What is open session in hibernate?
Hibernate SessionFactory openSession() method always opens a new session. We should close this session object once we are done with all the database operations. We should open a new session for each request in multi-threaded environment.
What is difference between getCurrentSession () and openSession () in hibernate?
Difference between openSession and getCurrentSession. Hibernate one to one mapping example….openSession vs getCurrentSession :
|Session object||It always create new Session object||It creates a new Session if not exists , else use same session which is in current hibernate context|
What is difference between session and SessionFactory in hibernate?
SessionFactory is a factory class for Session objects. It is available for the whole application while a Session is only available for particular transaction. Session is short-lived while SessionFactory objects are long-lived. SessionFactory provides a second level cache and Session provides a first level cache.
How save or update works in hibernate?
hibernate. Session class methods, save & saveOrUpdate is, save generates a new identifier and results in an INSERT query, whereas saveOrUpdate does an INSERT or an UPDATE. Save method stores an object into the database. That means it insert an entry if the identifier doesn’t exist, else it will throw error.
Can I reuse the session in hibernate?
So, how can i reuse an Hibernate Session, in the same thread, that has been previously closed? Either use the built-in ” managed ” strategy (set the current_session_context_class property to managed ) or use a custom CurrentSessionContext derived from ThreadLocalSessionContext and override ThreadLocalSessionContet.
What is difference between Merge and update in hibernate?
Difference between merge() and update A merge() method is used to update the database. It will also update the database if the object already exists. An update() method only saves the data in the database. If the object already exists, no update is performed.
Why SessionFactory is used in hibernate?
Most importantly, the SessionFactory in Hibernate is responsible for the creation of Session objects. The Hibernate Session provides methods such as save, delete and update, all of which are used to perform CRUD-based operations on the database to which the SessionFactory connects.
What is the difference between Session and EntityManager?
Session is a hibernate-specific API, EntityManager is a standardized API for JPA. You can think of the EntityManager as an adapter class that wraps Session (you can even get the Session object from an EntityManager object via the getDelegate() function).
What is difference between EntityManager and Session?
Jim, If you’re talking about Hibernate, then the EntityManager and the Hibernate Session are are equivalent. You use the EntityManager if you want to use the Java Persistence API, and Hibernate’s Session if you’re using Hibernate’s API.