Building Web Apps with Spring 5 and Angular

Update/merge operation

Update or merge operation are Session APIs, which results in an SQL Update. The update() method results in the update of a persistent instance with the ID of the given detached instance, while the merge() method results in the state of the detached instance getting copied onto the persistent object with the same ID. The following are the related APIs:

    void update(Object object) throws HibernateException    void update(String entityName, Object object) throws HibernateException     Object merge(Object object) throws HibernateException    Object merge(String entityName, Object object) throws HibernateException

The following happens as a result of invocation of the update method:

• The detached instance passed to the update method ...