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| author | nhauge | 2007-05-04 19:55:48 +0000 |
|---|---|---|
| committer | nhauge | 2007-05-04 19:55:48 +0000 |
| commit | bc72d754f082fe30ef0d7aeff54f29c64553f02a (patch) | |
| tree | d69c3c3f38ea93ee78ce6d4529f80d928ee88030 /jpa/plugins/org.eclipse.jpt.doc.user/tasks011.htm | |
| parent | d8139fbb848c9509ae592b5477c85f5fd34b8ceb (diff) | |
| download | webtools.dali-bc72d754f082fe30ef0d7aeff54f29c64553f02a.tar.gz webtools.dali-bc72d754f082fe30ef0d7aeff54f29c64553f02a.tar.xz webtools.dali-bc72d754f082fe30ef0d7aeff54f29c64553f02a.zip | |
178911 - Initial check-in for user.doc plugin for Dali 1.0.
Diffstat (limited to 'jpa/plugins/org.eclipse.jpt.doc.user/tasks011.htm')
| -rw-r--r-- | jpa/plugins/org.eclipse.jpt.doc.user/tasks011.htm | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.doc.user/tasks011.htm b/jpa/plugins/org.eclipse.jpt.doc.user/tasks011.htm new file mode 100644 index 0000000000..cb21d3e933 --- /dev/null +++ b/jpa/plugins/org.eclipse.jpt.doc.user/tasks011.htm @@ -0,0 +1,162 @@ +<!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 3, 2007 9:19:10 --> +<meta name="OAC_IGNORE_SKIP_NAV" content="true" /> +<title>Many-to-many mapping</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="Many-to-many mapping" /> +<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="BABEIEGD" name="BABEIEGD"></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>Many-to-many mapping</h1> +</td> +</tr> +</table> +<p><a id="sthref126" name="sthref126"></a><a id="sthref127" name="sthref127"></a><a id="sthref128" name="sthref128"></a><a id="sthref129" name="sthref129"></a>Use a <span class="bold">Many-to-Many Mapping</span> to define a many-valued association with many-to-many multiplicity. A many-to-many mapping has two sides: the <span class="italic">owning side</span> and <span class="italic">non-owning side</span>. You must specify the join table on the owning side. For bidirectional mappings, either side may be the owning side.</p> +<ol type="1" start="1"> +<li> +<p>In the <a href="ref_persistence_outline.htm#BABEGGFE">JPA Structure view</a>, select the field to map. The <a href="ref_persistence_map_view.htm#BABIFBAF">JPA Details view (for attributes)</a> displays the properties for the selected.</p> +</li> +<li> +<p>In the <span class="gui-object-title">Map As</span> field, select <span class="gui-object-action">Many-to-Many</span>.</p> +</li> +<li> +<p>Use this table to complete the <a href="ref_mapping_general.htm#CACBHFIJ">General information</a> fields of the <span class="gui-object-title">JPA Details</span> view.</p> +<div class="inftblruleinformal"> +<table class="RuleInformal" title="This table lists the fields in the Persistence Properties view for this mapping." summary="This table lists the fields in the Persistence Properties view for this mapping." dir="ltr" border="1" width="100%" frame="border" rules="all" cellpadding="3" cellspacing="0"> +<thead> +<tr align="left" valign="top"> +<th align="left" valign="bottom" id="r1c1-t8">Property</th> +<th align="left" valign="bottom" id="r1c2-t8">Description</th> +<th align="left" valign="bottom" id="r1c3-t8">Default</th> +</tr> +</thead> +<tbody> +<tr align="left" valign="top"> +<td align="left" id="r2c1-t8" headers="r1c1-t8">Map As</td> +<td align="left" headers="r2c1-t8 r1c2-t8">Defines this mapping as a <span class="bold">Many to Many Mapping</span>. +<p>This field corresponds to the <code>@ManyToMany</code> annotation.</p> +</td> +<td align="left" headers="r2c1-t8 r1c3-t8">Many to Many</td> +</tr> +<tr align="left" valign="top"> +<td align="left" id="r3c1-t8" headers="r1c1-t8">Target Entity</td> +<td align="left" headers="r3c1-t8 r1c2-t8">The entity to which this attribute is mapped.</td> +<td align="left" headers="r3c1-t8 r1c3-t8">null +<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> +</tr> +<tr align="left" valign="top"> +<td align="left" id="r4c1-t8" headers="r1c1-t8">Fetch</td> +<td align="left" headers="r4c1-t8 r1c2-t8">Defines how data is loaded from the database. See <a href="ref_mapping_general.htm#CACGGGHB">"Fetch Type"</a> for details. +<ul> +<li type="disc"> +<p>Eager</p> +</li> +<li type="disc"> +<p>Lazy</p> +</li> +</ul> +</td> +<td align="left" headers="r4c1-t8 r1c3-t8">Eager</td> +</tr> +<tr align="left" valign="top"> +<td align="left" id="r5c1-t8" headers="r1c1-t8">Mapped By</td> +<td align="left" headers="r5c1-t8 r1c2-t8">The database field that owns the relationship.