How to use Hibernate to generate a DDL script from your Play! Framework project

Brian PorterOctober 17th, 2014Last Updated: October 16th, 2014

0 185 1 minute read

Ok, so you have been using the hibernate property name=“hibernate.hbm2ddl.auto” value=“update” to continuously update your database schema, but now you need a complete DDL script?

Use this method from you Global Class onStart to export the DDL scripts. Just give it the package name (with path) of your Entities as well as a file name:

public void onStart(Application app) {
        exportDatabaseSchema("models", "create_tables.sql");
    }
 
    public void exportDatabaseSchema(String packageName, String scriptFilename) {
 
        final Configuration configuration = new Configuration();
        final Reflections reflections = new Reflections(packageName);
        final Set<Class<?>> classes = reflections.getTypesAnnotatedWith(Entity.class);
        // iterate all Entity classes in the package indicated by the name
        for (final Class<?> clazz : classes) {
            configuration.addAnnotatedClass(clazz);
        }
        configuration.setProperty("hibernate.dialect", "org.hibernate.dialect.PostgreSQL9Dialect");
 
        SchemaExport schema = new SchemaExport(configuration);
        schema.setOutputFile(scriptFilename);
        schema.setDelimiter(";");
        schema.execute(Target.SCRIPT, SchemaExport.Type.CREATE );  // just export the create statements in the script
    }