Example on how you could use Hibernate schema update when creating database migrations for play applications.

PrintSchemaUpdate.java

package play.modules.migrate;

import org.hibernate.dialect.MySQL5Dialect;
import org.hibernate.ejb.Ejb3Configuration;
import org.hibernate.tool.hbm2ddl.DatabaseMetadata;
import play.Play;
import play.db.DB;
import play.db.DBPlugin;
import play.utils.Utils;

import javax.persistence.Entity;
import java.io.File;
import java.sql.SQLException;
import java.util.List;
import java.util.Properties;

/**
 * Example on how you could use Hibernate schema update when creating database migrations for play applications.
 *
 * @author huljas
 */
public class PrintSchemaUpdate {

    public static void main(String[] args) throws SQLException {
        String id = "";
        if (args.length > 0) {
            id = args[0];
        }
        Ejb3Configuration configuration = new Ejb3Configuration();
        Play.init(new File("."), id);
        configuration.setProperty("hibernate.dialect", "play.db.jpa.MySQLDialect");
        Properties fromConf = (Properties) Utils.Maps.filterMap(Play.configuration, "^hibernate\\..*");
        configuration.addProperties(fromConf);
        List<Class> classes = Play.classloader.getAnnotatedClasses(Entity.class);
        for (Class clazz : classes) {
            configuration.addAnnotatedClass(clazz);
        }
        configuration.buildEntityManagerFactory();
        DBPlugin plugin = new DBPlugin();
        plugin.onApplicationStart();
        DatabaseMetadata metadata = new DatabaseMetadata(DB.getConnection(), new MySQL5Dialect());
        String[] sa = configuration.getHibernateConfiguration().generateSchemaUpdateScript(new MySQL5Dialect(), metadata);
        System.out.println("Schema update scripts:");
        for (String s : sa) {
            System.out.println(s);
        }
        System.exit(0);
    }
}