</td> +<td align="left" headers="r5c1-t8 r1c3-t8"><br /></td> +</tr> +</tbody> +</table> +<br /></div> +<!-- class="inftblruleinformal" --></li> +<li> +<p>Use this table to complete the fields in the <a href="reference005.htm#CACBAEBC">Join Table Information</a> area in the <span class="gui-object-title">JPA Details</span> view.</p> +<div class="inftblruleinformal"> +<table class="RuleInformal" title="This table lists the fields in the Join Table tab of the Persistence Properties view for this mapping." summary="This table lists the fields in the Join Table tab of the Persistence Properties view for this mapping." dir="ltr" border="1" width="100%" frame="border" rules="all" cellpadding="3" cellspacing="0"> +<thead> +<tr align="left" valign="top"> +<th align="left" valign="bottom" id="r1c1-t9">Property</th> +<th align="left" valign="bottom" id="r1c2-t9">Description</th> +<th align="left" valign="bottom" id="r1c3-t9">Default</th> +</tr> +</thead> +<tbody> +<tr align="left" valign="top"> +<td align="left" id="r2c1-t9" headers="r1c1-t9">Name</td> +<td align="left" headers="r2c1-t9 r1c2-t9">Name of the join table that contains the foreign key column.</td> +<td align="left" headers="r2c1-t9 r1c3-t9">You must specify the join table on the owning side. +<p>By default, the name is assumed to be the primary tables associated with the entities concatenated with an underscore.</p> +</td> +</tr> +<tr align="left" valign="top"> +<td align="left" id="r3c1-t9" headers="r1c1-t9">Join Columns</td> +<td align="left" headers="r3c1-t9 r1c2-t9">Select <span class="bold">Override Default</span>, then Add, Edit, or Remove the join columns.</td> +<td align="left" headers="r3c1-t9 r1c3-t9">By default, the name is assumed to be the primary tables associated with the entities concatenated with an underscore.</td> +</tr> +<tr align="left" valign="top"> +<td align="left" id="r4c1-t9" headers="r1c1-t9">Inverse Join Columns</td> +<td align="left" headers="r4c1-t9 r1c2-t9">Select <span class="bold">Override Default</span>, then Add, Edit, or Remove the join columns.</td> +<td align="left" headers="r4c1-t9 r1c3-t9">By default, the mapping is assumed to have a single join.</td> +</tr> +</tbody> +</table> +<br /></div> +<!-- class="inftblruleinformal" --></li> +<li> +<p>To add a new Join or Inverse Join Column, click <span class="gui-object-action">Add</span>.</p> +<p>To edit an existing Join or Inverse Join Column, select the field to and click <span class="gui-object-action">Edit</span>.</p> +</li> +</ol> +<p>Eclipse adds the following annotations to the field:</p> +<pre xml:space="preserve" class="oac_no_warn"> +@JoinTable(joinColumns=@JoinColumn(name="<span class="italic"><JOIN_COLUMN></span>"), + name = "<span class="italic"><JOIN_TABLE_NAME></span>") +@ManyToMany(cascade=CascadeType.<span class="italic"><CASCADE_TYPE></span>, fetch=FetchType.<span class="italic"><FETCH_TYPE></span>, + targetEntity=<span class="italic"><TARGET_ENTITY></span>, mappedBy = "<span class="italic"><MAPPED_BY></span>") +@OrderBy("<span class="italic"><ORDER_BY></span>") + + +</pre> +<p> </p> +<img src="img/ngrelt.png" alt="Related task" title="Related task" /><br /> +<br /> +<a href="task_mapping.htm#BABDGBIJ">Mapping an entity</a> +<p> </p> +<img src="img/ngrelr.png" alt="Related reference" title="Related reference" /><br /> +<br /> +<a href="ref_persistence_outline.htm#BABEGGFE">JPA Structure view</a><br /> +<a href="ref_persistence_map_view.htm#BABIFBAF">JPA Details view (for attributes)</a> +<p> </p> +<img src="img/ngrelc.png" alt="Related concept" title="Related concept" /><br /> +<br /> +<a href="concept_mapping.htm#BABBDJFI">Understanding OR mappings</a><br /> +<a href="concepts001.htm#BABBGFJG">Understanding EJB 3.0 Java Persistence API</a></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> |