Specifying the Database

The Application Server uses the bundled Java DB (Derby) database by default. If the transaction-type element is omitted or specified as JTA and both the jta-data-source and non-jta-data-source elements are omitted in the persistence.xml file, Java DB is used as a JTA data source. If transaction-type is specified as RESOURCE_LOCAL and both jta-data-source and non-jta-data-source are omitted, Java DB is used as a non-JTA data source.

To use a non-default database, either specify a value for the jta-data-source element, or set the transaction-type element to RESOURCE_LOCAL and specify a value for the non-jta-data-source element.

If you are using the default persistence provider, the provider attempts to automatically detect the database based on the connection metadata. You can specify the optional toplink.platform.class.name property to guarantee that the database is correct. For example:

<?xml version="1.0" encoding="UTF-8"?>
    <persistence xmlns="http://java.sun.com/xml/ns/persistence">
        <persistence-unit name ="em1">
            <jta-data-source>jdbc/MyDB2DB</jta-data-source>
            <properties>
                <property name="toplink.platform.class.name" 
                    value="oracle.toplink.essentials.platform.database.DB2Platform"/>
            </properties>
        </persistence-unit>
    </persistence>

The following toplink.platform.class.name property values are allowed. Supported platforms have been tested with the Application Server and are found to be Java EE compatible.

//Supported platforms
oracle.toplink.essentials.platform.database.DerbyPlatform
oracle.toplink.essentials.platform.database.oracle.OraclePlatform
oracle.toplink.essentials.platform.database.SQLServerPlatform
oracle.toplink.essentials.platform.database.DB2Platform
oracle.toplink.essentials.platform.database.SybasePlatform
oracle.toplink.essentials.platform.database.CloudscapePlatform
oracle.toplink.essentials.platform.database.MySQL4Platform
oracle.toplink.essentials.platform.database.PointBasePlatform
oracle.toplink.essentials.platform.database.PostgreSQLPlatform

//Others available
oracle.toplink.essentials.platform.database.InformixPlatform
oracle.toplink.essentials.platform.database.TimesTenPlatform
oracle.toplink.essentials.platform.database.AttunityPlatform
oracle.toplink.essentials.platform.database.HSQLPlatform
oracle.toplink.essentials.platform.database.SQLAnyWherePlatform
oracle.toplink.essentials.platform.database.DBasePlatform
oracle.toplink.essentials.platform.database.DB2MainframePlatform
oracle.toplink.essentials.platform.database.AccessPlatform

To use the Java Persistence API outside the EJB container (in Java SE mode), do not specify the jta-data-source or non-jta-data-source elements if the DataSource is not available. Instead, specify the provider element and any additional properties required by the JDBC driver or the database. If you are using the TopLink Essentials persistence provider, you must specify the toplink.platform.class.name property and the toplink.jdbc.* properties. For example:

<?xml version="1.0" encoding="UTF-8"?>
    <persistence xmlns="http://java.sun.com/xml/ns/persistence">
        <persistence-unit name ="em2">
            <provider>oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider</provider>
            <transaction-type>RESOURCE_LOCAL<transaction-type>
            <non-jta-data-source>jdbc/MyDB2DB</non-jta-data-source>
            <properties>
                <property name="toplink.platform.class.name" 
                    value="oracle.toplink.essentials.platform.database.DB2Platform"/>
                <!-- JDBC connection properties -->
                <property name="toplink.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver"/>
                <property name="toplink.jdbc.url" 
value="jdbc:derby://localhost:1527/testdb;retrieveMessagesFromServerOnGetMessage=true;create=true;"/>
                <property name="toplink.jdbc.user" value="APP"/>
                <property name="toplink.jdbc.password" value="APP"/>
            </properties>
        </persistence-unit>
    </persistence>

For more information about toplink properties, see Additional Database Properties.

For a list of the JDBC drivers currently supported by the Application Server, see the Sun Java System Application Server Platform Edition 9 Release Notes. For configurations of supported and other drivers, see Configurations for Specific JDBC Drivers in Sun Java System Application Server Platform Edition 9 Administration Guide.

To change the persistence provider, see Changing the Persistence Provider.