Schema export with hibernate annotations

问题:

I'm using hibernate annotations and i want to export my database schema.

Similar to the schemaexporttask with hbm xml files.

回答1:

Indeed, the original Hibernate Core SchemaExportTask can only handle Hibernate XML mapping files, not annotations. What you need is the HibernateToolTask that comes with Hibernate Tools.

Here is an Usage example adapted from Java Persistence With Hibernate:

<taskdef name="hibernatetool"
         classname="org.hibernate.tool.ant.HibernateToolTask"
         classpathref="project.classpath"/>
  <target name="schemaexport" depends="compile, copymetafiles"
          description="Exports a generated schema to DB and file">
    <hibernatetool destdir="${basedir}">
      <classpath path="${build.dir}"/>
      <configuration 
          configurationfile="${build.dir}/hibernate.cfg.xml"/>
      <hbm2ddl
          drop="true"
          create="true"
          export="true"
          outputfilename="helloworld-ddl.sql"
          delimiter=";"
          format="true"/>
    </hibernatetool>
</target>

See also

• Hibernate 3 Annotations & Ant

回答2:

You can. Just do it

AnnotationConfiguration configuration = new AnnotationConfiguration();

configuration
.addAnnotatedClass(<TYPE_YOUR_CLASS>.class)
.setProperty(Environment.USER, <TYPE_YOUR_USER>)
.setProperty(Environment.PASS, <TYPE_YOUR_PASSWORD>)
.setProperty(Environment.URL, <TYPE_YOUR_URL>)
.setProperty(Environment.DIALECT, <TYPE_YOUR_DIALECT>)
.setProperty(Environment.DRIVER, <TYPE_YOUR_DRIVER>);

SchemaExport schema = new SchemaExport(configuration);
schema.setOutputFile("schema.sql");

schema.create(<DO_YOU_WANT_TO_PRINT_TO_THE_CONSOLE>, <DO_YOU_WANT_TO_EXPORT_THE_SCRIPT_TO_THE_DATABASE>);

回答3:

In case someone is interested how to do this with JPA+Spring from a unit test (you can generate the sql running the unit test from inside Eclipse like a breeze):

ExportDatabaseSchema.java:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
@TransactionConfiguration(defaultRollback=true)
public class ExportDatabaseSchema {

  @Resource(name="&entityManagerFactory")
  private LocalContainerEntityManagerFactoryBean entityManagerFactory;

  @Test
  public void exportDatabaseSchema(){
    PersistenceUnitInfo persistenceUnitInfo = entityManagerFactory.getPersistenceUnitInfo();
    Map jpaPropertyMap = entityManagerFactory.getJpaPropertyMap();

    Configuration configuration = new Ejb3Configuration().configure( persistenceUnitInfo, jpaPropertyMap ).getHibernateConfiguration();

    SchemaExport schema = new SchemaExport(configuration);
    schema.setOutputFile("resources/sql/schema.sql");
    schema.create(false, false);
  }
}

You need an ExportDatabaseSchema-context.xml:

<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:context="http://www.springframework.org/schema/context"
   xmlns:p="http://www.springframework.org/schema/p"
   xsi:schemaLocation="http://www.springframework.org/schema/beans 
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<import resource="classpath:applicationContext-jpa.xml" /> 
</beans>

The applicationContext-jpa.xml contains the annotation configured entityManagerFactory bean. The trick is to inject it with & like this: "&entityManagerFactory", to dereference the spring generated proxy.

回答4:

Use hibernate3-maven-plugin. Then run 'mvn hibernate3:hbm2ddl'