Update of /cvsroot/nhibernate/nhibernate/doc/reference/en/modules
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv982/en/modules
Modified Files:
basic_mapping.xml
Log Message:
worked on a little bit more.
Index: basic_mapping.xml
===================================================================
RCS file: /cvsroot/nhibernate/nhibernate/doc/reference/en/modules/basic_mapping.xml,v
retrieving revision 1.2
retrieving revision 1.3
diff -C2 -d -r1.2 -r1.3
*** basic_mapping.xml 19 Oct 2004 05:04:00 -0000 1.2
--- basic_mapping.xml 20 Oct 2004 18:08:38 -0000 1.3
***************
*** 38,44 ****
<set name="Kittens">
<key column="mother_id"/>
! <one-to-many class="Cat"/>
</set>
! <subclass name="DomesticCat" discriminator-value="D">
<property name="Name" type="String"/>
</subclass>
--- 38,44 ----
<set name="Kittens">
<key column="mother_id"/>
! <one-to-many class="Eg.Cat, Eg"/>
</set>
! <subclass name="Eg.DomesticCat, Eg" discriminator-value="D">
<property name="Name" type="String"/>
</subclass>
***************
*** 212,216 ****
</callout>
<callout arearefs="class9-co" id="class9">
-
<para>
<literal>polymorphism</literal> (optional, defaults to <literal>implicit</literal>):
--- 212,215 ----
***************
*** 284,287 ****
--- 283,360 ----
</sect2>
+ <sect2 id="mapping-declaration_id">
+ <title>id</title>
+
+ <para>
+ Mapped classes <emphasis>must</emphasis> declare the primary key column of the database
+ table. Most classes will also have a Property holding the unique identifier
+ of an instance. The <literal><id></literal> element defines the mapping from that
+ property to the primary key column.
+ </para>
+
+ <programlistingco>
+ <programlisting><id
+ name="propertyName" <co id="id1-co" linkends="id1" />
+ type="typename" <co id="id2-co" linkends="id2" />
+ column="column_name" <co id="id3-co" linkends="id3" />
+ unsaved-value="any|none|null|id_value" <co id="id4-co" linkends="id4" />
+ access="field|property|nosetter|ClassName"> <co id="id5-co" linkends="id5" />
+
+ <generator class="generatorClass"/>
+ </id> </programlisting>
+ <calloutlist>
+ <callout arearefs="id1-co" id="id1">
+ <para>
+ <literal>name</literal> (optional): The name of the identifier property.
+ </para>
+ </callout>
+ <callout arearefs="id2-co" id="id2">
+ <para>
+ <literal>type</literal> (optional): A name that indicates the NHibernate type.
+ </para>
+ </callout>
+ <callout arearefs="id3-co" id="id3">
+ <para>
+ <literal>column</literal> (optional - defaults to the property name): The
+ name of the primary key column.
+ </para>
+ </callout>
+ <callout arearefs="id4-co" id="id4">
+ <para>
+ <literal>unsaved-value</literal> (optional - defaults to <literal>null</literal>):
+ An identifier property value that indicates that an instance is newly instantiated
+ (unsaved), distinguishing it from transient instances that were saved or loaded
+ in a previous session.
+ </para>
+ </callout>
+ <callout arearefs="id5-co" id="id5">
+ <para>
+ <literal>access</literal> (optional - defaults to <literal>property</literal>): The
+ strategy NHibernate should use for accessing the property value.
+ </para>
+ </callout>
+ </calloutlist>
+ </programlistingco>
+
+ <para>
+ If the <literal>name</literal> attribute is missing, it is assumed that the class has no
+ identifier property.
+ </para>
+
+ <para>
+ The <literal>unsaved-value</literal> attribute is important! If the identfier property of your
+ class does not default to <literal>null</literal>, then you should specify the actual default.
+ This is especially important when using a <literal>System.ValueType</literal> such as
+ <literal>System.Int32</literal> or <literal>System.Guid</literal> as your <literal><id></literal>
+ property. Make sure to explicity set this attribute because <literal>System.ValueType</literal>
+ objects can not be <literal>null</literal>.
+ </para>
+
+ <para>
+ There is an alternative <literal><composite-id></literal> declaration to allow access to
+ legacy data with composite keys. We strongly discourage its use for anything else.
+ </para>
+
+ </sect2>
</sect1>
|
