Liferay Service Builder with external database

To make a Liferay Service Builder with external database there are some rules to follow. This post will help you to get straight to the point.
Keep in mind that:

• You can’t deploy more than one portlet mapping column with the same entity name, otherwise you get a hot-Deployment error.

• the names of the portlet name, namespace and database must be distinct (ex. portlet=”imageview“, namespace=”mammography“, database=”dicomviewer“).

• when you add external jar, you must add them in the Tomcat/lib/ext
  so liferay can find them in the global classpath.

The steps to make the service builder with the external database mapping are:

1. make the service.xml file in the /docroot/WEB-INF/
2. launch the build-service ant command
3. add the ext-spring.xml file in the /docroot/WEB-INF/src/META-INF/ folder
4. deploy the portlet.

The example below might be helpful.
—service.xml ————

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE service-builder PUBLIC "-//Liferay//DTD Service Builder 6.0.0//EN" "http://www.liferay.com/dtd/liferay-service-builder_6_0_0.dtd">

<service-builder package-path="it.dicom">
<author>Laura Liparulo</author>
<namespace>mammography</namespace>
<entity name="Volume" local-service="true" remote-service="true" table="volume"
data-source="mammographyDataSource" session-factory="mammographySessionFactory" tx-manager="mammographyTransactionManager">
<!-- PK Fields -->
<column name="volumeId" type="long" primary="true" />
<!-- Other Fields -->
<column name="volumeName" type="String" />
<!-- Relationships -->
<column name="caseVolume" type="Collection" entity="CaseArchive"
mapping-key="volumeId" />
<order by="asc">
<order-column name="volumeName" />
</order>
<finder name="Volume_Name" return-type="Collection">
<finder-column name="volumeName" />
</finder>
</entity>
<entity name="CaseArchive" local-service="true" remote-service="true" table="case_archive"
data-source="mammographyDataSource" session-factory="mammographySessionFactory" tx-manager="mammographyTransactionManager">
<!-- PK Fields -->
<column name="caseId" type="long" primary="true" />
<!-- Other Fields -->
<column name="caseName" type="String" />
<column name="volumeId" type="long" />
<column name="notes" type="String" />
<!-- Relationships -->
<column name="image_Case" type="Collection" entity="Image"
mapping-key="caseId" />
<order by="asc">
<order-column name="caseName" />
</order>
<finder name="Case_Name" return-type="Collection">
<finder-column name="caseName" />
</finder>
</entity>

</service-builder>;
—ext-spring.xml ————

<?xml version="1.0"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
"http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean
class="
org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
</bean>
<bean id="mammographyDataSourceTarget"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/dicomviewer" />
<property name="username" value="root" />
<property name="password" value="tigertailz" />
</bean>
<bean id="mammographyDataSource"
class="org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy">
<property name="targetDataSource">
<ref bean="mammographyDataSourceTarget" />
</property>
</bean>
<bean id="mammographyHibernateSessionFactory"
class="com.liferay.portal.spring.hibernate.PortletHibernateConfiguration">
<property name="dataSource">
<ref bean="mammographyDataSource" />
</property>
</bean>
<bean id="mammographySessionFactory">
<property name="sessionFactoryImplementor">
<ref bean="mammographyHibernateSessionFactory" />
</property>
</bean>
<bean id="mammographyTransactionManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="dataSource">
<ref bean="mammographyDataSource" />
</property>
<property name="sessionFactory">
<ref bean="mammographyHibernateSessionFactory" />
</property>
</bean>
</beans>



http://lauraliparulo.altervista.org/liferay-service-builder-with-external-database/

http://www.liferayaddict.com/home/-/blogs/accessing-database-from-service-other-than-the-default-liferay-database