Hibernate
/
hibernate-orm
mirror of https://github.com/hibernate/hibernate-orm
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

implemented HHH-58, select id generator 

git-svn-id: https://svn.jboss.org/repos/hibernate/trunk/Hibernate3/doc@5002 1b8cb986-b30d-0410-93ca-fae66ebed9b2
This commit is contained in:
Gavin King 2004-12-19 16:25:07 +00:00
parent 9e5e08ee59
commit c9412d06b9
1 changed files with 41 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
reference/en/modules/basic_mapping.xml
View File

@ -225,7 +225,7 @@
<area id="class19" coords="20 55"/>
<area id="class20" coords="21 55"/>
<area id="class21" coords="22 55"/>
<area id="class21" coords="23 55"/>
<area id="class22" coords="23 55"/>
</areaspec>
<programlisting><![CDATA[<class
name="ClassName"
@ -488,7 +488,7 @@
</sect2>
<sect2 id="mapping-declaration-id" revision="2">
<sect2 id="mapping-declaration-id" revision="3">
<title>id</title>
<para>
@ -682,6 +682,15 @@
</listitem>
</varlistentry>
<varlistentry>
<term><literal>select</literal></term>
<listitem>
<para>
retrieves a primary key assigned by a database trigger by selecting
the row by some unique key and retrieving the primary key value.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>foreign</literal></term>
<listitem>
<para>
@ -696,7 +705,7 @@
</sect3>
<sect3 id="mapping-declaration-id-hilo">
<title>Hi/Lo Algorithm</title>
<title>Hi/lo algorithm</title>
<para>
The <literal>hilo</literal> and <literal>seqhilo</literal> generators provide two alternate
implementations of the hi/lo algorithm, a favorite approach to identifier generation. The
@ -729,7 +738,7 @@
</sect3>
<sect3 id="mapping-declaration-id-uuid">
<title>UUID Algorithm</title>
<title>UUID algorithm</title>
<para>
The UUID contains: IP address, startup time of the JVM (accurate to a quarter
second), system time and a counter value (unique within the JVM). It's not
@ -739,7 +748,7 @@
</sect3>
<sect3 id="mapping-declaration-id-sequences">
<title>Identity columns and Sequences</title>
<title>Identity columns and sequences</title>
<para>
For databases which support identity columns (DB2, MySQL, Sybase, MS SQL), you
may use <literal>identity</literal> key generation. For databases that support
@ -748,13 +757,13 @@
two SQL queries to insert a new object.
</para>
<programlisting><![CDATA[<id name="id" type="long" column="uid">
<programlisting><![CDATA[<id name="id" type="long" column="person_id">
<generator class="sequence">
<param name="sequence">uid_sequence</param>
<param name="sequence">person_id_sequence</param>
</generator>
</id>]]></programlisting>
<programlisting><![CDATA[<id name="id" type="long" column="uid" unsaved-value="0">
<programlisting><![CDATA[<id name="id" type="long" column="person_id" unsaved-value="0">
<generator class="identity"/>
</id>]]></programlisting>
@ -767,13 +776,13 @@
</sect3>
<sect3 id="mapping-declaration-id-assigned">
<title>Assigned Identifiers</title>
<title>Assigned identifiers</title>
<para>
If you want the application to assign identifiers (as opposed to having
Hibernate generate them), you may use the <literal>assigned</literal> generator.
This special generator will use the identifier value already assigned to the
object's identifier property. Be very careful when using this feature to assign
keys with business meaning (almost always a terrible design decision).
object's identifier property. This generator is used when the primary key
is a natural key instead of a surrogate key.
</para>
<para>
@ -785,6 +794,27 @@
</para>
</sect3>
<sect3 id="mapping-declaration-id-select">
<title>Primary keys assigned by triggers</title>
<para>
For legacy schemas only (Hibernate does not generate DDL with triggers).
</para>
<programlisting><![CDATA[<id name="id" type="long" column="person_id">
<generator class="select">
<param name="key">socialSecurityNumber</param>
</generator>
</id>]]></programlisting>
<para>
In the above example, there is a unique valued property named
<literal>socialSecurityNumber</literal> defined by the class, as a
natural key, and a surrogate key named <literal>person_id</literal>
whose value is generated by a trigger.
</para>
</sect3>
</sect2>
<sect2 id="mapping-declaration-compositeid" revision="2">