head>
<body>
<p><a id="BABGBIEE" name="BABGBIEE"></a></p>
<div class="sect2"><!-- infolevel="all" infotype="General" -->
<table class="simple oac_no_warn" summary="" cellspacing="0" cellpadding="0" width="100%">
<tr valign="bottom">
<td align="left" width="86%">
<h1>Entity</h1>
</td>
</tr>
</table>
<p><a id="sthref76" name="sthref76"></a><a id="sthref77" name="sthref77"></a><a id="sthref78" name="sthref78"></a><a id="sthref79" name="sthref79"></a>An <span class="bold">Entity</span> is a persistent domain object.</p>
<p>An entity <span class="italic">can be</span>:</p>
<ul>
<li type="disc">
<p>Abstract or concrete classes. Entities may also extend non-entity classes as well as entity classes, and non-entity classes may extend entity classes.</p>
</li>
</ul>
<p>An entity <span class="italic">must have</span>:</p>
<ul>
<li type="disc">
<p>A no-arg constructor (public or protected); the entity class may have other constructors as well.</p>
</li>
</ul>
<p><a id="sthref80" name="sthref80"></a><a id="sthref81" name="sthref81"></a><a id="sthref82" name="sthref82"></a>Each persistent entity must be mapped to a database table and contain a primary key. Persistent entities are identified by the <code>@Entity</code> annotation.</p>
<p>Use this procedure to add persistence to an existing entity:</p>
<ol type="1" start="1">
<li>
<p>Open the Java class in the <span class="gui-object-title">Package Explorer.</span></p>
</li>
<li>
<p>Select the class in the JPA Structure view.</p>
</li>
<li>
<p>In the <span class="gui-object-title">JPA Details</span> view, use the <span class="gui-object-action">Map As</span> field to select <span class="gui-object-action">Entity</span>.</p>
<div class="figure"><a id="sthref83" name="sthref83"></a>
<p class="titleinfigure">Selecting Entity Persistence</p>
<img src="img/persistence_view_entity.png" alt="Selecting entity persistence on the JPA Details view." title="Selecting entity persistence on the JPA Details view." /><br /></div>
<!-- class="figure" --></li>
<li>
<p>Complete the remaining <a href="ref_persistence_prop_view.htm#BABFAEBB">JPA Details view (for entities)</a>.</p>
</li>
</ol>
<p> </p>
<img src="img/ngrelt.png" alt="Related tasks" title="Related tasks" /><br />
<br />
<a href="task_add_persistence.htm#BABHICAI">Adding persistence to a class</a><br />
<a href="task_additonal_tables.htm#CIHGBIEI">Specifying additional tables</a><br />
<a href="task_inheritance.htm#CIHCCCJD">Specifying entity inheritance</a><br /></div>
<!-- class="sect2" -->
<!-- Start Footer -->
<div class="footer">
<table class="simple oac_no_warn" summary="" cellspacing="0" cellpadding="0" width="100%">
<tr>
<td align="left" width="86%"><a href="dcommon/html/cpyr.htm"><span class="copyrightlogo">Copyright © 2006, 2007, Oracle. All rights reserved.</span></a></td>
</tr>
</table>
</div>
<!-- class="footer" -->
</body>
</html>
|
