hibernateORM

WEB2 Inclass Project on 2023/(04/19|04/24|04-26|04-27)

04-19:

1.Project created without web

2.hibernate configuration with hibernate.properties files discussed.

04-24:

There are 3 ways to configure hibernate:

1.Using hibernate.properties file:

        InputStream inputStream = Test.class.getClassLoader().getResourceAsStream("res/hibernate-dev.properties");
        Properties properties = new Properties();
        properties.load(inputStream);
        configuration.setProperties(properties);

2.Using hibernate.cfg.xml file:

This should be located at the root of the classpath.

We can make custom configuration xml file.

It should be passed as a parameter in the configuration file

        configuration.configure("hibernate-dev.cfg.xml");

3.Programmetic Configuration

(Without using any configuration file but passing configuration parameters in the code itself)

    Properties properties = new Properties();

    properties.put(Environment.DRIVER, "com.mysql.cj.jdbc.Driver");
    properties.put(Environment.URL, "jdbc:mysql://localhost:3307/orm_db");
    properties.put(Environment.USER, "root");
    properties.put(Environment.PASS, "root");
    properties.put(Environment.DIALECT, "org.hibernate.dialect.MySQL8Dialect");
    properties.put(Environment.SHOW_SQL, "true");
    properties.put(Environment.HBM2DDL_AUTO, "update");
    
    configuration.setProperties(properties);

04-27:

1. Saving a new entity in the database:

Method 1:

    Session session = sessionFactory.getCurrentSession();

    //Transient state
    Session session = sessionFactory.openSession();

    Transaction transaction = session.beginTransaction();

    //Persistent state
    session.persist(student);

    transaction.commit();
    session.close();

Method 2:

    Session session = sessionFactory.openSession();
    session.beginTransaction();

    //Persistent state
    session.save(student);

    session.getTransaction().commit();
    session.close();

2. If the commit is not called, the changes will not be reflected in the database. But table metadata will be created.