diff --git a/Doc/course.xml b/Doc/course.xml
index eeb72df40c14773624c16a5471234fe0a12a02d0..519527cf99bb01de4faeaf3a40101f2a98195ddf 100644
--- a/Doc/course.xml
+++ b/Doc/course.xml
@@ -15966,8 +15966,8 @@ Found user 'Fred Wings'</programlisting>
</section>
</section>
- <section xml:id="mappingClasses">
- <title>Mapping classes and database tables</title>
+ <section xml:id="mappingSingleClasses">
+ <title>Mapping single classes and database tables</title>
<section xml:id="transientProperties">
<title>Transient properties</title>
@@ -16113,10 +16113,175 @@ Exception in thread "main" org.hibernate.exception.ConstraintViolationException:
driver as the result of a constraint violation rather than by the
hibernate framework itself prior to attempting the insert.</para>
</section>
+
+ <section xml:id="mappingKeys">
+ <title>Defining multiple keys</title>
+
+ <para>Frequently we need more than just a primary key. Starting from
+ <classname>hibintro.v4.User</classname> we may want to add a
+ property <code>uidNumber</code>. This is a common requirement. On
+ UNIX type operation systems each user does have both a unique login
+ name (like <quote>goik</quote>) and a unique numerical value (like
+ <quote>123</quote>). We choose our primary key to be numeric <coref
+ linkend="uidNumberIsPrimaryKey"/>and the login name to become a
+ second candidate key <coref linkend="uidIsUnique"/>:</para>
+
+ <programlisting>package hibintro.v5;
+...
+@Entity
+@Table(uniqueConstraints={@UniqueConstraint(columnNames={"uid"})}) <co
+ xml:id="uidIsUnique"/>
+public class User {
+
+ int uidNumber;
+ @Id <co xml:id="uidNumberIsPrimaryKey"/> public int getUidNumber() {
+ return uidNumber;
+ }
+ public void setUidNumber(int uidNumber) {
+ this.uidNumber = uidNumber;
+ }
+
+ String uid;
+ @Column(nullable=false) public String getUid() {
+ return uid;
+ }
+ public void setUid(String uid) {
+ this.uid = uid;
+ }
+...</programlisting>
+
+ <para>Notice the slight difference: The <code>uid</code> property
+ needs a <code>nullable=false</code> annotation. This is
+ <emphasis>not</emphasis> automatically inferred from the constraint
+ definition <coref linkend="uidIsUnique"/>. In contrast the property
+ <code>uidNumber</code> is not referenced by the preceding
+ <classname>javax.persistence.Table</classname> annotation but is
+ itself annotated by <classname>javax.persistence.Id</classname>.
+ Hence a <code>nullable=false</code> is not needed.</para>
+
+ <para>The <abbrev
+ xlink:href="http://en.wikipedia.org/wiki/Data_definition_language">DDL</abbrev>
+ reads:</para>
+
+ <programlisting>CREATE TABLE User (
+ uidNumber INT NOT NULL PRIMARY KEY,
+ cname VARCHAR(255) NOT NULL,
+ uid VARCHAR(255) NOT NULL UNIQUE
+)</programlisting>
+ </section>
+
+ <section xml:id="sect_ComposedKeys">
+ <title>Composed keys</title>
+
+ <para>Composed candidate keys are sometimes referred to as business
+ keys. The underlying logic defines which objects are identical based
+ on their values.</para>
+
+ <para>As an example, we consider a company having several
+ departments. The following business rules shall apply:</para>
+
+ <figure xml:id="projectBusinessRules">
+ <title>Business rules for projects</title>
+
+ <orderedlist>
+ <listitem>
+ <para>Each department must have a unique name.</para>
+ </listitem>
+
+ <listitem>
+ <para>A project's name must be unique within the set of all
+ projects belonging to the same department.</para>
+ </listitem>
+
+ <listitem>
+ <para>A project must be assigned to exactly one
+ department.</para>
+ </listitem>
+ </orderedlist>
+ </figure>
+
+ <para>Right now we defer considerations of the n:1 relationship
+ between departments and projects to a later chapter. Instead we
+ focus just on project instances and represent departments just by
+ their integer id values which will later become foreign keys.</para>
+
+ <para>In addition each project receives a unique integer id value as
+ well. This is in accordance with the <quote>best practice</quote>
+ rule of defining a <link
+ xlink:href="http://en.wikipedia.org/wiki/Surrogate_key">surrogate
+ key</link> <coref linkend="projectPrimaryKeyDefinition"/> to be used
+ as (primary) object identifier. This immutable key will then become
+ the target in foreign key definitions:</para>
+
+ <informaltable border="1">
+ <colgroup width="6%"/>
+
+ <colgroup width="94%"/>
+
+ <tr>
+ <td valign="top"><emphasis role="bold">Java</emphasis></td>
+
+ <td valign="top"><programlisting>package hibintro.v6;
+...
