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[Nhibernate-commit] nhibernate/doc/reference/en/modules basic_mapping.xml,1.1,1.2
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From: Michael D. <mik...@us...> - 2004-10-19 05:04:15
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Update of /cvsroot/nhibernate/nhibernate/doc/reference/en/modules In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv20770 Modified Files: basic_mapping.xml Log Message: worked on it a little bit more. Index: basic_mapping.xml =================================================================== RCS file: /cvsroot/nhibernate/nhibernate/doc/reference/en/modules/basic_mapping.xml,v retrieving revision 1.1 retrieving revision 1.2 diff -C2 -d -r1.1 -r1.2 *** basic_mapping.xml 19 Oct 2004 04:32:01 -0000 1.1 --- basic_mapping.xml 19 Oct 2004 05:04:00 -0000 1.2 *************** *** 138,144 **** --- 138,290 ---- </sect2> + <sect2 id="mapping-declaration-class"> + <title>class</title> + + <para> + You may declare a persistent class using the <literal>class</literal> element: + </para> + + <programlistingco> + + <programlisting><class + name="ClassName" <co id="class1-co" linkends="class1" /> + table="tableName"<co id="class2-co" linkends="class2" /> + discriminator-value="discriminator_value"<co id="class3-co" linkends="class3" /> + mutable="true|false"<co id="class4-co" linkends="class4" /> + schema="owner"<co id="class5-co" linkends="class5" /> + proxy="ProxyInterface"<co id="class6-co" linkends="class6" /> + dynamic-update="true|false"<co id="class7-co" linkends="class7" /> + dynamic-insert="true|false"<co id="class8-co" linkends="class8" /> + polymorphism="implicit|explicit"<co id="class9-co" linkends="class9" /> + where="arbitrary sql where condition"<co id="class10-co" linkends="class10" /> + persister="PersisterClass"<co id="class11-co" linkends="class11" /> + /></programlisting> + <calloutlist> + <callout arearefs="class1-co" id="class1"> + <para> + <literal>name</literal>: The fully qualified .NET Type name of the persistent class + (or interface). + </para> + </callout> + <callout arearefs="class2-co" id="class2"> + <para> + <literal>table</literal>: The name of its database table. + </para> + </callout> + <callout arearefs="class3-co" id="class3"> + <para> + <literal>discriminator-value</literal> (optional - defaults to the class name): A value + that distiguishes individual subclasses, used for polymorphic behaviour. + </para> + </callout> + <callout arearefs="class4-co" id="class4"> + <para> + <literal>mutable</literal> (optional, defaults to <literal>true</literal>): Specifies + that instances of the class are (not) mutable. + </para> + </callout> + <callout arearefs="class5-co" id="class5"> + <para> + <literal>schema</literal> (optional): Override the schema name specified by + the root <literal><hibernate-mapping></literal> element. + </para> + </callout> + <callout arearefs="class6-co" id="class6"> + <para> + <literal>proxy</literal> (optional): Specifies an interface to use for lazy + initializing proxies. You may specify the name of the class itself as long as + all Properties are virtual. + </para> + </callout> + <callout arearefs="class7-co" id="class7"> + <para> + <literal>dynamic-update</literal> (optional, defaults to <literal>false</literal>): + Specifies that <literal>UPDATE</literal> SQL should be generated at runtime and + contain only those columns whose values have changed. + </para> + </callout> + <callout arearefs="class8-co" id="class8"> + <para> + <literal>dynamic-insert</literal> (optional, defaults to <literal>false</literal>): + Specifies that <literal>INSERT</literal> SQL should be generated at runtime and + contain only the columns whose values are not null. + </para> + </callout> + <callout arearefs="class9-co" id="class9"> + + <para> + <literal>polymorphism</literal> (optional, defaults to <literal>implicit</literal>): + Determines whether implicit or explicit query polymorphism is used. + </para> + </callout> + <callout arearefs="class10-co" id="class10"> + <para> + <literal>where</literal> (optional) specify an arbitrary SQL <literal>WHERE</literal> + condition to be used when retrieving objects of this class + </para> + </callout> + <callout arearefs="class11-co" id="class11"> + <para> + <literal>persister</literal> (optional): Specifies a custom <literal>IClassPersister</literal>. + </para> + </callout> + </calloutlist> + </programlistingco> + <para> + It is perfectly acceptable for the named persistent class to be an interface. You would then + declare implementing classes of that interface using the <literal><subclass></literal> + element. You may persist any inner class. You should specify the + class name using the standard form ie. <literal>Eg.Foo+Bar</literal>. + </para> + + <para> + Immutable classes, <literal>mutable="false"</literal>, may not be updated or deleted by the + application. This allows NHibernate to make some minor performance optimizations. + </para> + + <para> + The optional <literal>proxy</literal> attribute enables lazy initialization of persistent + instances of the class. NHibernate will initially return Aspect# proxies which implement + the named interface. The actual persistent object will be loaded when a method of the + proxy is invoked. See "Proxies for Lazy Initialization" below. + </para> + + <para><emphasis>Implicit</emphasis> polymorphism means that instances of the class will be returned + by a query that names any superclass or implemented interface or the class and that instances + of any subclass of the class will be returned by a query that names the class itself. + <emphasis>Explicit</emphasis> polymorphism means that class instances will be returned only + be queries that explicitly name that class and that queries that name the class will return + only instances of subclasses mapped inside this <literal><class></literal> declaration + as a <literal><subclass></literal> or <literal><joined-subclass></literal>. For + most purposes the default, <literal>polymorphism="implicit"</literal>, is appropriate. + Explicit polymorphism is useful when two different classes are mapped to the same table + (this allows a "lightweight" class that contains a subset of the table columns). + </para> + + <para> + The <literal>persister</literal> attribute lets you customize the persistence strategy used for + the class. You may, for example, specify your own subclass of + <literal>NHibernate.Persister.EntityPersister</literal> or you might even provide a + completely new implementation of the interface + <literal>NHibernate.Persister.IClassPersister</literal> that implements persistence via, + for example, stored procedure calls, serialization to flat files or LDAP. See + <literal>NHibernate.DomainModel.CustomPersister</literal> for a simple example (of "persistence" + to a <literal>Hashtable</literal>). + </para> + + <para> + Note that the <literal>dynamic-update</literal> and <literal>dynamic-insert</literal> + settings are not inherited by subclasses and so may also be specified on the + <literal><subclass></literal> or <literal><joined-subclass></literal> elements. + These settings may increase performance in some cases, but might actually decrease + performance in others. Use judiciously. + </para> + + </sect2> + </sect1> + <sect1 id="mapping-quotedidentifiers"> <title>SQL quoted identifiers</title> *************** *** 157,162 **** <property name="itemNumber" column="`Item #`"/> ... ! </class>]]> ! </programlisting> </sect1> --- 303,307 ---- <property name="itemNumber" column="`Item #`"/> ... ! </class>]]></programlisting> </sect1> |