+@Entity
+@Table(uniqueConstraints={@UniqueConstraint(columnNames={"name", "department"})}) <co
+ xml:id="projectBusinessKey"/>
+public class Project {
+ int id;
+ @Id <co xml:id="projectPrimaryKeyDefinition"/> public int getId() {return id;}
+ protected void setId(int id) {this.id = id;}
+
+ String name;
+ @Column(nullable=false) public String getName() {return name;}
+ public void setName(String name) {this.name = name;}
+
+ int department;
+ @Column(nullable=false)
+ public int getDepartment() {return department;}
+ public void setDepartment(int department) {this.department = department;}
+...</programlisting></td>
+ </tr>
+
+ <tr>
+ <td valign="top"><emphasis role="bold">Sql</emphasis></td>
+
+ <td><programlisting>CREATE TABLE Project (
+ id int(11) NOT NULL PRIMARY KEY <coref linkend="projectPrimaryKeyDefinition"/>,
+ department int(11) NOT NULL,
+ name varchar(255) NOT NULL,
+ UNIQUE KEY name (name,department)
+)</programlisting></td>
+ </tr>
+ </informaltable>
+
+ <calloutlist>
+ <callout arearefs="projectPrimaryKeyDefinition">
+ <para>Defining the surrogate primary key.</para>
+ </callout>
+
+ <callout arearefs="projectBusinessKey">
+ <para>Defining a business key composed of project name and
+ department number. This implements our second business rule in
+ <xref linkend="projectBusinessRules"/>.</para>
+ </callout>
+ </calloutlist>
+ </section>
+
+ <section xml:id="sect_RenameTablesAndAttributes">
+ <title>Renaming tables and attributes</title>
+
+ <para/>
+ </section>
+
+ <section xml:id="sectChangeDefaultTypeMapping">
+ <title>Changing the default type mapping</title>
+
+ <para/>
+ </section>
</section>
<section xml:id="sect_hibernateValidation">
- <title>Hibernate validation </title>
+ <title>Hibernate validation</title>
<para/>
</section>
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v5/User.java b/ws/eclipse/HibIntro/src/main/java/hibintro/v5/User.java
index 9a09b0c39d01fbd2f6a97a254ba5851a20f4aaa4..d437d3b7b348c529315b984903a90421901006bf 100644
--- a/ws/eclipse/HibIntro/src/main/java/hibintro/v5/User.java
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v5/User.java
@@ -9,7 +9,7 @@ import javax.persistence.UniqueConstraint;
/**
* @author goik
*
- * {@link User} instances with primary key and unique constrait
+ * {@link User} instances with primary key and unique constraint
*
*/
@Entity
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v6/PersistProject.java b/ws/eclipse/HibIntro/src/main/java/hibintro/v6/PersistProject.java
new file mode 100644
index 0000000000000000000000000000000000000000..48851b058176d564b08c1923f839a8879c631c48
--- /dev/null
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v6/PersistProject.java
@@ -0,0 +1,29 @@
+package hibintro.v6;
+
+import hibintro.util.HibernateUtil;
+
+import org.hibernate.Session;
+import org.hibernate.Transaction;
+
+/**
+ * @author goik
+ *
+ * Persisting a simple instance of {@link Project}
+ *
+ */
+public class PersistProject {
+
+ /**
+ * @param args not used.
+ */
+ public static void main(String[] args) {
+ final Session session = HibernateUtil.createSessionFactory("hibintro/v6/hibernate.cfg.xml").openSession();
+
+ final Transaction transaction = session.beginTransaction();
+ {
+ final Project u = new Project("New web-server", 3);
+ session.save(u);
+ }
+ transaction.commit();
+ }
+}
\ No newline at end of file
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v6/Project.java b/ws/eclipse/HibIntro/src/main/java/hibintro/v6/Project.java
new file mode 100644
index 0000000000000000000000000000000000000000..fb6a81279c5afa4d550a0f3f2aeea1a2bc38a1c9
--- /dev/null
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v6/Project.java
@@ -0,0 +1,53 @@
+package hibintro.v6;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+import javax.persistence.UniqueConstraint;
+
+/**
+ * @author goik
+ *
+ * {@link Project} instances with surrogate primary key and composed business key
+ */
+@Entity
+@Table(uniqueConstraints={@UniqueConstraint(columnNames={"name", "department"})})
+public class Project {
+
+ int id;
+ /**
+ * @return The object's immutable database id
+ */
+ @Id
+ public int getId() {
+ return id;
+ }
+ protected void setId(int id) {
+ this.id = id;
+ }
+
+ String name;
+ @Column(nullable=false)
+ public String getName() {
+ return name;
+ }
+ public void setName(String name) {
+ this.name = name;
+ }
+
+ int department;
+ @Column(nullable=false)
+ public int getDepartment() {
+ return department;
+ }
+ public void setDepartment(int department) {
+ this.department = department;
+ }
+
+ public Project() {}
+ public Project(String name, int department) {
+ setName(name);
+ setDepartment(department);
+ }
+}
\ No newline at end of file
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v6/hibernate.cfg.xml b/ws/eclipse/HibIntro/src/main/java/hibintro/v6/hibernate.cfg.xml
new file mode 100644
index 0000000000000000000000000000000000000000..20cc77c28bc2046f51bb29206235497148475c90
--- /dev/null
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v6/hibernate.cfg.xml
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
+ "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
+<hibernate-configuration>
+ <session-factory >
+ <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
+ <property name="hibernate.connection.password">XYZ</property>
+ <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hdm</property>
+ <property name="hibernate.connection.username">hdmuser</property>
+ <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
+ <property name="hibernate.show_sql">true</property>
+ <property name="hibernate.format_sql">true</property>
+ <property name="hibernate.hbm2ddl.auto">update</property>
+
+ <mapping class="hibintro.v6.Project"/>
+ </session-factory>
+</hibernate-configuration>